ICRANet Scientific Report 2011 |
IcranetThe 2011 Scientific ReportPresented toThe Scientific CommitteebyRemo RuffiniDirector of ICRANetICRANet was created by a decision of the Italian Government, ratified unanimously by the Italian Parliament and signed by the President of the Republic of Italy on February 10th 2005. The Republic of Armenia, the Republic of Italy, the Vatican State, ICRA, the University of Arizona and the University of Stanford were the Founding Members. All of them have ratified the Statute of ICRANet (see Enclosure 1). On September 12th 2005 the Board of Governors was established and had its first meeting. Professors Remo Ruffini and Fang Li-Zhi were appointed respectively Director and Chairman of the Board. On December 19th 2006 the Scientific Committee was established and had its first meeting in Washington DC. Prof. Riccardo Giacconi was appointed Chairman and John Mester Co- Chairman. On September 21st 2005 the Director of ICRANet signed with the Ambassador of Brazil Dante Coelho De Lima the adhesion of Brazil to ICRANet. The entrance of Brazil, requested by the President of Brazil Luiz Ignácio Lula Da Silva has been unanimously ratified by the Brazilian Parliament. On February 2009 the board renewed the position of Prof. Fang Li-Zhi as the Chairman of the Board. On December 2009 the Scientific Committee renewed the position of Prof. Riccardo Giacconi as the Chairman of the Committee. On February 2010 the board renewed the position of Prof. Remo Ruffini as the Director of the ICRANet. On August 12th, 2011 the President of Brazil Dilma Rousseff signed the entrance of Brazil in ICRANet (details in http://www.icranet.org/).
During the 2011, we have:
1) The ICRANet Staff In the establishment of the ICRANet Scientific Staff we have followed the previously adopted successful strategy:
This strategy has created an outstanding research institute with strong connections to some of the most advanced Research Centers in the world. It also promotes the vital connections between all the ICRANet Member Institutions. The Curricula of the ICRANet Staff are given in the Accompanying Document “The ICRANet Staff, Visiting Scientists and Graduate Students at the Pescara Center”. PROFESSORS OF THE FACULTY
ADJUNCT PROFESSORS OF THE FACULTY Typically and Adjunct Professor spends at ICRANet a period varying from one month to six months every year and keeps ongoing collaborations for the rest of the year.
LECTURERS The Lecturers participate in the many schools and meetings organized by ICRANet, as well as in the International Relativistic Astrophysics Ph.D. program (IRAP-PhD), sponsored by ICRANet and ICRA (see below). The Lecture series span from a minimum of a few weeks to the entire year.
RESEARCH SCIENTISTS The research scientists are generally at a post-doctoral level and they are extremely active in all research topics.
SHORT-TERM VISITING SCIENTISTS They include experts who have given essential contributions in ongoing activities at ICRANet.
LONG-TERM VISITING SCIENTISTS They are scientists originating from Countries in which the field of relativistic astrophysics is having signs of new developments.
ADMINISTRATIVE STAFF The administrative and secretarial staff of the Center is:
2) The Collaboration with Brazil (see Enclosure 2) The collaboration with Brazil has been articulated in three major points: a) the constitution of the ICRANet Faculty in Brazil, b) the creation of the Brazilian Science Data Center (BSDC), and c) the Cesare Lattes program for exchange of Scientists. 3) Completion of the Seat in Nice: Villa Ratti (see Enclosure 3) We have completed the restructuring of Villa Ratti for the ICRANet Seat in Nice. We been very pleased to receive the invitation by the Municipality of Nice to open ICRANet activities in France, in order to maximize our contacts with other European Countries and more generally with Countries all over the world. The appeal for the town of Nice and his splendid surroundings, the existence of a modern and efficient airport, the electronic backbones for internet communications are all important elements which add to the splendid decision of the Nice Municipality to offer the historical Villa Ratti as a seat for ICRANet in Nice. The first stone for the restructuring of the Villa has been laid down on November 23rd 2007. Since, an important finding of wall paintings of circa 1750 occurred in the Villa. A large amount of activities has being carried out in renovating the building and the park around. The headquarter of the IRAP-PhD program will be in Villa Ratti. 4) International Meetings (see Enclosure 4) We have completed the proceedings of:
We have also organized the following meetings:
5) Scientific Agreements (see Enclosure 5) The following Agreements have been signed, updated and renewed by the Director (see Fig. 1):
These collaborations are crucial in order to give ICRANet scientists the possibility to give courses and lectures in the Universities and, vice versa, to provide to the Faculty of such Universities the opportunity to spend research periods in ICRANet institutions.
6) The International Relativistic Astrophysics Ph.D. (IRAP-PhD) program (see Enclosure 6) One of the major success of ICRANet has been to participate in the International competition of the Erasmus Mundus Ph.D. program and the starting of this program from the 2010 (see Fig. 2). The participating institutions are:
The IRAP PHD program intends to create conditions for high level education in Astrophysics mainly in Europe to create a new generation of leading scientists in the region. No single university in Europe today has the expertise required to attain this ambitious goal by itself. For this reason we have identified universities which offers a very large complementarity expertise. The students admitted and currently following courses and doing research in such a program are given in the following:
We enclose the Posters of the IRAP-PhD for all the above cycles. 7) The Erasmus Mundus Ph.D. program (see Enclosure 7)
Each student admitted to the Erasmus Mundus program of the IRAP Ph.D. will be part of a team inside one of the laboratories of the consortium. Each year they will have the opportunity to visit the other laboratories of the consortium and enlighten themselves with new topics in the forefront research from world leading experts. In this way the students will come in direct contact with some of the leading scientists in the world working in General Relativity, Relativistic Astrophysics and in Quantum Field Theory. In addition to the theoretical centers, we associate experimental and observational center as well. This will provide an opportunity to the Ph.D students to obtain a complete education in theoretical relativistic astrophysics and also an experience on how to carry out a specific astrophysical mission. All the institutions participating in IRAP PhD have an extensive experience in international collaborations including visiting professors, post-doctoral researchers and training of Ph.D. students. All of our partners have enrolled Ph.D. students inside their laboratories in various aspects of astrophysics.
8) Project for the ICRANet Center at Casino de Urca (see Enclosure 8) We have defined the architectural project for the ICRANet Center at the Casino de Urca in Rio de Janeiro, Brazil. 10) Lines of research We turn now to the research activity of ICRANet, which by Statute addresses the developments of research in Astrophysics in the theoretical framework of Albert Einstein’s theories of special and general relativity. Thanks to an unprecedented developments of observational techniques from the ground, from Space, and even in underground experiments in astroparticle physics, we are today capturing signals never before conceived and received in all the history of homo sapiens. The Einstein theory of relativity, for many years relegated to the boundaries of physics and mathematics, has become today the authentic conceptual and theoretical “backbone” of this exponentially growing field of relativistic astrophysics.
