Results 31 to 40 of about 11,605 (193)
Bouncing Cosmology in f(G, T) Gravity with Logarithmic Trace Term
Advances in Astronomy, Volume 2021, Issue 1, 2021., 2021 This study is devoted to explore bouncing cosmology in the context of fG,T theory of gravity. For this purpose, a Gauss–Bonnet cosmological model with logarithmic trace term is considered. In particular, the possibility of obtaining bouncing solutions by considering two equations of state parameters is investigated. A graphical analysis is provided for
M. Farasat Shamir, Rafael Correa
wiley +1 more source
$$f(\mathcal {R},\varphi ,\chi )$$ f(R,φ,χ) cosmology with Noether symmetry
European Physical Journal C: Particles and Fields, 2020 This paper is devoted to explore modified $$f(\mathcal {R})$$ f(R) theories of gravity using Noether symmetry approach. For this purpose, Friedmann–Robertson–Walker spacetime is chosen to investigate the cosmic evolution. The study is mainly divided into
M. Farasat Shamir
doaj +1 more source
Physics Letters B, 2022 We present a cosmological model arising from a gravitational theory with an infinite tower of higher-order curvature invariants that can reproduce the entire evolution of the Universe: from inflation to late-time acceleration, without invoking an ...
Luisa G. Jaime, Gustavo Arciniega
doaj +1 more source
How Nonassociative Geometry Describes a Discrete Spacetime
Frontiers in Physics, 2019 Nonassociative geometry, providing a unified description of discrete and continuum spaces, is a valuable candidate for the study of discrete models of spacetime. Within the framework of nonassociative geometry we propose a model of emergent spacetime. In
Alexander I. Nesterov, Héctor Mata
doaj +1 more source
Holographic evolution with dynamical boundary gravity
Journal of High Energy Physics, 2022 Holography has provided valuable insights into the time evolution of strongly coupled gauge theories in a fixed spacetime. However, this framework is insufficient if this spacetime is dynamical.
Christian Ecker +3 more
doaj +1 more source
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
openaire +3 more sources
Axion particle production in a laser-induced dynamical spacetime
Physics Letters B, 2018 We consider the dynamics of a charged particle (e.g., an electron) oscillating in a laser field in flat spacetime and describe it in terms of the variable mass metric.
M.A. Wadud +3 more
doaj +1 more source
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.
openaire +3 more sources
Boson mixing and flavor vacuum in the expanding Universe: A possible candidate for the dark energy
Physics Letters B, 2023 We analyze the boson mixing in curved spacetime and compute the expectation value of the energy-momentum tensor of bosons on the flavor vacuum in spatially flat Friedmann-Lemaître-Robertson-Walker metrics.
Antonio Capolupo, Aniello Quaranta
doaj +1 more source
Dynamical wormholes in Einstein–Gauss–Bonnet gravity
European Physical Journal C: Particles and Fields, 2020 In the present work, we investigate evolving wormhole configurations in higher-dimensions, by adding a Gauss–Bonnet term to the standard Einstein–Hilbert action.
Mohammad Reza Mehdizadeh
doaj +1 more source