Results 41 to 50 of about 202,532 (277)
Scientific ReportsIn this article, we explicitly construct the coordinates associated with the Penrose diagram in spacetimes connected via a spacelike thin shell in the following two examples: the generalized black-to-white hole bounce with mass difference and the ...
Wei-Chen Lin +2 more
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Running cosmological constant with observational tests
Physics Letters B, 2016 We investigate the running cosmological constant model with dark energy linearly proportional to the Hubble parameter, Λ=σH+Λ0, in which the ΛCDM limit is recovered by taking σ=0. We derive the linear perturbation equations of gravity under the Friedmann–
Chao-Qiang Geng +2 more
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Kac-Moody algebras and the cosmological constant
Physics Letters B, 2020 We show that the theory of gravity constructed from the non-linear realisation of the semi-direct product of the Kac-Moody algebra A1+++ with its vector representation does not allow a cosmological constant.
Peter West
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Transient Antiskyrmion‐Mediated Topological Transitions in Isotropic Magnets
Advanced Science, EarlyView.A transient antiskyrmion‐mediated pathway that drives repeated stripe‐to‐skyrmion transitions is revealed, producing a net increase in topological charge in isotropic Dzyaloshinskii–Moriya interaction films. Experiments and simulations identify the antiskyrmion as a metastable excitation, enabling stochastic bitstream generation for probabilistic ...
Bingqian Dai +18 more
wiley +1 more source
‘Turkeys Cannot Vote for Christmas’: Why Epistemic Disobedience in an Anti‐Black World Matters
Australian Journal of Social Issues, EarlyView.ABSTRACT Never in the history of global coloniality has the idea of epistemic disobedience been as important as in the 21st century. This is not only because the struggle for decolonisation has shifted from physical confrontation between the coloniser and the colonised into a battle of ideas but also because the former has deployed the idea of ...
Morgan Ndlovu
wiley +1 more source
Cosmological constant as an integration constant
European Physical Journal C: Particles and FieldsThe discrepancy between the observed value of the cosmological constant (CC) and its expected value from quantum field theoretical considerations motivates the search for a theory in which the CC is decoupled from the vacuum energy.
Justin C. Feng, Pisin Chen
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Fixing cosmological constant on the event horizon
European Physical Journal C: Particles and Fields, 2022 Standard cosmological equations are written for the Hubble volume, while the real boundary of space-time is the event horizon. Within the unimodular and thermodynamic approaches to gravity, the dark energy term in cosmological equations appears as an ...
Merab Gogberashvili
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Vacuum Energy, the Casimir Effect, and Newton’s Non-Constant
Universe, 2023 The idea of quantum mechanical vacuum energy contributing to the cosmological vacuum energy density is not new. However, despite the persisting cosmological constant problem, few investigations have focused on this subject.
Benjamin Koch +3 more
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Cosmological Bounce and the Cosmological Constant Problem
SSRN Electronic Journal, 2022 32 pages, 9 ...
Pavlović, Petar, Sossich, Marko
openaire +3 more sources
Quintessence and the cosmological constant
, 2002 Quintessence -- the energy density of a slowly evolving scalar field -- may constitute a dynamical form of the homogeneous dark energy in the universe. We review the basic idea in the light of the cosmological constant problem.
Abbott +38 more
core +2 more sources