In the Report of 2009, as a testimonial of this developments, I enclosed the paper “The Ergosphere and Dyadosphere of Black Holes” which has appeared in “The Kerr spacetime”, edited by David L. Wiltshire, Matt Visser and Susan M. Scott (Cambridge University Press, 2009). In it, I traced the exciting developments, which started with the understanding on the nuclear evolutions of stars, and had then led to the discovery of neutron stars, and through the splendid work of Riccardo Giacconi and colleagues, to the first identification of a black hole in our galaxy. I also enclosed the paper “Moments with Yakov Borisovich Zeldovich” (appeared in the Proceedings of the International Conference “The Sun, the Stars, the Universe, and General Relativity” in honor of Ya.B. Zeldovich's 95th Anniversary, Editors R. Ruffini and G.V. Vereshchagin, AIP Conference Proceedings, Vol. 1205 (2010) p. 1-10), recalling some of the crucial moments in the developments of relativistic astrophysics in Soviet Union around the historical figure of Ya.B. Zeldovich. I recalled how the initial activities of ICRANet were guided by three major scientific components (see Fig. 3), which have indeed seen, in recent times, further important developments:
In the 2009 report I have shown that, thanks to a fortunate number of events and conceptual and scientific resonances, a marked evolution of these topics had occurred. New fields of research had sprouted up from the previous ones at the ICRANet Center in Pescara, at ICRA in Rome and at the other Member Institutions. The synergy created by the theoretical developments and the new astrophysical observations had stimulated novel and important results in a vast range of theoretical topics (see Fig. 7). The topic about the Kerr-Newman Black Holes had been sprouting up in three new fields: The Kerr-Newman Black holes (L, M, Q); The solitonic equations of GR; GR solutions with L, M, Q, X. Kerr-Newman Black Holes (L, M, Q): We had and we have the opportunity of the presence in Pescara of Prof. Roy Kerr as ICRANet Adjunct Professor and discussed the fundamental issues of the uniqueness of the Kerr-Newman Black Hole. A distinct progress in this collaboration has appeared in the paper by D. Bini, A. Geralico, R. Kerr, “The Kerr- Shild ansatz revised”, International Journal of Geometric Methods in Modern Physics (IJGMMP) 7 (2010), 693-703. The solitonic equations of GR: An alternative derivation of the Kerr solution had been advanced in a classical paper of 1978 by V. Belinski and V. Zakharov using inverse scattering method. The generalization of this method to the presence of electromagnetic field was constructed in 1980 by G. Alekseev and Kerr-Newman solution has been derived by him in analogous way at the same year. Prof. V. Belinski is now an ICRANet Faculty Member and has further developed this research with the effective collaboration of Prof. G. Alekseev which is an ICRANet Lecturer. This activity was presented at the 12th Marcel Grossmann Meeting and at number of other conferences and has reached a new maturity. GR solutions with L, M, Q, X: The unsolved problem of a physical solution in general relativity of an astrophysical object which must be characterized necessarily by four parameters, mass, charge, angular momentum and quadrupole moment, has also been debated for years and it is yet not satisfactorily solved. The presence of ICRANet of Prof. Quevedo as an Adjunct Professor has shown an important result published by Bini, Geralico, Longo, Quevedo [Class. Quant. Grav., 26 (2009), 225006]. This result has been obtained for the special case of a Mashhooon-Quevedo solution characterized only by mass, angular momentum and quadrupole moment. It has been shown that indeed such a Mashhoon-Quevedo solution can be matched to an internal solution solved in the post- Newtonian approximation by Hartle and Thorne for a rotating star. Similarly, the Gamma-Ray Bursts topic had been sprouting up two additional new fields: Ultra high energy sources and Supernovae. Gamma-Ray Bursts: The research on GRBs in ICRANet is wide and has been participated by many Members of the Faculty and of the Adjunct Faculty, as well as by many Lecturers, Research Scientists and graduate students. Traditionally, GRBs are divided into two classes, “short” GRBs and “long” GRBs, arranged in a bimodal distribution with a separation around a duration of 2s. In 2001 we proposed that both short and long GRBs are created by the same process of gravitational collapse to a black hole. The energy source is the e+e- plasma created in the process of the black hole formation. The two parameters characterizing the GRB are the total energy Ee± tot of such an e+e- plasma and its baryon loading B defined as B=MBc2/Ee± tot, where MB is the mass of the baryon loading. The e+e- plasma evolves as a self-accelerating optically thick fireshell up to when it become transparent, hence we refer to our theoretical model as the “fireshell model”. We have defined a “canonical GRB” light curve with two sharply different components. The first one is the Proper-GRB (P-GRB), which is emitted when the optically thick fireshell becomes transparent and consequently has a very well defined time scale determined by the transparency condition. The second component is the emission due to the collision between the accelerated baryonic matter and the CircumBurst Medium (CBM). This comprises what is usually called the “afterglow”. The relative energetics of the two components is a function of B. For B < 10-5 the GRB is “P-GRB dominated”, since the P-GRB is energetically dominant over the second component. The contrary is true for B larger than such a critical value. Since 2001 it has been a major point of our theoretical model that the long GRBs are simply identified with the peak of this second component. As such, they don’t have an intrinsic time scale: their duration is just a function of the instrumental noise threshold. This prediction has been strongly supported by the observations of Swift and now of Fermi and Agile satellites. It is now clear, therefore, that the duration usually quoted as characterizing the so-called long GRB class is not related to intrinsic properties of the source but it only depends on the instrumental noise threshold. This is quite different from the case of the short GRBs. In the last year report we have strengthen our aim to identify different families of GRBs originating from different precursors. Ultra high energy sources: This additional topic was motivated by the interaction with Brian Punsly and was well documented in his volume “Black hole gravitohydromagnetics” (Springer) as well as in the joining of ICRANet by Prof. Felix Aharonian as representative of Armenia in the Scientific Committee and by his appointment as the Adjunct Professor of ICRANet. Many of the observational work done by Prof. Aharonian are crucial for the theoretical understanding of the ultra high energy sources. Prof. Aharonian started also his collaboration with the IRAP PhD program where he is following the thesis of graduate students as thesis advisor. Supernovae: GRBs have broaden the existing problematic of the study of Supernovae. In some models, e.g. the “collapsar” one, all GRBs are assumed to originate from supernovae. Within our approach, we assume that core-collapse supernovae can only lead to neutron stars, and we also assume that GRBs are exclusively generated in the collapse to a black hole. Within this framework, supernovae and GRBs do necessarily originate in a binary system composed by an evolved main sequence star and a neutron star. The concept of induced gravitational collapse leads to the temporal coincidence between the transition from the neutron star to the black hole and the concurrent transition of the late evolved star into a supernova. Support to our model was given in last year report by GRB 0606014. The above mentioned binary systems are expected to be by far the most frequent, but they are the less energetics and they are observable only up to redshifts z < 0.5. We gave reason in the lat year report that the most energetic GRBs do originate from the merging of binary systems formed by two neutron stars or a neutron star and a white dwarf, not giving rise to a supernova. This very wide topic has been promoted by the collaboration with Prof. Massimo Della Valle, who is an Adjunct Professor at ICRANet. This kind of research is particularly important for trying to find a coincidence between electromagnetic radiation, high-energy particles, ultra high-energy cosmic rays and gravitational radiation, possible observable for existing or future detectors. Similarly, the Relativistic Quantum Field Theory topic has been sprouting up two additional new fields: “Von Kerner Zum Sterner” and Plasma Thermalization. “Von Kerner Zum Sterner”: A multi-year study in ICRA and ICRANet has been devoted to the relativistic Thomas-Fermi equations. The early work was directed to the analysis of superheavy nuclei. In the last years, a special attention has been given to formulate a unified approach which, on one side, describes the superheavy nuclei and, on the other, what we have called “Massive Nuclear Cores”. These last ones are systems of about 1057 nucleons, kept together in beta equilibrium and at nuclear density due to the effect of self gravity. The most surprising result has been that the analytic treatment used by Prof. Popov and his group in their classical work on superheavy nuclei can be scaled to the Massive Nuclear Core regime in presence of gravity. The consequences of this is that an electric field close to the critical value Ec = me 2c3/(e) can be found on the surface layer of such Massive Nuclear Cores. This fortunate result has triggered a great interest and has opened what it can be considered a new approach to the electrodynamics of neutron stars within ICRANet.
