Browsing by Author "Spanou, A."
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Canonical quantization of some midisuperspace models in 2+1 and 3+1 dimensions
Christodoulakis, T.; Doulis, G.; Terzis, P. A.; Melas, E.; Grammenos, Th; Papadopoulos, G. O.; Spanou, A. (2009)A proposal is put forward which enables the canonical quantization of a family of axially symmetric geometries in 2+1 dimensions and a corresponding spherically symmetric family in 3+1 dimensions. The proposal consists of ... 
Canonical quantization of some midisuperspace models in 3+1 dimensions
Christodoulakis, T.; Doulis, G.; Terzis, P. A.; Melas, E.; Grammenos, Th; Papadopoulos, O.; Spanou, A. (2010)A proposal is put forward which enables the canonical quantization of a family of spherically symmetric geometries in 3+1 dimensions. The proposal consists of a particular renormalization Assumption and an accompanying ... 
Canonical quantization of static spherically symmetric geometries
Christodoulakis, T.; Dimakis, N.; Terzis, P. A.; Doulis, G.; Grammenos, Th; Melas, E.; Spanou, A. (2013)The conditional symmetries of the reduced EinsteinHilbert action emerging from a static, spherically symmetric geometry are used as supplementary conditions on the wave function. Based on their integrability conditions, ... 
Conditional symmetries and the canonical quantization of constrained minisuperspace actions: The Schwarzschild case
Christodoulakis, T.; Dimakis, N.; Terzis, P. A.; Doulis, G.; Grammenos, T.; Melas, E.; Spanou, A. (2013)A conditional symmetry is defined, in the phase space of a quadratic in velocities constrained action, as a simultaneous. conformal symmetry of the supermetric and the superpotential. Iris proven that such a symmetry ... 
Decoupling of the general scalar field mode and the solution space for Bianchi type I and V cosmologies coupled to perfect fluid sources
Christodoulakis, T.; Grammenos, T.; Helias, C.; Kevrekidis, P. G.; Spanou, A. (2006)The scalar field degree of freedom in Einstein's plus matter field equations is decoupled for Bianchi type I and V general cosmological models. The source, apart from the minimally coupled scalar field with arbitrary ... 
Distribution of EnergyMomentum in a SchwarzschildQuintessence SpaceTime Geometry
Radinschi, I.; Grammenos, T.; Spanou, A. (2013)An analysis of the energymomentum localization for a fourdimensional Schwarzschild black hole surrounded by dark energy in the form of quintessence is presented in order to provide expressions for the distributions of ... 
Energy Distribution of a Regular Black Hole Solution in EinsteinNonlinear Electrodynamics
Radinschi, I.; Rahaman, F.; Grammenos, T.; Spanou, A.; Islam, S. (2015)A study about the energy momentum of a new fourdimensional spherically symmetric, static and charged, regular black hole solution developed in the context of general relativity coupled to nonlinear electrodynamics is ... 
EnergyMomentum Localization for a SpaceTime Geometry Exterior to a Black Hole in the Brane World
Radinschi, I.; Grammenos, T.; Spanou, A. (2013)In general relativity one of the most fundamental issues consists in defining a generally acceptable definition for the energymomentum density. As a consequence, many coordinatedependent definitions have been presented, ... 
Localization of energy for a regular black hole solution in an asymptotically de Sitter spacetime geometry
Radinschi, I.; Grammenos, T.; Spanou, A. (2011)The energy and momentum distributions of a regular black hole in a fourdimensional, asymptotically de Sitter spacetime geometry are computed, whereby the Einstein, LandauLifshitz, Weinberg and Moller energymomentum ... 
Towards canonical quantum gravity for 3+1 geometries admitting maximally symmetric twodimensional surfaces
Christodoulakis, T.; Doulis, G.; Terzis, P. A.; Melas, E.; Grammenos, T.; Papadopoulos, G. O.; Spanou, A. (2010)The canonical decomposition of all 3+1 geometries admitting twodimensional spacelike surfaces is exhibited as a generalization of a previous work. A proposal, consisting of a specific renormalization Assumption and an ... 
Towards canonical quantum gravity for G(1) geometries in 2+1 dimensions with Lambdaterm
Christodoulakis, T.; Doulis, G.; Terzis, P. A.; Melas, E.; Grammenos, T.; Papadopoulos, G. O.; Spanou, A. (2008)The canonical analysis and subsequent quantization of the (2+1)dimensional action of pure gravity plus a cosmological constant term is considered, under the assumption of the existence of one spacelike Killing vector ...