Zobrazeno 1 - 10
of 302
pro vyhledávání: '"Panotopoulos, G."'
We investigate the structure and radial oscillations of anisotropic compact stars composed of dark energy, using the vanishing complexity factor formalism within general relativity. This novel approach establishes a direct link between the energy den
Externí odkaz:
http://arxiv.org/abs/2407.17335
We investigate two novel models of charged black holes in the framework of non-linear electrodynamics of Born-Infeld type. In particular, starting from two concrete Lagrangian densities, the corresponding metric potentials, the electric field, the Sm
Externí odkaz:
http://arxiv.org/abs/2304.09777
We study dynamical dark energy models within Einstein's theory by means of matter perturbations and the growth index $\gamma$. Within four-dimensional General Relativity, we assume that dark energy does not cluster, and we adopt a linear ansatz for t
Externí odkaz:
http://arxiv.org/abs/2303.09492
Publikováno v:
Eur. Phys. J. C (2023) 83: 116
We investigate exotic stars composed of dark energy within the context of Einstein's General Relativity, by applying an extended Chaplygin gas equation-of-state. To account for anisotropies, we utilize a formalism based on the complexity factor to ob
Externí odkaz:
http://arxiv.org/abs/2302.00125
Publikováno v:
Annals of Physics 432 (2021) 168567
In this work, motivated by the fact that higher-dimensional theories predict the existence of black holes which differ from their four-dimensional counterpart, we analyse the geodesics and black hole shadow cast by a general non-extremal five-dimensi
Externí odkaz:
http://arxiv.org/abs/2010.03734
We study radial oscillations of non-rotating neutron stars (NSs) in four-dimensional General Relativity. The interior of the NS was modelled within a recently proposed multicomponent realistic equation of state (EoS) with the induced surface tension
Externí odkaz:
http://arxiv.org/abs/2002.12209
Publikováno v:
Eur. Phys. J. C (2019) 79: 802
In this work, starting from a spherically symmetric polytropic black hole, a rotating solution is obtained by following the Newman--Janis algorithm without complexification. Besides studying the horizon, the static conditions and causality issues of
Externí odkaz:
http://arxiv.org/abs/1905.11443
Autor:
Panotopoulos, G.
We give a scalar field description of two dark energy parameterizations, and we analyze in detail its cosmology both at the level of background evolution and at the level of linear perturbations. In particular, we compute the statefinder parameters a
Externí odkaz:
http://arxiv.org/abs/1706.10211
Publikováno v:
JHEP 1009:098,2010
We compute the absorption cross section of space-time scalars on a static D2 rane, in global coordinates, wrapped on the S^2 of an AdS_2 X S^2 X CY_3 geometry. We discuss its relevance for the construction of the dual quantum mechanics of Calabi-Yau
Externí odkaz:
http://arxiv.org/abs/0901.1180
Autor:
Panotopoulos, G.
In the present work we study a dark energy model in which a non-linear scalar field (tachyon) with a Born-Infeld type of action is responsible for the observed cosmic acceleration. The potential of the tachyon is well-motivated since it comes from op
Externí odkaz:
http://arxiv.org/abs/astro-ph/0606249