38 research outputs found
Large quantum gravity effects and nonlocal variables
We reconsider here the model where large quantum gravity effects were first
found, but now in its Null Surface Formulation (NSF). We find that although the
set of coherent states for , the basic variable of NSF, is as restricted as
it is the one for the metric, while some type of small deviations from these
states may cause huge fluctuations on the metric, the corresponding
fluctuations on remain small.Comment: 4 pages, accepted in PR
Smooth null hypersurfaces near the horizon in the presence of tails
We show that the power-law decay modes found in linear perturbations of
Schwarzschild black holes, generally called tails, do not produce caustics on a
naturally defined family of null surfaces in the neighborhood of i+ of a black
hole horizon
Electromagnetic Induced Gravitational Perturbations
We study the physical consequences of two diffferent but closely related
perturbation schemes applied to the Einstein-Maxwell equations. In one case the
starting space-time is flat while in the other case it is Schwarzschild. In
both cases the perturbation is due to a combined electric and magnetic dipole
field. We can see, within the Einstein-Maxwell equations a variety of physical
consequences. They range from induced gravitational energy-momentum loss, to a
well defined spin angular momentum with its loss and a center-of-mass with its
equations of motion.Comment: 1
CR Structures and Asymptotically Flat Space-Times
We discuss the unique existence, arising by analogy to that in algebraically
special space-times, of a CR structure realized on null infinity for any
asymptotically flat Einstein or Einstein-Maxwell space-time.Comment: 6 page
Understanding singularities in Cartan's and NSF geometric structures
In this work we establish a relationship between Cartan's geometric approach
to third order ODEs and the 3-dim Null Surface Formulation (NSF). We then
generalize both constructions to allow for caustics and singularities that
necessarily arise in these formalisms.Comment: 22 pages, 2 figure