Results 41 to 50 of about 131,283 (219)
Stress–energy connection and cosmological constant problem [PDF]
Physics Letters B, 2011 We study gravitational properties of vacuum energy by erecting a geometry on the stress-energy tensor of vacuum, matter and radiation. Postulating that the gravitational effects of matter and radiation can be formulated by an appropriate modification of the spacetime connection, we obtain varied geometro-dynamical equations which properly comprise the ...
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Physics Letters BThe (old) cosmological constant problem consists of two different problems. The first is the huge discrepancy between the value of the cosmological constant deduced from observations and its value expected from cosmological constant-like theoretical ...
Recai Erdem
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Semi-classical gravity in de Sitter spacetime and the cosmological constant
Physics Letters B, 2019 We show that there exist solutions to the semi-classical gravity equations in de Sitter spacetime sourced by the renormalised stress-energy tensor of a free Klein-Gordon field.
Benito A. Juárez-Aubry
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Revising the cosmological constant problem through a fluid different from the quintessence
Physical Sciences and Technology, 2022 The role of a scalar field is reexamined through the introduction of a quasi-quintessence model. Unlike quintessence, in the quasi-quintessence model, the pressure of the scalar field does not depend on its kinetic energy. This research note provides an
Orlando Luongo
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Über-gravity and the cosmological constant problem [PDF]
Physics of the Dark Universe, 2018 Recently, the idea of taking ensemble average over gravity models has been introduced. Based on this idea, we study the ensemble average over (effectively) all the gravity models (constructed from Ricci scalar) dubbing the name ber-gravity which is a {\it{fixed point}} in the model space.
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Quantum Theory, Noncommutative Gravity, and the Cosmological Constant Problem
Advances in Astronomy, 2009 The cosmological constant problem is principally concerned with trying to understand how the zero-point energy of quantum fields contributes to gravity. Here we take the approach that by addressing a fundamental unresolved issue in quantum theory, we can
T. P. Singh
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Cosmological model from the holographic equipartition law with a modified Rényi entropy
European Physical Journal C: Particles and Fields, 2017 Cosmological equations were recently derived by Padmanabhan from the expansion of cosmic space due to the difference between the degrees of freedom on the surface and in the bulk in a region of space. In this study, a modified Rényi entropy is applied to
Nobuyoshi Komatsu
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Environmental selection of the cosmological constant and electroweak scales
Journal of High Energy Physics, 2022 We investigate whether selfish/Goldilocks Higgs models can be extended to accomodate vacua with both the right Higgs mass and cosmological constant. Through the introduction of multiple four-form fields coupled with the Higgs scalar boson we find that ...
Matteo Moretti, Francisco G. Pedro
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Open Inflation, the Four Form and the Cosmological Constant [PDF]
, 1998 Fundamental theories of quantum gravity such as supergravity include a four form field strength which contributes to the cosmological constant. The inclusion of such a field into our theory of open inflation (hep-th/9802030) allows an anthropic solution ...
Coleman +10 more
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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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