Results 81 to 90 of about 20,263 (249)
More on the Non‐Gaussianity of Perturbations in a Nonminimal Inflationary Model
Advances in High Energy Physics, Volume 2018, Issue 1, 2018., 2018 We study nonlinear cosmological perturbations and their possible non‐Gaussian character in an extended nonminimal inflation where gravity is coupled nonminimally to both the scalar field and its derivatives. By expansion of the action up to the third order, we focus on the nonlinearity and non‐Gaussianity of perturbations in comparison with recent ...
R. Shojaee +3 more
wiley +1 more source
Higgs boson induced reheating and ultraviolet frozen-in dark matter
Journal of High Energy Physics, 2023 A reheating phase in the early universe is an essential part of all inflationary models during which not only the Standard Model (SM) quanta are produced but it can also shed light on the production of dark matter.
Aqeel Ahmed +2 more
doaj +1 more source
Three-form multiplet and Inflation [PDF]
, 2014 Most successful models of inflation in supergravity have a shift symmetry for the inflaton and contain a stabilizer field coupled to the inflaton in a particular way.
Dudas, Emilian
core +1 more source
Species Scale and Primordial Gravitational Waves
Fortschritte der Physik, Volume 72, Issue 6, June 2024.Abstract The species scale is a field‐dependent UV cut‐off for any effective field theory weakly coupled to gravity. In this letter, it is shown that in the context of inflationary cosmology, a detection of primordial gravitational waves will set an upper bound on the decay rate |Λs′/Λs|$|\Lambda ^{\prime }_s/\Lambda _s|$ of the species scale ...
Marco Scalisi
wiley +1 more source
Constraints on Gravitation from Causality and Quantum Consistency
Advances in High Energy Physics, Volume 2018, Issue 1, 2018., 2018 We examine the role of consistency with causality and quantum mechanics in determining the properties of gravitation. We begin by examining two different classes of interacting theories of massless spin 2 particles—gravitons. One involves coupling the graviton with the lowest number of derivatives to matter, the other involves coupling the graviton ...
Mark P. Hertzberg +1 more
wiley +1 more source
Non-linear isocurvature perturbations and non-Gaussianities [PDF]
, 2008 We study non-linear primordial adiabatic and isocurvature perturbations and their non-Gaussianity. After giving a general formulation in the context of an extended delta N-formalism, we analyse in detail two illustrative examples.
Alabidi L +19 more
core +2 more sources
Astronomische Nachrichten, Volume 345, Issue 2-3, February-March 2024.Abstract This paper focuses on the implications of a commutative formulation that integrates branch‐cutting cosmology, the Wheeler–DeWitt equation, and Hořava–Lifshitz quantum gravity. Building on a mini‐superspace structure, we explore the impact of an inflaton‐type scalar field on the wave function of the Universe.
Fridolin Weber +8 more
wiley +1 more source
Inhomogeneous Extra Space as a Tool for the Top‐Down Approach
Advances in High Energy Physics, Volume 2018, Issue 1, 2018., 2018 The top‐down approach for the 6‐dimensional space has been elaborated. The connection between the cosmological constant and the extra space metric has been obtained. The metric can be found with the necessary accuracy. It is shown that descent from high energies to the low ones leads to the quantum corrections which influence weakly the metric of extra
Sergey G. Rubin, Elias C. Vagenas
wiley +1 more source
Non-thermal production of pNGB dark matter and inflation
Journal of High Energy Physics, 2021 A pseudo Nambu-Goldstone boson (pNGB) is a natural candidate of dark matter in that it avoids the severe direct detection bounds. We show in this paper that the pNGB has another different and interesting face with a higher symmetry breaking scale.
Yoshihiko Abe +2 more
doaj +1 more source
Proceedings of 7th Symposium on Prospects in the Physics of Discrete Symmetries, DISCRETE 2020-2021 — PoS(DISCRETE2020-2021), 2022 We discuss a minimal extension of the Standard Model (SM) where a single real scalar field serves as both inflaton and dark matter. The corresponding Lagrangian contains the renormalizable interactions of the inflaton field. Quantum effects generally induce a non-minimal coupling to gravity which facilitates inflation consistent with the PLANCK ...
openaire +3 more sources