Relativistic Quantum Field Theory: A major effort in the last years has been to review the electron-positron creation and annihilation processes in physics and astrophysics. Particularly in the paper by Ruffini, Vereshchagin, Xue [Phys. Rep. 487 (2010) 1-140] there are reviewed the conceptual developments which led Dirac to describe the system e+e- 2g, Breit Wheeler to describe the system 2g e+e- and the classical papers of Sauter, Euler, Heisenberg and Schwinger to the analysis of vacuum polarization and pair creation in an overcritical electric field Ec = me 2c3/(e). In addition three ultrarelativistic processes have been in depth reviewed. They deal with (1) the vacuum polarization process in the field of a Kerr-Newman black hole; (2) the feedback of the electron-positron pair creation on the overcritical electric field; and (3) the thermalization process of the created e+e- plasma. This reports, with more than 500 references, gives the background necessary to initiate the study of the quantum field theory description of the electrodynamical approach in the process of gravitational collapse. Plasma thermalization: The physics of electron-positron plasma has appeared to be relevant for GRBs, but also for the Early Universe, in laboratory experiments with ultraintense lasers etc. We study both nonequilibrium effects such as thermalization and associated timescales, as well as dynamical effects such as accelerated expansion in the optically thick regime. Relativistic numerical codes are designed and widely implemented in this research. The basic outcomes include: determination from the first principles of relaxation timescales of optically thick electron-positron plasma with baryonic loading in the wide range of plasma parameters; conclusion that deviations from a simple "frozen radial profile" in spatial distributions of energy and matter densities of expanding electron-positron plasma with baryonic loading are possible. The last conclusion imply in particular the possibility to recover the spatial distribution of matter and energy in the process of collapse of a GRB progenitor to a black hole. Out of these developments twelve scientific presentation were presented in the last meeting of the Scientific Committee. In Fig. 8 there are presented in blue the topics of selected oral presentations to the Scientific Committee on December 14th–15th, 2009. In 2010 report all the topics have further developed and strengthened and additional topics have sprouted, as it is shown in Fig. 9, where the projection of these researches are represented. This has led to a deeper understanding of the initial field of research, but has led as well to a wider number of fundamental topics covered by the scientific programs developed at ICRANet. In this 2011 report we report the consolidation of this program by reviewing a few of them, which will also be presented in the oral contributions of this Scientific Meeting. The topic of BKL cosmology is one of the most important and classical contributions of Einstein theory to the study of cosmology. This classic work, developed by Belinski, Kalatnikov and Lifshitz, has already been reviewed in all the major treaties on general relativity, but only recently a new insight has come from the impressive discoveries made by Thibault Damour at the IHES in Paris, by Prof. Mark Henneaux at the University of Bruxelles, and by Herman Nicolai at the Albert Einstein Institute in Potsdam, on the way to generalize the BKL theory of cosmological singularity to the string theories. The new results can be of essential importance for understanding the problem of cosmological singularity and for the identification of hidden internal symmetries in fundamental physics. Prof. Belinski has already finished his part of a new book on “Cosmological singularities” which will written in co-authorship with Prof. Damour. The book has planned to be published by Cambridge University Press. A shortened and adapted version of this book has already been presented in the AIP conference proceedings of XIV Brazilian School of Cosmology and Gravitation (V. Belinski “On the Singularity Phenomenon in Cosmology”, in: Chapter 2, Cosmology and Gravitation: XIV Brazilian School of Cosmology and Gravitation, Cambridge Scientific Publishers, 2011). Three graduate students of the IRAP PhD program are actually working on this topic for their theses with Profs. Hagen Kleinert and Hermann Nicolai in Berlin (Dutta, Fleig, and Gruber). On a different topic, during the last year the solitonic solutions of GR has received new interest in respect of the exact solutions of Einstein and Einstein-Maxwell equations: a) The old problem how to generate the exact stationary axisymmetric solutions corresponding to the charged masses with horizons in the framework of Inverse Scattering Method (ISM) was investigated. It was shown that applicability of the ISM in presence of electromagnetic field is not restricted only to the cases with naked singularities (as it have been erroneously stated by some authors). In fact solutions of Einstein-Maxwell equations with horizon also follows from ISM and they are of the same solitonic character. The mathematical procedure of analytical continuations of the naked-singularity solitonic solutions in the space of their parameters which procedure results in solitonic solutions with horizon has been described (G. Alekseev and V. Belinski “Soliton Nature of Equilibrium State of Two Charged Masses in General Relativity”, arXiv:gr-qc/1103.0582, IJMP(D) in press, 2011); b) It was found the new way of derivation of the Kerr solution by adding to the Schwarzchild black hole the solitonic vortex made from the pure gravitational field. With this method, one can figure out how rotational energy can contribute to the mass of the resulting Kerr black hole. Also the relation of the Hanson- Regge type between the mass and angular momentum of a Kerr black hole has been established and its connection with the Christodoulou-Ruffini concept of irreducible mass was analyzed (V. Belinski and H. W. Lee “Kerr rotation as solitonic whirl around Schwarzschild black hole”, Nuovo Cimento, submitted, 2011). The full report is on Page 1. The report on Gamma-Ray Bursts starts on page 11. Major progresses have been accomplished this year in the following aspects: 1) In well identifying the origin of the new GRB family which we have defined as “disguised short” GRBs, the prototype being GRB 970228 confirmed by GRB 060614, by GRB 071227, and by GRB 050509B; all these objects appear to be related to progenitors formed by binary systems of neutron stars or a neutron star and a white dwarf. 2) In identifying the offset of disguised GRB host galaxies as a key parameter to classify this kind of sources. 3) In understanding the role of the “Amati” relation for the disguised short GRBs. 4) In studying the possible selection effect preventing the identification of “genuine”' short GRBs (see Figs. 10-11). 5) In evidencing a broadening of the spectral energy distribution within the fireshell model for highly energetic GRBs (about 1053 - 1054 erg). 6) In identifying a new family of very energetic sources (GRB 080319B and GRB 050904); both these sources are at an energy of 1054 erg and they offer unprecedented opportunities since one is located at z ~ 1 and the other at z ~ 6.3: the nearby source allow a most significant high-quality data on very short time scale which has allowed to reach a deeper understanding of the instantaneous spectrum vs. the average one. 7) New outlook has been brought to this field by the Fermi and AGILE satellites and the very exciting preliminary results have been obtained on GRB 080916C and GRB 090902B. 8) In studying the P-GRB observed spectra (see Fig. 11). 9) Particularly exciting is the new possibility of having components yet to be observed in GRB sources. In fact, we have shown that it is not possible to interpret GRB 090618 and GRB 101023 within the framework of the traditional single component GRB model. We argue that the observation of the first episode of duration of around 50s could not be a part of a canonical GRB, while the residual emission could be modeled easily as a canonical GRB. This led to the definition of the novel concept of “proto-black hole emission” (see Figs. 12-18). Particularly interesting is also the possible collaboration with Brazil on space projects (see the report on page 353).
In the report “Relativistic effects in Physics and Astrophysics” (see page 291) it is studied the distribution of the GRB bolometric luminosity over the EQTSs, with special attention to the prompt emission phase. We analyze as well the temporal evolution of the EQTS apparent size in the sky. We use the analytic solutions of the equations of motion of the fireshell and the corresponding analytic expressions of the EQTSs which have been presented in recent works and which are valid for both the fully radiative and the adiabatic dynamics. We find the novel result that at the beginning of the prompt emission the most luminous regions of the EQTSs are the ones closest to the line of sight. On the contrary, in the late prompt emission and in the early afterglow phases the most luminous EQTS regions are the ones closest to the boundary of the visible region (see Fig. 19). We find as well an expression for the apparent radius of the EQTS in the sky, valid in both the fully radiative and the adiabatic regimes. Such considerations are essential for the theoretical interpretation of the prompt emission phase of GRBs.
