Results 1 to 10 of about 263 (151)
NONASSOCIATIVE GEOMETRY: FRIEDMANN–ROBERTSON–WALKER SPACETIME [PDF]
International Journal of Geometric Methods in Modern Physics, 2006 In (Phys. Rev. D62 (2000) 081501(R)) we proposed a unified description of continuum and discrete spacetime based on nonassociative geometry. It follows from our approach that at distances comparable with Planck length the standard concept of spacetime might be replaced by the nonassociative discrete structure, and nonassociativity is the algebraic ...
Alexander I Nesterov
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On the integrability of the geodesic flow on a Friedmann–Robertson–Walker spacetime [PDF]
Physica Scripta, 2018 We study the geodesic flow on the cotangent bundle of a Friedman-Robertson-Walker spacetime (M, g). On this bundle, the HamiltonJacobi equation is completely separable and this separability leads us to construct four linearly independent integrals in involution i.e. Poisson commuting amongst themselves and pointwise linearly independent.
Thomas Zinnias
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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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Uniqueness of self-similar asymptotically Friedmann-Robertson-Walker spacetime in Brans-Dicke theory [PDF]
Physical Review D, 2002 Revised version, 4 pages, no figures, Revtex, accepted for publication in Physical Review ...
Maeda, Hideki +2 more
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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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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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Boundary Value Problems, 2021 Consider nonlinear wave equations in the spatially flat Friedmann–Lemaître–Robertson–Walker (FLRW) spacetimes. We show blow-up in finite time of solutions and upper bounds of the lifespan of blow-up solutions to give the FLRW spacetime version of Glassey’
Kimitoshi Tsutaya, Yuta Wakasugi
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Estimation of temperature of cosmological apparent horizons: a new approach
European Physical Journal C: Particles and Fields, 2021 We consider radiation from cosmological apparent horizon in Friedmann–Lemaitre–Robertson–Walker (FLRW) model in a double-null coordinate setting. As the spacetime is dynamic, there is no timelike Killing vector, instead we have Kodama vector which acts ...
Bhramar Chatterjee, Narayan Banerjee
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Covariant Space-Time Line Elements in the Friedmann–Lemaitre–Robertson–Walker Geometry
Axioms, 2022 Most quantum gravity theories quantize space-time on the order of Planck length (ℓp ). Some of these theories, such as loop quantum gravity (LQG), predict that this discreetness could be manifested through Lorentz invariance violations (LIV) over ...
David Escors, Grazyna Kochan
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