Results 31 to 40 of about 613 (177)
The Vacuum State of Primordial Fluctuations in Hybrid Loop Quantum Cosmology
Universe, 2018 We investigate the role played by the vacuum of the primordial fluctuations in hybrid Loop Quantum Cosmology. We consider scenarios where the inflaton potential is a mass term and the unperturbed quantum geometry is governed by the effective dynamics of ...
Beatriz Elizaga Navascués +2 more
doaj +1 more source
Group Field Theory and Its Cosmology in a Matter Reference Frame
Universe, 2018 While the equations of general relativity take the same form in any coordinate system, choosing a suitable set of coordinates is essential in any practical application.
Steffen Gielen
doaj +1 more source
Aspects of Quantum Theory in General Relativity and Cosmology
, 2020 After a brief introduction to Cosmology some quantum aspects of General Relativity and cosmology are presented. The radial motion of a massive particles in the ergosphere of the Kerr Black Hole is considered. Screening of Hawking radiation and shielding of the Penrose process is examined in the context of the region of negative energy inside the ...
openaire +2 more sources
Shedding light on gravity: Black hole shadows and lensing signatures in Lorentz gauge theory
Nuclear Physics BRecent advances, including gravitational wave detections and imaging of black hole shadows, have strongly validated general relativity. Nevertheless, ongoing cosmological observations suggest potential limitations of general relativity, spurring interest
Ali Övgün, Mohsen Fathi
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European Physical Journal C: Particles and Fields, 2022 We consider some background tests of standard cosmology in the context of Hořava gravity with different scaling dimensions for space and time, which has been proposed as a renormalizable, higher-derivative, Lorentz-violating quantum gravity model without
Nils A. Nilsson, Mu-In Park
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Effective f(R) Actions for Modified Loop Quantum Cosmologies via Order Reduction
Universe, 2023 General Relativity is an extremely successful theory, at least for weak gravitational fields; however, it breaks down at very high energies, such as in correspondence to the initial singularity.
Ana Rita Ribeiro +2 more
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European Physical Journal C: Particles and Fields, 2018 Bouncing cosmologies are obtained by adding to the Einstein–Hilbert action a term of the form $$\sqrt{-\,g}f(\chi )$$ -gf(χ) , with $$\chi $$ χ a scalar depending on the Hubble parameter only, not on its derivatives, and which is here shown to arise from
Jaume de Haro +2 more
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Non-metricity signatures on the Higgs boson signal strengths at the LHC
Journal of High Energy Physics, 2022 In this work we study the high-energy Higgs boson phenomenology associated to the non-metricity scale Λ Q at the LHC. Non-metricity is present in more generic non-Riemannian geometries describing gravity beyond General Relativity and exhibits nice ...
Victor Ilisie
doaj +1 more source
Effective actions for loop quantum cosmology in fourth-order gravity
European Physical Journal C: Particles and Fields, 2021 Loop quantum cosmology (LQC) is a theory which renders the Big Bang initial singularity into a quantum bounce, by means of short-range repulsive quantum effects at the Planck scale.
Marcello Miranda +3 more
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Spatial Statistics for Screening Molecular Structures
Small, EarlyView.Deep architectures for materials discovery demand vast training data and obscure the structure‐property link. This review shows how spatial statistics offer a physically grounded alternative: voxelized fields and two‐point correlations, compressed by principal component analysis, yield convex, interpretable descriptors. Lean surrogates then reach sub‐2%
Pranoy Ray, Surya R. Kalidindi
wiley +1 more source