The collaboration on Supernovae is mainly centered from almost daily scientific contact with Prof. Massimo Della Valle, who is currently PI of a VLT proposal “A spectroscopic study of the supernova/GRB connection”. A short summary of the internationally well-known activities of Prof. Della Valle, who is an Adjunct Professor at ICRANet, is given in the report on page 409, which contains the many publications in international journals. Prof. Della Valle is also very active following one graduate student of the IRAP PhD program. The Report on “Cosmology and Large Scale Structures” on page 429 manifests the progress made by the ICRANet group at the University of Arizona. It deals with three different topics. A. Turbulence behavior of cosmic baryon gas. With hydrodynamic simulation sample of the LCDM universe produced by the WENO algorithm, we show that the intermittency of the velocity field of cosmic baryon fluid at redshift z=0 in the scale range from the Jeans length to about 16h-1 Mpc can be extremely well described by the She- Lévĕque's scaling formula, which is used to describe a fully developed turbulence. We also found that the non-Gaussian features of the cosmic baryon fluid and Ly-a transmitted flux of quasar absorption spectrum can be well described by a log-Poisson hierarchy. B. Wouthuysen-Field coupling. With a state-of-the-art numerical method, we show that the resonant scattering of Ly-a photons with neutral hydrogen atoms will lock the color temperature of the photon spectrum around the Ly-a frequency to be equal to the kinetic temperature of hydrogen gas. The time scales of the onset of Wouthuysen-Field coupling, the profile of frequency distribution of photons in the state of local thermal equilibrium, the effects of the expansion of the universe on the Wouthuysen-Field coupling in a optical thick halos have also been found. These results are essential for studying the 21 cm signal from high redshift sources. C. Time-dependent behavior of Lya photon transfer. Lya photons have been widely applied to study cosmological problems in high redshifts. Since the time scales of high redshift sources, such as GRBs, generally are short, time-dependent solutions of Lya photon transfer becomes serious. However, no reliable numerical solvers of the time-dependent problem of radiative transfer equation with resonant scattering have been developed till 2006. The time-dependent solver (Meiksin, MN, 370, (2006), 2025- 2037) still cannot pass the test of analytical solutions (Field, ApJ, 129, (1959), 551). The solver based on the WENO scheme has been established. It can very well pass various tests (Roy et al ApJ, 716, 2010, 604). It reveals many interesting features of the time evolution of resonant photons Lya in optical thick medium. It provides the solutions of studying the time-dependent effect of resonant scattering on the profile of red damping wing of GRBs. It is crucial to understand the halos of GRBs. The Report “Theoretical Astroparticle Physics” on page 479 represents the summary of activities during the last year on this topic by the group including: Carlo Luciano Bianco, Massimiliano Lattanzi, Remo Ruffini, Gregory Vereshchagin, She-Sheng Xue. Students working within the group include: Micol Benetti, Alberto Benedetti, Damien Begue, Eloisa Menegoni, Stefania Pandolfi, Ivan Siutsou. Astroparticle physics is a new field of research emerging at the intersection of particle physics, astrophysics and cosmology. We focused on several topics with three major directions of research: a) electron-positron plasma, b) photospheric emission from ultrarelativistic outflows, c) correlation dynamics in cosmology, d) neutrinos and large scale structure formation in cosmology, e) semidegenerate self-gravitating systems of fermions as a model for dark matter halos and f) constraining cosmological models with CMB observations. Electron-positron plasma appear relevant for GRBs and also for the Early Universe, in laboratory experiments with ultraintense lasers, etc. We study nonequilibrium effects such as thermalization and associated timescales, dynamical effects such as accelerated expansion in the optically thick regime and the photospheric emission from relativistic plasma. Relativistic kinetic and hydrodynamic numerical codes are designed and widely implemented in this research. We examine the quantum corrections to the collision integrals and determine the timescales of relaxation towards thermal equilibrium for high temperature electron-positron-photon plasma. Since in such case the characteristic timescales of two-body and three-body interactions are no longer different, the collision integrals for three-particle interactions have to be computed directly from the QED matrix elements, similar to the two-body interactions. We point out that unlike classical Boltzmann equation for binary interactions such as scattering, more general interactions are typically described by four collision integrals for each particle that appears both among incoming and outgoing particles (A.G. Aksenov, R. Ruffini. I.A. Siutsou and G.V. Vereshchagin, “Bose enhancement and Pauli blocking in the pair plasma”, in preparation). These results extend the previous results obtained in A.G. Aksenov, R. Ruffini and G.V. Vereshchagin, Physical Review D, Vol. 79 (2009) 043008; Physical Review Letters, Vol. 99 (2007) No 12, 125003, and oral report on this topic will be made by I.A. Siutsou. Using relativistic Boltzmann equations we study microphysical interactions and photon emission from optically thick relativistic electron-positron plasma initially energy-dominated and confined to a spherical region. Due to numerical limitations we cannot consider very high optical depths relevant for GRBs. However we may follow the process of self acceleration and formation of the shell which reaches mildly relativistic bulk velocity of expansion before it becomes transparent for radiation, similarly to electron-positron plasma in GRB sources. We follow dynamical evolution of particle number density, optical depth, hydrodynamic velocity, luminosity and spectra. We find unexpectedly that the spectrum of emission near its peak is different from pure thermal one, and contains more power in the low energy part of the spectrum (A.G. Aksenov, R. Ruffini. I.A. Siutsou and G.V. Vereshchagin, “Dynamics and emission ofmildly relativistic plasma”, to appear in proceedings of the 2nd Galileo-XuGuangqi meeting, 12-17 July 2010, Hanbury Gardens, Ventimiglia, Italy). The oral report on this topic will be made by G.V. Vereshchagin. We investigate the behavior of the electron-positron pairs created by a strong electric field. This problem has been studied in our previous work (A. Benedetti, W.-B. Han, R. Ruffini and G.V. Vereshchagin, Physics Letters B, Vol. 698 (2011) 75-79.) using simple formalism based on continuity and energy-momentum conservation equations. Now we extend that work using the more general kinetic approach (A.G. Aksenov, R. Ruffini and G.V. Vereshchagin, Physical Review D, Vol. 79 (2009) 043008). It allows us to obtain some new results. Simultaneous creation and acceleration of electron-positron pairs in an external electric field creates a peculiar distribution of pairs in momentum space. After few oscillations this distribution relaxes to a certain equilibrium which may be characterized by two “temperatures”: orthogonal and parallel to the direction of electric field. The orthogonal temperature is much smaller than the parallel one. The internal energy intrinsic to this peculiar distribution of pairs in the momentum space after few oscillations dominates the energy budget of the system, thus damping oscillations significantly, compared to the simple above mentioned treatment. The effects of interactions with photons are also under investigation (A. Benedetti, R. Ruffini and G.V. Vereshchagin, “Evolution of the pair plasma generated by a strong electric field”, in preparation). The oral report on this topic will be made by A. Benedetti. We consider analogies and differences of physical conditions of electron-positron plasma in GRBs and in cosmology. In particular, we derive the basic conservation equations which are valid for electronpositron plasma both in GRBs and in the early Universe. We show that the range of number densities and temperatures for both cases are similar, and consequently nuclear reprocessing should take place in GRB sources, similarly to the cosmological nucleosynthesis. Finally, we obtain the lower limit on the temperature in GRB plasma before it reaches the transparency condition. This lower limit turns out to be extremely insensitive to the basic parameters and initial conditions, being always higher than the ionization potential of hydrogen. It implies that hydrogen recombination does not occur in GRB plasma, unlike the early Universe (R. Ruffini and G.V. Vereshchagin, ”Electronpositron plasma in GRBs and in cosmology”, in preparation (2011)). The oral report on this topic will be made by G.V. Vereshchagin. We study the photospheric emission from ultrarelativistic outflows, focusing on dynamics of photospheres and relativistic effects (see Figs. 20-21). It is our main finding that the photospheric emission appears non thermal, and may be described by the Band function well known in the GRB literature, when time integrated spectra are analyzed. We also find that only time integrated spectra may be observed from energetic GRBs (R. Ruffni, I. A. Siutsou and G. V. Vereshchagin, “Theory of photospheric emission from relativistic outflows”, submitted to the Astrophysical Journal (2011)). The oral report on this topic will be made by G.V. Vereshchagin.
In the framework of cosmology two fundamental processes are known to occur in a self-gravitating system of collisionless massive particles: gravitational instability and violent relaxation. A new analytic approach is aimed in describing these two apparently distinct phenomena as different manifestations of essentially the same physical process: gravitational structure formation. This approach is based on application of two averaging schemes: spatial averaging and coarse-graining. A master equation for spatially averaged coarse grained distribution function of dark matter is constructed and its limiting cases are analyzed. Discussion of the related works, such as the recent work of J. Einasto et al., (A&A, 531, A75, 2011) discussing phase synchronization in the large scale structure is presented (R. Ruffini and G.V. Vereshchagin and R. Zalaletdinov, ”Correlation dynamics in cosmology”, in preparation (2011)). The oral report on this topic will be made by G.V. Vereshchagin. We show how the distribution of Dark Matter (DM) in galaxies can be explained within a model based on a semidegenerate self-gravitating system of fermions in General Relativity. We reproduce the observed properties of galaxies as the core, the halo, as well as the flattening of the rotation curves. In order to account for the evaporation phenomena (the escape velocity) we introduced a cut-off in the fermion momentum space. The model provides physical interpretation of phenomenological pseudo-isothermal sphere and Burkert DM profiles. It is consistent with a mass of the DM particle of the order of 14 KeV, compatible with a possible sterile neutrino interpretation. The oral report on this topic will be made by I.A. Siutsou. Constraining cosmological models with Cosmic Microwave Background observations: Precision measurement of the cosmological observables have led to believe that we leave in a flat Friedmann Universe, seeded by nearly scale-invariant adiabatic primordial fluctuations. The majority (∼ 70%) of the energy density of the Universe is in the form of a fluid with a cosmological constant-like equation of state (w ∼ −1), dubbed dark energy, that is responsible for the observed acceleration of the Universe. This socalled concordance model is adequately described by just six parameters, namely the baryon density, the cold dark matter density, the Hubble constant, the reionization optical depth, the amplitude and the spectral index of the primordial spectrum