Results 11 to 20 of about 6,253,661 (292)
Reconstruction of cosmological models are inspired by generalization of the Chaplygin gas
Қарағанды университетінің хабаршысы. Физика сериясы, 2022 This paper considers models arising from the composition of the modified Gauss–Bonnet gravity (the Gauss–Bonnet invariant) and the general relativity (the Ricci scalar) against the background of a flat, homogeneous, and isotropic space-time described by
П.Ю. Цыба +2 more
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Energy conditions and junction conditions [PDF]
Physical Review D, 2005 10 pages; v2: minor corrections, brief comments on negative energy spacetimes in sec.4 ...
Marolf, Donald, Yaida, Sho
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High-temperature superconductor of sodalite-like clathrate hafnium hexahydride
Scientific Reports, 2021 Hafnium hydrogen compounds have recently become the vibrant materials for structural prediction at high pressure, from their high potential candidate for high-temperature superconductors.
Prutthipong Tsuppayakorn-aek +3 more
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Bouncing Cosmology in Modified Gravity with Higher-Order Gauss–Bonnet Curvature Term
Universe, 2022 In this paper, we studied the bouncing behavior of the cosmological models formulated in the background of the Hubble function in the F(R,G) theory of gravity, where R and G, respectively, denote the Ricci scalar and Gauss–Bonnet invariant.
Santosh V. Lohakare +3 more
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Damour–Solodukhin Wormhole as a Black Hole Mimicker: The Role of Observers’ Location
Universe, 2022 It has been recently argued that in semi-classical gravity, a minimal 2-sphere is not a horizon but a tiny throat of a wormhole, such as the Damour–Solodukhin wormhole (DSWH), with a free parameter λ≠0 separating it from a Schwarxzschild black hole (BH) (
Kamal K. Nandi +3 more
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NULL ENERGY CONDITION AND DARK ENERGY MODELS [PDF]
Modern Physics Letters A, 2008 Null Energy Condition (NEC) requires the equation of state (EoS) of the universe wu satisfy wu ≥ -1, which implies, for instance in a universe with matter and dark energy dominating wu = w m Ω m + w de Ω de = w de Ω de ≥ -1. In this paper we study constraints on the dark energy models from the requirement of the NEC.
Qiu, Taotao, Cai, Yi-Fu, Zhang, Xin-Min
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Almost-Pseudo-Ricci Symmetric FRW Universe with a Dynamic Cosmological Term and Equation of State
Universe, 2021 The objective of the present paper is to investigate an almost-pseudo-Ricci symmetric FRW spacetime with a constant Ricci scalar in a dynamic cosmological term Λ(t) and equation of state (EoS) ω(t) scenario. Several cosmological parameters are calculated
Sanjay Mandal +3 more
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The Smeared Null Energy Condition [PDF]
Journal of High Energy Physics, 2018 Abstract We propose a new bound on a weighted average of the null energy along a finite portion of a null geodesic: the Smeared Null Energy Condition (SNEC). We believe our bound is valid on scales small compared to the radius of curvature in any quantum field theory that is consistently coupled to gravity.
Freivogel, B., Krommydas, D.
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Scientific Reports, 2021 Regarded as doped binary hydrides, ternary hydrides have recently become the subject of investigation since they are deemed to be metallic under pressure and possibly potentially high-temperature superconductors.
Prutthipong Tsuppayakorn-aek +4 more
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Observational Constraints and Some Toy Models in f(Q) Gravity with Bulk Viscous Fluid
Universe, 2022 The standard formulation of general relativity fails to describe some recent interests in the universe. It impels us to go beyond the standard formulation of gravity.
Sanjay Mandal +2 more
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