Probing spatial orientability of a Friedmann-Robertson-Walker spatially flat spacetime
Physical Review D, 2022 One important global topological property of a spacetime manifold is orientability. It is widely believed that spatial orientability can only be tested by global journeys around the Universe to check for orientation-reversing closed paths. Since such global journeys are not feasible, theoretical arguments that combine universality of physical ...
Marcelo J Reboucas
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Emergence of space and spacetime dynamics of Friedmann-Robertson-Walker universe [PDF]
Journal of High Energy Physics, 2012 In a recent paper [arXiv:1206.4916] by T. Padmanabhan, it was argued that our universe provides an ideal setup to stress the issue that cosmic space is emergent as cosmic time progresses and that the expansion of the universe is due to the difference between the number of degrees of freedom on a holographic surface and the one in the emerged bulk.
R. Cai
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Fundamental solutions of the Dirac operator in the Friedmann–Lemaître–Robertson–Walker spacetime [PDF]
Annals of Physics, 2020 The equation of the spin-$\frac{1}{2}$ particles in the Friedmann-Lemaitre-Robertson-Walker spacetime is investigated. The retarded and advanced fundamental solutions to the Dirac operator and generalized Dirac operator as well as the fundamental ...
Karen Yagdjian
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Electronic Journal of Qualitative Theory of Differential EquationsIn this paper, we consider the radially symmetric spacelike solutions of a nonlinear Dirichlet problem for the prescribed mean curvature spacelike equation in a Friedmann–Lemaître–Robertson–Walker spacetime.
Ting Wang, Man Xu
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Ricci collineations in Friedmann–Robertson–Walker spacetimes [PDF]
Classical and Quantum Gravity, 2002 14 pages, plain TeX, no ...
Barnes, A, Camci, U
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Approximate KMS States for Scalar and Spinor Fields in Friedmann–Robertson–Walker Spacetimes [PDF]
Annales Henri Poincaré, 2011 We construct and discuss Hadamard states for both scalar and Dirac spinor fields in a large class of spatially flat Friedmann-Robertson-Walker spacetimes characterised by an initial phase either of exponential or of power-law expansion. The states we obtain can be interpreted as being in thermal equilibrium at the time when the scale factor a has a ...
C. DAPPIAGGI +2 more
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Equilibration and freeze-out of an expanding gas in a transport approach in a Friedmann–Robertson–Walker metric [PDF]
Physics Letters B, 2017 Motivated by a recent finding of an exact solution of the relativistic Boltzmann equation in a Friedmann–Robertson–Walker spacetime, we implement this metric into the newly developed transport approach Simulating Many Accelerated Strongly-interacting ...
J. Tindall +3 more
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Blow-up of solutions of semilinear wave equations in accelerated expanding Friedmann–Lemaître–Robertson–Walker spacetime [PDF]
Reviews in Mathematical Physics, 2021 Consider a nonlinear wave equation for a massless scalar field with self-interaction in the spatially flat Friedmann–Lemaître–Robertson–Walker spacetimes.
K. Tsutaya, Yuta Wakasugi
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Painlevé Analysis of the Cosmological Field Equations in Weyl Integrable Spacetime
Universe, 2022 We apply a singularity analysis to investigate the integrability properties of the gravitational field equations in Weyl Integrable Spacetime for a spatially flat Friedmann–Lemaître–Robertson–Walker background spacetime induced by an ideal gas.
Andronikos Paliathanasis
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Nonsingular Bouncing Model in Closed and Open Universe
Physical Sciences Forum, 2023 We investigate the background dynamics of a class of models with noncanonical scalar field and matter both in Friedmann Lemaitre Robertson Walker (FLRW) closed and open spacetime.
Manabendra Sharma +2 more
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