of density fluctuations. These parameters are measured to a very high precision. However, even if the concordance model gives a very satisfactory fit of all available data, it is worth to consider extended models and to constraint their parameters. In some cases these extended models simply arise when considering properties that, to a first approximation, can be neglected when interpreting cosmological data. This is the case for parameters like the neutrino mass and the curvature of the Universe. Both are very small and can be put to zero as a first approximation; however, allowing them to vary allows to put useful constraints on their value. Cosmology can set bounds on both the active and sterile neutrino masses, as well as on the number of sterile neutrino species. Indeed, neutrino oscillation experiments have brought to light the first departure from the standard model of particle physics, indicating that neutrinos have nonzero masses and opening the possibility for a number of extra sterile neutrinos. We find that models with two massive sub-eV sterile neutrinos plus three sub-eV active states are perfectly allowed at the 95% CL by current cosmic microwave background, galaxy clustering, and Supernova Ia data (Giusarma et al. Phys. Rev. D., Vol 83 (2011) 115023). This bounds have been obtained in the context of a ΛCDM cosmology, and other scenarios with a dark energy component could allow for larger neutrino masses and/or abundances. We have also shown that big bang nucleosynthesis helium-4 and deuterium abundances exclude (3+2) models at the 95% CL. However, the extra sterile states do not necessarily need to feature thermal abundances at decoupling. Their precise abundances are related to their mixings with the active neutrinos in the early Universe. Moreover, we have found that future cosmological data like those from the Planck satellite are expected to measure sub-eV active and sterile neutrino masses and sterile abundances with 10-30% precision, for sub-eV (0.5 eV> mν >0.1 eV) sterile neutrino masses (E. Giusarma et al. Phys. Rev. D., Vol 83 (2011) 115023). We have also shown that the presence of massive sterile neutrinos in the Universe could be inferred from inconsistencies among the values of H0 obtained from cosmic microwave and galaxy clustering probes and those arising from independent measurements of the Hubble constant over the next decade. Comparing cosmological measurements of the active neutrino mass with those obtained from tritium beta-decay experiments could also test the validity of the cosmological assumptions. The oral report on this topic will be made by S. Pandolfi. In the concordance model, reionization is assumed to happen instantaneously. Indeed, details of the reionization processes in the late universe are not very well known and thus a more realistic description is definetely in order. We have explored the imprints of general reionization histories on the CMB spectra. Making use of the parameterization of reionization based on a principal component approach we have deduced information about tensor modes, and explored how the inflation constraints are modified when the standard reionization assumption is relaxed (S. Pandolfi et al, Phys. Rev. D Vol 82 (2010), 123527). The tensor-to-scalar ratio bounds are largely unmodified under more general reionization scenarios. Therefore, present (future) primordial gravitational wave searches are (will be) unaffected by the precise details of reionization processes. Hybrid models, ruled out in the standard reionization scheme, are still allowed at the 95% c.l. by WMAP7 data. The constraints on other inflationary models, such as large-field or small-field models, do not change. With the aim of constraining the evolution of cosmic reionization, we also have extended the previous work based on the use of Principal Components analysis (Pandolfi et al., accepted for publication in Phys. Rev. D). The main novelty of our analysis is represented on one hand by complementing available CMB data with additional astrophysical results from quasar absorption line experiments, as the Gunn- Peterson test and the redshift evolution of Lyman Limit Systems. In addition, we have for the first time explored the effects of a joint variation of both the cosmological and astrophysical parameters. We have concluded that inclusion of astrophysical datasets, allowing to robustly constrain the reionization history, in the extraction procedure of cosmological parameters leads to relatively important differences in the final determination of their values. There is ample experimental evidence showing that fundamental couplings run with energy, and many particle physics and cosmology models suggest that they should also roll with time. In fact, both the European Space Agency (ESA) and the European Southern Observatory (ESO) now list varying fundamental constants among their key science drivers for the next generation of facilities. In particular the presence of a scalar field at recombination could induce variations in the fine structure constant. While the effects of a cosmological constant at recombination are completely negligible, dynamical scalar fields could track the dominant energy component, be present at the recombination and induce variations in α if coupled to the electromagnetic sector. Searching for relations in the variations of the fine structure constant and a non-negligible scalar field at recombination, it is possible to describe the scalar field with a Early Dark Energy. We have modified the CAMB code for early dark energy including the variations of the fine structure constant and, using WMAP-7 years data and HST data, constrained the variation of and the coupling between the scalar field and the electromagnetic sector. Moreover, we have performed a Fisher matrix analysis in order to assess the future sensitivity to these parameters from CMB data, in particular from Planck and CMBPol. (E. Calabrese et al., Phys. Rev. D Vol. 84 (2011) 023518). The oral report on this topic will be made by E. Menegoni. Cosmological observations are in excellent agreement with the inflationary prediction of adiabatic primordial perturbations with a nearly scale-invariant power spectrum. In its simplest implementation, inflation is driven by the potential energy of a single scalar field, the inflaton, slowly rolling down towards a minimum of its potential and in more general inflationary models, there is the possibility that slow roll is briefly violated. A violation of slow-roll (due for example to phase transitions occurring during the slow roll in multi-field inflationary model) will possibly lead to detectable effects on the cosmological observables, or at least to the opportunity to constraint these models by the absence of such effects. In particular, step-like features in the primordial power spectrum have been shown to lead to characteristic localized oscillations in the power spectrum of the primordial curvature perturbation. Such oscillations have been considered as a possible explanation to the “glitches” observed by WMAP in the temperature anisotropy spectrum of the CMB. We have updated the constraints on possible features in the primordial inflationary density perturbation spectrum using the latest data from WMAP7 and ACT Cosmic Microwave Background experiments (Benetti et al., Phys. Rev. D Vol 84 (2011) 063509). In particular, we have compared the theoretical predictions of a specific model, i.e., chaotic inflation, and of a more general phenomenological model to the WMAP7 and ACT data, in order to find constraints on the parameter describing the model. We have found that models with features can improve the fit to the WMAP7 data when the step in the potential is placed in way to produce oscillations in the region 20 < l < 60, i.e., in correspondence of the WMAP glitches. Increasing the dataset with ACT data, we found confirmation but not further evidence for small scales glitches; however, models with too high step are excluded by the data. We can conclude that models with a step provide a significantly better fit than standard featureless power-law spectra, even if there is not a clear statistical evidence in the data for extensions to the simplest inflationary model. We have also found that forthcoming temperature and polarization data from Planck will allow to measure the model parameters with remarkable precision, possibly confirming the glitches presence in the region 20 < l < 60. The oral report on this topic will be made by M. Benetti. The most important metrics in general relativity is the Kerr-Newman solution which describes the gravitational and electromagnetic fields of a rotating charged mass, characterized by its mass M, charge Q and angular momentum L in geometrical units. This solution characterizes the field of a black hole. For astrophysical purposes, however, it is necessary to take into account the effects due to the moment of inertia of the object. To attack this problem, an exact solution of the Einstein-Maxwell equations have been proposed by Mashhoon and Quevedo which posses an infinite set of gravitational and electromagnetic multipole moments. It is not clear, however, how this external solution to an astrophysical object can be matched to a physical internal solution corresponding to a physically acceptable rotating mass. The report “Generalization of the Kerr-Newman solution” on page 685 reports on current progresses in using an explicit solution of the Hartle-Thorne equation to an eternal solution with N independent quadrupole moments. The report on “Cosmology and non linear relativistic field theories” on page 833 covered a wide range thematic in cosmology and non linear relativistic field theory studied by Prof. M. Novello and his group. This include the geometrical description of quantum mechanics where it is shown that quantum mechanics could be interpreted as a modification of the euclidean nature of a 3D space into a particular affine space. In this formulation, deformation of physical distances are in the core of quantum effects allowing a geometrical formulation of the uncertainty principle. Prof. Novello also studied the Higgs mechanism without Higgs boson. The purpose of this work is to show that the gravitational interaction is able to generate mass for all body. It is extremely important with the LHC experiment which soon will enlight us about the existing or not of the Higgs particle. A main part of his activity is related to bouncing cosmology. The report on Black Holes and Quasars refers to the activity of Prof. Brian Punsly (see page 849), who is actively participating within ICRANet with the publication of his internationally recognized book on “Black hole gravitohydromagnetics”, the first and second edition (2010) being published with Springer. In addition, Prof. Punsly