Zobrazeno 1 - 10
of 29
pro vyhledávání: '"Pelavas, Nicos"'
Publikováno v:
IJGMMP, 7, 1349, 2010
We study the existence of a non-spacelike isometry, \zeta, in higher dimensional Kundt spacetimes with constant scalar curvature invariants (CSI). We present the particular forms for the null or timelike Killing vectors and a set of constraints for t
Externí odkaz:
http://arxiv.org/abs/1210.7365
Publikováno v:
IJGMMP, 6, 419, 2009
We study the class of higher-dimensional Kundt metrics admitting a covariantly constant null vector, known as CCNV spacetimes. We pay particular attention to those CCNV spacetimes with constant (polynomial) curvature invariants (CSI). We investigate
Externí odkaz:
http://arxiv.org/abs/1210.7364
Publikováno v:
Class.Quant.Grav.27:102001,2010
We discuss (arbitrary-dimensional) Lorentzian manifolds and the scalar polynomial curvature invariants constructed from the Riemann tensor and its covariant derivatives. Recently, we have shown that in four dimensions a Lorentzian spacetime metric is
Externí odkaz:
http://arxiv.org/abs/1003.2373
Publikováno v:
Class.Quant.Grav.26:125011,2009
In this paper we investigate four dimensional Lorentzian spacetimes with constant curvature invariants ($CSI$ spacetimes). We prove that if a four dimensional spacetime is $CSI$, then either the spacetime is locally homogeneous or the spacetime is a
Externí odkaz:
http://arxiv.org/abs/0904.4877
Publikováno v:
Class.Quant.Grav.26:025013,2009
In this paper we determine the class of four-dimensional Lorentzian manifolds that can be completely characterized by the scalar polynomial curvature invariants constructed from the Riemann tensor and its covariant derivatives. We introduce the notio
Externí odkaz:
http://arxiv.org/abs/0901.0791
Autor:
Milson, Robert, Pelavas, Nicos
We prove that a four-dimensional Lorentzian manifold that is curvature homogeneous of order 3, or CH_3 for short, is necessarily locally homogeneous. We also exhibit and classify four-dimensional Lorentzian, CH_2 manifolds that are not homogeneous. T
Externí odkaz:
http://arxiv.org/abs/0711.3851
Publikováno v:
Class.Quant.Grav.25:025008,2008
In this paper we study Lorentzian spacetimes for which all polynomial scalar invariants constructed from the Riemann tensor and its covariant derivatives are constant (CSI spacetimes) in three dimensions. We determine all such CSI metrics explicitly,
Externí odkaz:
http://arxiv.org/abs/0710.3903
Autor:
Milson, Robert, Pelavas, Nicos
Publikováno v:
Class.Quant.Grav.25:012001,2008
We present a family of four-dimensional Lorentzian manifolds whose invariant classification requires the seventh covariant derivative of the curvature tensor. The spacetimes in questions are null radiation, type N solutions on an anti-de Sitter backg
Externí odkaz:
http://arxiv.org/abs/0710.0688
Publikováno v:
Class.Quant.Grav.23:3053-3074,2006
We study Lorentzian spacetimes for which all scalar invariants constructed from the Riemann tensor and its covariant derivatives are constant ($CSI$ spacetimes). We obtain a number of general results in arbitrary dimensions. We study and construct wa
Externí odkaz:
http://arxiv.org/abs/gr-qc/0509113
Autor:
Pelavas, Nicos, Coley, Alan
Publikováno v:
Int.J.Theor.Phys. 45 (2006) 1258-1266
We discuss whether an appropriately defined dimensionless scalar function might be an acceptable candidate for the gravitational entropy, by explicitly considering Szekeres and Bianchi type VI$_{h}$ models that admit an isotropic singularity. We also
Externí odkaz:
http://arxiv.org/abs/gr-qc/0410008