8 research outputs found
Ultimate gravitational mass defect
We present a new type of gravitational mass defect in which an infinite
amount of matter may be bounded in a zero ADM mass. This interpolates between
effects typical of closed worlds and T-spheres. We consider the Tolman model of
dust distribution and show that this phenomenon reveals itself for a solution
that has no origin on one side but is closed on the other side. The second
class of examples corresponds to smooth gluing T-spheres to the portion of the
Friedmann-Robertson-Walker solution. The procedure is generalized to
combinations of smoothly connected T-spheres, FRW and Schwarzschild metrics. In
particular, in this approach a finite T-sphere is obtained that looks for
observers in two R-regions as the Schwarzschild metric with two different
masses one of which may vanish.Comment: 9 pages. 1 reference added. To appear in Gen. Rel. Gra
The averaged tensors of the relative energy-momentum and angular momentum in general relativity and some their applications
There exist at least a few different kind of averaging of the differences of
the energy-momentum and angular momentum in normal coordinates {\bf NC(P)}
which give tensorial quantities. The obtained averaged quantities are
equivalent mathematically because they differ only by constant scalar
dimensional factors. One of these averaging was used in our papers [1-8] giving
the {\it canonical superenergy and angular supermomentum tensors}.
In this paper we present another averaging of the differences of the
energy-momentum and angular momentum which gives tensorial quantities with
proper dimensions of the energy-momentum and angular momentum densities. But
these averaged relative energy-momentum and angular momentum tensors, closely
related to the canonical superenergy and angular supermomentum tensors, {\it
depend on some fundamental length }.
The averaged relative energy-momentum and angular momentum tensors of the
gravitational field obtained in the paper can be applied, like the canonical
superenergy and angular supermomentum tensors, to {\it coordinate independent}
analysis (local and in special cases also global) of this field.
We have applied the averaged relative energy-momentum tensors to analyze
vacuum gravitational energy and momentum and to analyze energy and momentum of
the Friedman (and also more general) universes. The obtained results are very
interesting, e.g., the averaged relative energy density is {\it positive
definite} for the all Friedman universes.Comment: 30 pages, minor changes referring to Kasner universe
Energy Momentum of Marder Universe in Teleparallel gravity
This paper has been removed by arXiv administrators because of overlap with
gr-qc/0408043 and 0706.3245.
This paper has excessive overlap with the following papers also written by
the authors or their collaborators: gr-qc/0607110, gr-qc/0607126,
gr-qc/0608024, gr-qc/0603044, gr-qc/0505078, gr-qc/0502042, gr-qc/0502031,
gr-qc/0606028, gr-qc/0508018, gr-qc/0511095, and others.Comment: This submission has been withdrawn by arXiv administrators due to
inappropriate text reuse from external source