have been interested in observational properties of quasars such as broad line emission excess in radio loud quasars accentuated for polar line of sight and excess narrow line widths of broad emission lines in broad absorption line quasars, showing that this is best explained by polar lines of sight. The problem “The electron-positron pairs in physics and astrophysics: from heavy nuclei to black holes” has been the subject of a physics reports of more than 500 references, which is inserted on page 955, by Ruffini, Vereshchagin and Xue. There, all the different aspects of the field has been reviewed: The fundamental contributions to the electron-positron pair creation and annihilation and the concept of critical electric field; Nonlinear electrodynamics and rate of pair creation; Pair production and annihilation in QED; Semi-classical description of pair production in a general electric field; Phenomenology of electron-positron pair creation and annihilation; The extraction of blackholic energy from a black hole by vacuum polarization processes; Plasma oscillations in electric fields; Thermalization of the mildly relativistic pair plasma. Due to the interaction of physics and astrophysics we are witnessing in these years a splendid synthesis of theoretical, experimental and observational results originating from three fundamental physical processes. They were originally proposed by Dirac, by Breit and Wheeler and by Sauter, Heisenberg, Euler and Schwinger. For almost seventy years they have all three been followed by a continued effort of experimental verification on Earthbased experiments. The Dirac process, e+e- → g, has been by far the most successful. It has obtained extremely accurate experimental verification and has led as well to an enormous number of new physics in possibly one of the most fruitful experimental avenues by introduction of storage rings in Frascati and followed by the largest accelerators worldwide: DESY, SLAC etc. The Breit-Wheeler process, 2g → e+e-, although conceptually simple, being the inverse process of the Dirac one, has been by far one of the most difficult to be verified experimentally. Only recently, through the technology based on free electron X-ray laser and its numerous applications in Earth-based experiments, some first indications of its possible verification have been reached. The vacuum polarization process in strong electromagnetic field, pioneered by Sauter, Heisenberg, Euler and Schwinger, introduced the concept of critical electric field. It has been searched without success for more than forty years by heavy-ion collisions in many of the leading particle accelerators worldwide. In view of the recent developments in the free electron lasers, we have invited at ICRANet Prof. John Madey, the inventor of the free electron lasers, to give a set of lectures (see enclosure 9) and to explore the possibility to have, by focusing the free electron laser signals, the realization in the laboratory of the Breit-Wheeler process. Prof. Madey has also accepted the position of Adjunct Professor at ICRANet, and he is planning a collaboration with us in the forthcoming years. In the report on page 855, using the formula obtained for the rate of pair production in spatially varying external electric field dynamical equations describing the space and time evolutions of pair-induced electric charges, currents and fields bounded within a given spatial region are solved. These results imply the wave propagation of the pairinduced electric field and wave-transportation of the electromagnetic energy in the strong field region. Analogously to the electromagnetic radiation emitted from an alternating electric current, the space and time variations of pair-induced electric currents and charges emit an electromagnetic radiation. We show that this radiation has a peculiar energyspectrum that is clearly distinguishable from the energy-spectra of the bremsstrahlung radiation, electron–positron annihilation and other possible background events. This possibly provides a distinctive way to detect the radiative signatures for the production and oscillation of electron–positron pairs in ultra-strong electric fields that can be realized in either ground laboratories or astrophysical environments. (Wen-Biao Han, Remo Ruffini, She-Sheng Xue “Electron–positron pair oscillation in spatially inhomogeneous electric fields and radiation” Physics Letters B 691 (2010) 99). We study the frequency of the plasma oscillations of electrons-positron pairs created by the vacuum polarization in an uniform electric field in the range 0.2Ec < E < 10Ec. We work out one second order ordinary differential equation for the velocity from which we can recover the plasma oscillation equation as a limiting case with vanishing E. For this reason, we focus our attention on its evolution in time studying how this oscillation frequency approaches the plasma frequency. Also the time scale needed to approach the plasma frequency and the power spectrum of these oscillations are computed. The spectrum of this dipole radiation shows a unique line-like feature, as discussed above. The position of this feature, is determined as a function of the initial value of electric field strength. (A. Benedetti , W.-B. Han, R. Ruffini, G.V. Vereshchagin, “On the frequency of oscillations in the pair plasma generated by a strong electric field”, Physics Letters B6 98 (2011) 75). The e+e− pairs generated by the vacuum polarization process around a gravitationally collapsing charged core are entangled in the electromagnetic field (R. Ruffini, L. Vitagliano, S.-S. Xue, Phys. Lett. B 573, (2003) 33), and thermalize in an electron– positron–photon plasma on a time scale ~ 104 tC (R. Ruffini, L. Vitagliano, S.-S. Xue, Phys. Lett. B 559, (2003) 12). As soon as the thermalization has occurred, the hydrodynamic expansion of this electrically neutral plasma starts (R. Ruffini, J. Salmonson, J. Wilson, S.-S. Xue, Astronomy and Astrophysics Vol. 335 (1999) 334; Vol. 359 (2000) 855). While the temporal evolution of the e+e− gravitationally collapsing core moves inwards, giving rise to a further amplified supercritical field, which in turn generates a larger amount of e+e− pairs leading to a yet higher temperature in the newly formed e+e−g plasma. We study this theoretically challenging process, which is marked by distinctive and precise quantum and general relativistic effects, and follow the dynamical phase of the formation of Dyadosphere and of the asymptotic approach to the horizon by examining the time varying process at the surface of the gravitationally collapsing core. We conclude that the core is not discharged or, in other words, the electric charge of the core is stable against vacuum polarization and electric field is amplified during the gravitational collapse. As a consequence, an enormous amount of pairs is left behind the collapsing core and Dyadosphere (G. Preparata, R. Ruffini, S.-S. Xue, Astronomy and Astrophysics Vol. 338 (1998) L87) is formed. Recently, we study this pair-production process in a neutral collapsing core, rather than a charged collapsing core, as described above. Neutral stellar cores at or over nuclear densities are described by positive charged baryon cores and negative charged electron gas since they possess different masses and interactions (equations of state). In static case, the equilibrium configuration of positive charged baryon cores and negative charged electron gas described by Thomas-Fermi equation shows an overcritical electric field on the surface of baryon core. Based on such an initial configuration and a simplified model of spherically collapsing cores, we approximately integrate the Einstein-Maxwell equations and the equations for the particle number and energy-momentum conservations. It is shown that in gravitational core-collapse, such an electric field dynamically evolves in the space-time and electron-positron pairs are produced and gravitational energy is converted to electron-positron energy, leading to the Dyadosphere of electron-positron pairs. This important result has been submitted to Physics Review Letter for publication (W. B. Han, R. Ruffini, S.-S. Xue, see report on page 1255). The oral report on this topic will be made by S.-S. Xue (see Figs. 22-23).
We turn now to the report From nuclei to compact stars on page 1267. This activity has been carried out by a collaboration between D. Arnett, H. Kleinert, V. Popov, M. Rotondo, J. Rueda, R. Ruffini and S.-S. Xue. One of the most active field of research has been to analyze a general approach to Compact Stars like White-Dwarfs and Neutron Stars, based on the Thomas-Fermi ultrarelativistic equations amply adopted in the study of superheavy nuclei. The analysis of superheavy nuclei has historically represented a major field of research, developed by Prof. V. Popov and Prof. W. Greiner and their schools. In 2007 the ICRANet group found the welcome result that all the analytic work developed by Prof. V. Popov and the Russian school can be applied using scaling laws satisfied by the relativistic Thomas-Fermi equation to the case of nuclear matter cores of stellar dimensions, if the beta equilibrium condition is properly taken into account. Since then, a large variety of problems has emerged, which have seen the direct participation of the above mentioned ICRANet Faculty and Adjunct Faculty staff. In a set of seven appendixes, they have been presented the recent progresses made in the intervening years. First, the consideration made for an isolated core with constant proton density whose boundary has been sharply defined by a step function. No external forces are exerted. Then when the assumption of a sharp proton density profile has been relaxed and, consequently, a smooth surface modeled by a Woods-Saxon-like proton distribution has been introduced. The analysis of globally neutral and compressed configurations composed by a relativistic fluid of degenerate neutrons, protons, and electrons in beta equilibrium has been recently accomplished. It has been generalized the Feynman- Metropolis-Teller treatment of compressed atoms to relativistic regimes, and the concept of compressed nuclear matter cores of stellar dimensions has been introduced. Finally we studied the construction of neutron star configurations within a fully consistent formulation of the equations of equilibrium in general relativity and strong interactions, which is being covered currently in the Ph. D. thesis of D. Pugliese, R. Belvedere and S. Martins de Carvalho (see Fig. 24). This entire program has been developed in order to identify the initial boundary conditions for the electrodynamical process occurring at the onset of gravitational collapse leading to a black hole. An oral presentation of these topics will be made by J. Rueda.
