Browsing by Author "Grammenos, T."
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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 and momentum distributions of the magnetic solution to (2+1) EinsteinMaxwell gravity
Grammenos, T. (2005)We use Moller's energymomentum complex in order to explicitly evaluate the energy and momentum density distributions associated with the threedimensional magnetic solution to the EinsteinMaxwell equations. The magnetic ... 
Energy distribution in a Schwarzschildlike spacetime
Grammenos, T.; Radinschi, I. (2007)In this paper, utilizing Moller's energymomentum complex, we explicitly evaluate the energy and momentum density associated with a metric describing a fourdimensional, Schwarzschildlike, spacetime derived from an effective ... 
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 ... 
Energy distribution of the EinsteinKleinGordon system for a static spherically symmetric spacetime in (2+1) dimensions
Radinschi, I.; Grammenos, T. (2006)We use Moller's energymomentum complex in order to explicitly compute the energy and momentum density distributions for an exact solution of Einstein's field equations with a negative cosmological constant, minimally ... 
ENERGY LOCALIZATION FOR DILATONIC BLACK HOLE GEOMETRIES WITH A PURE MONOPOLE FIELD
Radinschi, I.; Grammenos, T. (2010)The energy distribution of black holes with a dilaton and a pure monopole field is calculated by using Moller's energymomentum complex. The fourdimensional spacetimes considered are static, spherically symmetric and ... 
Energymomentum complexes for a stringy black hole geometry in a lowenergy effective string theory
Radinschi, I.; Grammenos, T. (2009)The energy and momentum distributions for a fourdimensional, magnetically charged, stringy black hole geometry, in a lowenergy effective string theory, are calculated. To this purpose, the energymomentum complexes of ... 
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, ... 
Fluid ordering effects and density variations in nanochannel flows: a quasicontinuum theory
Grammenos, T.; Giannakopoulos, A. (2014)A quasicontinuum selfdiffusion theory that can capture the fluid ordering effects and density variations predicted by nonequilibrium molecular dynamics in nanochannel flows is presented. The physics of the problem suggests ... 
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 ... 
Locally homogeneous spaces, induced Killing vector fields and applications to Bianchi prototypes
Papadopoulos, G. O.; Grammenos, T. (2012)An answer to the question: Can, in general, the adoption of a given symmetry induce a further symmetry, which might be hidden at a first level? has been attempted in the context of differential geometry of locally homogeneous ... 
Moller's energymomentum complex for a spacetime geometry on a noncommutative curved D3brane
Radinschi, I.; Grammenos, T. (2008)Moller's energymomentum complex is employed in order to determine the energy and momentum distributions for a spacetime described by a "generalized Schwarzschild" geometry in (3+1)dimensions on a noncommutative curved ... 
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 ...