Classical Aspects of General Relativity 
Participants:
Topics of research:The research concerning this topic is mostly devoted to the study of physical phenomena within a certain fixed frame of reference, in the framework of general relativity. Using systematically the so called "spacetime splitting techniques" in a fixed frame one reintroduces in the spacetime the ordinary and separated notions of space and time which are essential to any observer for his measurement process. On the other hand, the various splitting techniques find their natural positioning in the so called "gravitoelectromagnetism," i.e. a formal analogy which can be posed between gravity and electromagnetism. This, in fact, can be considered as the most suited language for the splitting of the spacetime itself, being clear enough, accessible and expressive; moreover, it can be used to create a novel standard terminology with the advantage of esily connect among the different schools of relativity which for a long period have worked in complete insulation. One may say that a splitting of specetime is not necessary at all, being the unification of space and time the most important result of relativity and that passing from the 4dimensional point of view to the 1+3 one means abandoning the elegance of the 4geometry towards a more physical approach. However, the necessity of the splitting is evident in many applications. For instance it is useful when the spacetime is endowed with special symmetries, as in the case of stationary spacetimes (including black hole spacetimes) or homogeneous spacetimes (of interest in cosmology). This summarizes our main motivation for this kind of study. We have published a number of applications concerning test particle motion, spinning particles and fluids. At the moment we are considering applications to the case of fields on a fixed gravitational background also at the quantum level.