In parallel to this work on the neutron star, the introduction of the techniques for solving a compressed atom in a Wigner-Seitz cell has allowed to give a new approach to the study of degenerate matter in white dwarfs. This problem presents, still today, open issues of great interest such as the equilibrium of the electron gas and the associated nuclear component, taking into account the electromagnetic, the gravitational and the weak interactions formulated in a correct special and general relativistic framework. A complete analysis of the properties of such configurations as a function of the compression can be duly done through the relativistic generalization of the Feynman-Metropolis-Teller approach. It is then possible to derive a consistent equation of state for compressed matter which generalizes both the uniform free-electron fluid approximation, adopted for instance by Chandrasekhar in his famous treatment of white-dwarfs, and the well-known work of Salpeter which describes the electrodynamical and relativistic effects by a sequence of approximations. Apart from taking into account all possible electromagnetic and special relativistic corrections to the equation of state of white-dwarf matter, the new equation of state, which incorporates the beta equilibrium condition, leads to a selfconsistent calculation of the onset for inverse beta-decay of a given nuclear composition as function of the Fermi energy of electrons or equivalently, as a function of the density of the system. This important achievement, leads to a self-consistent calculation of the critical mass of white-dwarfs with heavy nuclear composition. In addition, the numerical value of the mass, of the radius, and of the critical mass of white-dwarfs turn to be smaller with respect to the ones obtained with approximate equations of state. Therefore, the analysis of compressed atoms following the relativistic Feynman-Metropolis-Teller treatment has important consequences in the determination of the mass-radius relation of white dwarfs, leading to the possibility of a direct confrontation of these results with observations, in view of the current great interest for the cosmological implications of the type Ia supernovae. These two topics are leading to the preparation of a new book with Springer with the title “Von Kerner zum Sterner”. The generalization of the general relativistic theory of white dwarfs to the rotating case is part of the thesis work of K. Boshkayev. The entire family of uniformly rotating stable white dwarfs has been already obtained by studying the mass-shedding, the inverse b-decay, as well as the axisymmetric instabilities. The maximum mass and the minimum (maximum) rotation period (frequency) have been obtained for selected nuclear compositions. These results are relevant both for the theory of type Ia supernovae as well as for the recent work of M. Malheiro, J. Rueda and R. Ruffini on the description of Soft- Gamma-Ray Repeaters (SGRs) and Anomalous X-Ray Pulsars (AXPs) as rotation powered white dwarfs, following a pioneer idea of M. Morini et al. (1988) and of B. Paczynski (1990) on the AXP 1E 2259+586. The recent observation of SGR 0418+5729 promises to be an authentic Rosetta Stone, a powerful discriminant for alternative models of SGRs and AXPs. The loss of rotational energy of a neutron star cannot explain the X-ray luminosity of SGR 0418+5729, excluding the possibility of identifying this source as an ordinary spindown powered neutron star. The inferred upper limit of the surface magnetic field of SGR 0418+5729 B < 7.5x1012 G, describing it as a neutron star within the magnetic braking scenario, is well below the critical magnetic field Bc=2pm2 ec3/(he) ~ 4.4x1013 Gauss, challenging the power mechanism based on magnetic field decay purported in the magnetar scenario. We have shown that the observed upper limit on the spin-down rate of SGR 0418+5729 is, instead, perfectly in line with a model based on a massive fast rotating highly magnetized white dwarf of fiducial mass M=1.4MSun, radius R=103 km, and moment of inertia I ~ 1049 g cm2. We have analyzed the energetics of all SGRs and AXPs including their steady emission, the glitches and their subsequent outburst activities. It can be then shown that the occurrence of the glitch, the associated sudden shortening of the period, as well as the corresponding gain of rotational energy, can be explained by the release of gravitational energy associated to a sudden contraction and decrease of the moment of inertia of the white dwarfs, consistent with the conservation of their angular momentum. The energetics of the steady emission as well as the one of the outbursts following the glitch can be simply explained in term of the loss of the rotational energy in view of the moment of inertia of the white dwarfs, much larger than the one of neutron stars. There is no need here to invoke the decay of ultrastrong magnetic fields of the magnetar model (see Figs. 25,27).
S. Martins de Carvalho is working on the influence of the temperature on the properties of the core and the crust of the novel globally neutral neutron star equilibrium configurations. The traditional study of neutron star cooling has been generally applied to quite old objects as the Crab Pulsar (957 years) or the Central Compact Object in Cassiopeia A (330 years) with an observed surface temperature ~ 106 K. However, recent observations of the late (t=108-109 s) emission of Supernovae associated to GRBs (GRB-SN) show a distinctive emission in the X-ray regime consistent with temperatures ~ 107-108 K. Similar features have been also observed in two Type Ic Supernova SN 2002ap and SN 1994I not associated to GRBs. We have recently advanced the possibility that such a late (t=108-109 s) X-ray emission observed in GRB-SN and in isolated SN is associated to a hot neutron star just formed in the Supernova event, what we have defined as a neo-neutron star. The major role played by the neutrino emissions from the crust of a neo-neutron star at the initial stages of the object is illustrated in Fig. 26. We have shown that the presence of an additional heating source H0 ~ 1012-1015 erg/g/s (or H0 ~ 10-6-10-3 MeV/Nucleon/s) in the evolution of the neo-neutron star at early times, is enough to match the late X-ray emission of the GRB-SN. Particularly interesting in this respect are the processes of e+e- pair creation expected to occur in the interface between the core and the crust during the neutron star formation leading to the appearance of critical fields. It is also worth to mention that the above numerical value of H0, is in striking agreement with the heat released from nuclear fusion reactions, radiative neutron captures and photodisintegrations that take place e.g. in the early stages of neutron star mergers. All this suggests the exciting possibility that we are, for the first time, observing a nascent hot neutron star. This possibility alone warrants further studies on this subject, so we might obtain a more concrete picture of the thermal evolution of neo-neutron stars. An oral presentation of these specific results will be made by R. Negreiros.
The topic about Symmetries in General Relativity (the full report is on page 1633) has been developed as an intense collaboration between various research groups. Profs. R.T. Jantzen, L. Stella (Observatory of Monte Porzio, Rome), O. Semerak (Czech Republic), D. Bini and Dr. A. Geralico have studied the problem of motion of test particles in black hole spacetimes, in presence of a superposed radiation field. The scattering of radiation by the test particles causes a friction-like drag force which forces particles on certain equilibrium orbits outside the black hole horizon. This interesting effect, known as Poynting-Robertson effect, has been deeply investigated in many different contexts: besides the Schwarzschild and Kerr black hole, novel results have been published for the case of a Vaidya radiation metric. In the latter case, in fact, one takes the advantages of having an exact solution of the Einstein’s field equations whose source is a null field. Among the various consequences we mention that while a unique equilibrium circular orbit exists if the photon flux has zero angular momentum, multiple such orbits appear if the photon angular momentum is sufficiently high. Furthermore other solutions of the Weyl class with cylindrical symmetry as well as solutions within the class of exact gravitational plane waves and electromagnetic plane waves have been examined in the context of Poynting-Robertson like effects obtaining a number of physically relevant situations. Bini and Geralico have also considered the motion of spinning test particles in Kerr spacetime in full generality with the aim to study deviations between the world lines of spinning objects in comparison with those of geodesic test particles, generalizing some recent works on the same topic where motion were but constrained on the equatorial plane. Bini, Geralico and Jantzen have been able to obtain new foliations in spacetimes admitting separable geodesics. These “separable geodesic action slicing” have been used then to explore certain geometrical properties of horizon penetrating coordinates in black hole spacetimes. Other collaborations, again for what concerns the topics included in symmetries in General Relativity, have been started with Profs. A. Ortolan (INFN Legnaro, Padova, Italy) and P. Fortini (University of Ferrara, Italy) to study of the interaction of electromagnetic waves with gravitational waves, with the gravitational waves considered in the exact theory and not in its linear approximation. In collaboration with Campus Bio-Medico in Rome there are ongoing researches on galactic structures. The Reports “Self Gravitating Systems, Galactic Structures and Galactic Dynamics” on page 1741 is focused on analytical and numerical methods for the study of classical self-gravitating fluid/gaseous masses. A series of papers of this group have been devoted in the past to the generalization of the classical theory of ellipsoidal figures of equilibrium using virial methods. The research activities of the group have focused subsequently on functional methods for obtaining equilibrium solutions for polytropic self-gravitating systems that rotate and have a non uniform vorticity. The group has recently published a novel and important result in the context of analogous geometry theory. It is well known that the wave equation for the perturbations of given a perfect barotropic and irrotational Newtonian fluid can be rewritten as an “effective General Relativity”. They have extended this result including the possibility for the fluid to be self-gravitating. This work opens the path for a new interpretation of classical whitedwarf theory in terms of curved space-time techniques. The group has also studied the perturbations of classical compressible rotating but not gravitating fluids as occurring in generalized acoustic black holes. It has also analyzed the Analog Gravity formalism at full nonlinear level through Von Mises’ Wave Equation for irrotational configurations. We recall the successful attempt of applying methodologies developed in Relativistic Astrophysics and Theoretical Physics to researches in the medicine domain. The Report “Interdisciplinary Complex Systems” on page 1771 adopts analytical and numerical methods for the study of problems of nonlinear dynamics focusing on biological systems and using a theoretical physics approach. It is well established both numerically and experimentally that nonlinear systems involving diffusion, chemotaxis, and/or convection mechanisms can generate complicated time-dependent spiral waves, as in happens in chemical reactions, slime molds, brain and in the heart. Because this phenomenon is global in Nature and arises also in astrophysics with spiral galaxies, the goal of this research activity has been to clarify the role of this universal spiraling pattern. The group has studied numerically the nonlinear partial differential equations of the theory (Reaction-Diffusion) using finite element methods. The group has recently published moreover a novel and important result: an electromechanical model of cardiac tissue, on which spiral moves and causes the domain to deform in space and time (see Fig. 28). This model is a real breakthrough in the context of theoretical biophysics, leading to new scenarios in the context of computational cardiology. In 2011 the group has focused its research on classical hydrodynamics, evaluating the stress exerted by the fluid on the domain walls and introducing an indicator of risk for their damage. Such a methodology, named as “three-band decomposition analysis of wall shear stress in pulsatile flows”, has been immediately applied to hemodynamical problems which have been numerically integrated (see Fig. 29), but results promising also for other problems of physical and biological sciences and for engineering.
