Results 1 to 10 of about 1,515,012 (182)

Perfect Fluid Spacetimes and Gradient Solitons

Journal of Nonlinear Mathematical Physics, 2022
AbstractIn this article, we investigate perfect fluid spacetimes equipped with concircular vector field. At first, in a perfect fluid spacetime admitting concircular vector field, we prove that the velocity vector field annihilates the conformal curvature tensor.
Krishnendu De, Abdallah Syied
exaly   +5 more sources

Conformal Einstein Perfect Fluid Spacetimes [PDF]

Journal of Physics: Conference Series, 2011
A review is given of results obtained in connection with perfect fluid spacetimes which are conformally related to Einstein spaces.
Norbert Van den Bergh, Van den Bergh, Norbert   +1 more
exaly   +5 more sources

Perfect fluid spacetimes and $k$-almost Yamabe solitons

Turkish Journal of Mathematics, 2023
In this article, we presumed that a perfect fluid is the source of the gravitational field while analyzing the solutions to the Einstein field equations. With this new and creative approach, here we study $k$-almost Yamabe solitons and gradient $k$-almost Yamabe solitons.
Aydin Gezer, Uday Chand De
exaly   +5 more sources

Perfect Fluid Spacetimes Admitting Almost Riemann Solitons

Axioms
In this investigation, we examine the geometric character of almost Riemann solitons and gradient almost Riemann solitons in the context of perfect fluid solutions of the Einstein equations that admit a torse-forming vector field ζ.
Mehdi Jafari, Shahroud Azami
doaj   +4 more sources

Classification of LRS Bianchi-I spacetime in context of f(T) gravity via its self-similar symmetry. [PDF]

PLoS ONE
This study investigates self-similar vector fields of locally rotationally symmetric Bianchi type-I spacetimes within the framework of f(T) gravity, incorporating a perfect fluid as the matter source.
Rabeb Sidaoui, A H A Alfedeel, Jamshed Khan, Mohammed Alsharafi, E I Hassan, Khaled Aldwoah   +5 more
doaj   +2 more sources

Characterizations of generalized Robertson-Walker spacetimes concerning gradient solitons [PDF]

Heliyon
In this article, we examine gradient type Ricci solitons and (m,τ)-quasi Einstein solitons in generalized Robertson-Walker (GRW) spacetimes. Besides, we demonstrate that in this scenario the GRW spacetime presents the Robertson-Walker (RW) spacetime and ...
Krishnendu De, Mohammad Nazrul Islam Khan, Uday Chand De   +2 more
doaj   +2 more sources

Semiconformal curvature tensor and perfect fluid spacetimes in general relativity

Journal of Taibah University for Science, 2020
The semiconformal curvature tensor and its divergence have been studied for perfect fluid spacetimes. It is seen, apart from other results, that the perfect fluid spacetimes with divergence-free semiconformal curvature tensor either satisfy the vacuum ...
Musavvir Ali, Naeem Ahmad Pundeer, Akram Ali   +2 more
doaj   +2 more sources

Homothetic perfect fluid spacetimes [PDF]

Classical and Quantum Gravity, 1997
A brief summary of results on homotheties in General Relativity is given, including general information about space-times admitting an r-parameter group of homothetic transformations for r>2, as well as some specific results on perfect fluids. Attention is then focussed on inhomogeneous models, in particular on those with a homothetic group $H_4 ...
Alicia M Sintes, Jaume Carot
exaly   +4 more sources

Cosmological reconstruction and energy constraints in generalized Gauss–Bonnet-scalar–kinetic–matter couplings [PDF]

Scientific Reports, 2020
Recently introduced $$f(\mathcal {G},T)$$ f ( G , T ) theory is generalized by adding dependence on the arbitrary scalar field $$\phi $$ ϕ and its kinetic term $$(\nabla \phi )^2$$ ( ∇ ϕ ) 2 , to explore non-minimal interactions between geometry, scalar ...
Adam Z. Kaczmarek, Dominik Szczęśniak
doaj   +2 more sources

Collapsing perfect fluid in higher-dimensional spherical spacetimes [PDF]

Classical and Quantum Gravity, 2000
Class. Quantum Grav.
Anzhong Wang
exaly   +4 more sources