The next contribution is the one by Jaan Einasto of the Tartu Astronomical Observatory. Prof. Einasto has been collaborating in the previous year intensively within ICRA about the large scale structure of the Universe and its possible fractal structure. With Prof. Einasto there is also the collaboration of Prof. G. Hutsi. Since two years Prof. Einasto is an Adjunct Professor of ICRANet and an active member of the Faculty of the IRAP PhD. In this role Prof. Einasto has delivered a set of lectures in the months of February and September 2010 on “The large scale structure of the universe: a powerful probe for fundamental physics”. This topic was covered with a quantitative analysis of the distribution of galaxies, on dark matter, on the cosmological parameters and dark energy. At the moment, Prof. Einasto has been invited to prepare a book reviewing the status of the dark matter and the large scale structure of the universe by World scientific. This book is going to cover the material of the lectures delivered in the IRAP PhD program as well as an historical perspective between the different approaches to the study of the dark matter content of the universe in the west and in the former Soviet union. The full report is on page 1789, which is followed by the lecture delivered at the 12th Marcel Grossmann Meeting in the occasion of the presentation to him of the Marcel Grossmann award. An important fundamental research topic is the investigation of “analogue models of gravity”. Such models have been used to understand many aspect of gravitational phenomena, in particular the mechanism of Hawking- and Unruh-Radiation, by studying in supersonic flow nozzles. These were of great help in dispersing criticism of these radiations based on our ignorance of the divergences of local quantum field theory at ultrashort distances. Another important analogy is bases on the relation between Einstein- Cartan Physics and the theory of defects in solids, worked out in detail in the textbook by our adjunct faculty members H. Kleinert: http://users.physik.fu-berlin.de/~kleinert/kleinert/?p=booklist&details=1. This analogy has recently allowed to understand the equivalence of Einstein's theory of gravitation with his Teleparallel Theory of Gravitation as a result of a novel gauge symmetry. The first uses only the curvature of spacetime to explain gravitational forces, while the second uses only torsion. The equivalence relies on the fact that crystalline defects of rotation and translation (disclinations and dislocations, respectively) are not independent of each other, but the ones can be understood as superpositions of the other. Moreover, the analogy has allowed to set up an infinite family of intermediate theories in which curvature and torsion appear both http://klnrt.de/385/385.pdf. Finally, all geometries relevant in gravitational physics has been derived from a completely new theory of multivalued fields http://users.physik.fu-berlin.de/~kleinert/kleinert/?p=booklist&details=9. A volume dedicated to Fermi and Astrophysics has been edited in the recent years and has been finally completed (“Fermi and Astrophysics”, edited by D. Boccaletti and R. Ruffini, World Scientific, 2011). This book has some different goals: 1) to present some papers which were published at ICRA in the occasion of the centenary of the birth of Enrico Fermi; 2) to translate into English a set of papers by Fermi which were available only in Italian; 3) to try to understand the reason why, having been one of the greatest experts on Einstein theory in the earliest years of his life, after his transfer to Rome and later on to the United States Fermi never published anything on Einstein theory. In the latest part of his life Fermi realized that astrophysics offers a great future to physics. The only paper by Fermi mastering general relativity and cosmology was to prove George Gamow work being wrong. On the contrary, he managed in matter of fact to give one of the greatest contribution to cosmology and to Gamow theory and to Einstein theory of general relativity. Other books which are currently in preparation are:
Finally, there will be an oral presentation by Pascal Chardonnet of the current situation of the IRAP PhD and the Erasmus Mundus program co-sponsored by the European Commission, as well as a report on the first nineteen graduate students enrolled in the program (see enclosure 7). Acknowledgements I am very happy to express, on behalf of all the Members of ICRANet and myself, our profound gratitude to the Minister of Foreign Affairs, to the Minister of Economy and Finances of Italy. Gratitude as well is expresses to the Minister of University and Research of Italy for the support of ICRA, which collaborates with ICRANet on all activities within Italy. Special gratitude to Prof. Immacolata Pannone for her continuous attention to the ICRANet activities since their beginning, as well as to the Ragioneria Generale of the Ministry of Economy and Finances, for their daily attention in the activities of ICRANet. A special recognition goes to the activities of the many Ambassadors and Consuls who have greatly helped in the intense series of activities carried out by ICRANet in Belarus, Brazil, France, China, Korea and New Zealand. Special gratitude to Minister Gherardo La Francesca who first signed the Seat Agreement of ICRANet in Pescara, then unanimously ratified by the Italian Parliament and signed by the Italian President, for following our activities in Brazil where he is currently Ambassador of Italy. This year has been marked by an intense series of lectures organized by ICRANet at the University of Nice Sofia Antipolis for the graduate students and by the completion of the seat of Villa Ratti in Nice. We are grateful for this common effort to the President, Albert Marouani, and the Vice President, Pierre Coullet, of the University of Nice Sofia Antipolis. We are grateful to the Mayor of Pescara, Luigi Albore-Mascia, to the Mayor of Nice, Christian Estrosi, to the Adjunct for Science, Research and Culture, Dr. Agnes Rampal, and to the President of the Conseil Général des Alpes-Maritimes, Eric Ciotti, for their generous support in granting to ICRANet the logistics of the Centers in their respective townships. We are equally very grateful to the Brazilian Institutions, the Foreign Minister of Brazil, the Minister of Science of Brazil, the Governor of the State of Cearà, the Mayor of Rio for their essential support in the establishment of the ICRANet seat in Brazil. All this has been made possible thanks to the very effective presence of Mario Novello and Joao Braga in the board and in the Scientific Committee of ICRANet. A special sign of gratitude goes to Minister Roberto Amaral and to Prof. Francisco José Amaral Vieira for their continuous support. All this work could not have been achieved without the help of all Members institutions of ICRANet. Clearly, a special mention of satisfaction goes to all the Scientific Institutions and Research Centers which have signed with us a collaboration agreement which include BSU (Belarusian State University, Belarus), CBPF (Brazil), Cearà State (Brazil), ENEA (National Agency for new technologies, energy and the economic sustainable development, Italy), ICTP (The Abdus Salam International Center for Theoretical Physics, Italy), IHEP (China), INFN (National Institute for Nuclear Physics, Italy), ITA (Brazil) GARR (Italy), LeCosPa (Leung Center for Cosmology and Particle Astrophysics, Taiwan), NAS (National Academy of Science, Armenia), Nice University Sophia Antipolis (France), Pescara University “D’Annunzio” (Italy), Physics Department of University of Rome “Sapienza” (Italy), UERJ (Rio de Janeiro State University, Brazil). ICRANet, as sponsor of the IRAP-PhD program, expresses its gratitude to AEI – Albert Einstein Institute – Potsdam (Germany), Berlin Free University (Germany), CBPF – Brazilian Centre for Physics Research (Brazil), Ferrara University (Italy), Indian centre for space physics (India), Nice University Sophia Antipolis (France), Observatory of the Côte d'Azur (France), Rome University – “Sapienza” (Italy), Savoie University (France), Shanghai Astronomical Observatory (China), Stockholm University (Sweden), Tartu Observatory (Estonia), for their joint effort in creating and activating this first European Ph.D. program in Relativistic Astrophysics which has obtained the official recognition of the Erasmus Mundus program of the European Community. All these activities were achieved thanks to the dedicated work of Prof. Pascal Chardonnet. Finally, thanks goes to the Physics Department and to the Rector of the University of Rome “Sapienza” for all the collaboration in the teaching, in the electronic links and in the common research. A special mention of gratitude, of course, goes to the administrative, secretarial and technical staff of ICRANet and ICRA for their essential and efficient daily support. |