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Related papers: Analytic Approximations for Fermionic Preheating

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We study the original $\alpha$-Fermi-Pasta-Ulam (FPU) system with $N=16,32$ and $64$ masses connected by a nonlinear quadratic spring. Our approach is based on resonant wave-wave interaction theory, i.e. we assume that, in the weakly…

Chaotic Dynamics · Physics 2020-06-05 Miguel Onorato , Lara Vozella , Davide Proment , Yuri V. Lvov

A coordinate system is constructed for a general accelerating observer in 1+1 dimensions, and is used to determine the particle density of the massless Dirac vacuum for that observer. Equations are obtained for the spatial distribution and…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Carl E. Dolby , Mark D. Goodsell , Stephen F. Gull

We consider a massless minimally coupled self interacting quantum scalar field coupled to fermion via the Yukawa interaction, in the inflationary de Sitter background. The fermion is also taken to be massless and the scalar potential is…

High Energy Physics - Theory · Physics 2024-01-03 Sourav Bhattacharya , Moutushi Dutta Choudhury

We examine models of fermions with infinite-range interactions which realize non-Fermi liquids with a continuously variable U(1) charge density $\mathcal{Q}$, and a non-zero entropy density $\mathcal{S}$ at vanishing temperature. Real time…

High Energy Physics - Theory · Physics 2015-11-18 Subir Sachdev

Remarkably, if $CP$ was spontaneously broken in the physics of inflation, fermions would notice and remember it. Based on that, we present a new (non-thermal) mechanism for generating self-interacting dark Dirac fermions prior to the Hot…

High Energy Physics - Theory · Physics 2020-08-26 Azadeh Maleknejad

We analyze an inflationary model in which part of the power in density perturbations arises due to particle production. The amount of particle production is modulated by an auxiliary field. Given an initial gradient for the auxiliary field,…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Guido D'Amico , Roberto Gobbetti , Matthew Kleban , Marjorie Schillo

We study thermal corrections to a model of real scalar dark matter (DM) interacting feebly with a SM fermion and a gauge-charged vector-like fermion mediator. We employ the Closed-Time-Path (CTP) formalism for our calculation and go beyond…

High Energy Physics - Phenomenology · Physics 2025-07-09 Mathias Becker , Emanuele Copello , Julia Harz , Carlos Tamarit

We analyze a simple Split Supersymmetry scenario where fermion masses come from anomaly mediation, yielding m_s ~ 1000 TeV, m_{3/2} ~ 100 TeV, and m_f ~ 1 TeV. We consider non-thermal dark matter production in the presence of moduli, and we…

High Energy Physics - Phenomenology · Physics 2010-02-03 Jared Kaplan

During inflationary preheating, the energy stored in the inflaton field is rapidly converted into excitations of other entropy fields. This stage is characterized by exponential particle production due to parametric resonance and is…

Cosmology and Nongalactic Astrophysics · Physics 2019-05-15 Jie Jiang , Qiuyue Liang , Yi-Fu Cai , Damien A. Easson , Yang Zhang

Sterile neutrinos can be produced in the early universe via interactions with their active counterparts. For small active-sterile mixing angles, thermal equilibrium with the standard model plasma is not reached and sterile neutrinos are…

High Energy Physics - Phenomenology · Physics 2022-07-06 Gonzalo Alonso-Álvarez , James M. Cline

We present a type of dark energy models where the particles of dark energy phi are dynamically produced via a quantum transition at very low energies. The scale where the transition takes places depends on the strength g of the interaction…

Cosmology and Nongalactic Astrophysics · Physics 2009-10-12 A. de la Macorra , F. Briscese

A formulation of cosmology driven by fermions $\psi $ is studied. Assumption that the expectation value of the fermion bilinear is non-zero simplifies the homogeneous solution of the Dirac equations and connects the spinor field with the…

General Relativity and Quantum Cosmology · Physics 2023-06-09 David Benisty

We study massive spin-1/2 fermion production in nonsingular superstring cosmology, taking into account one-loop quantum corrections to a superstring effective action with dilaton and modulus fields. While no creation occurs in the massless…

High Energy Physics - Phenomenology · Physics 2009-11-07 Shinji Tsujikawa , Hiroki Yajima

A thorough account is given of the derivation of uniform semiclassical approximations to the particle and kinetic energy densities of N noninteracting bounded fermions in one dimension. The employed methodology allows the inclusion of…

Quantum Physics · Physics 2015-10-21 Raphael F. Ribeiro , Kieron Burke

We perform a cosmological analysis in which we allow the primordial power spectrum of scalar perturbations to assume a shape that is different with respect to the usual power-law, arising from the simplest models of cosmological inflation.…

Cosmology and Nongalactic Astrophysics · Physics 2016-06-22 Stefano Gariazzo

We investigate the thermodynamic and emergent thermomechanical properties of fermions confined to a one-dimensional quantum ring with effective spin--orbit interactions induced by nonminimal couplings to antisymmetric tensor fields. Using…

Statistical Mechanics · Physics 2026-05-08 João A. A. S. Reis , L. Lisboa-Santos , Edilberto O. Silva

One contribution to any dark sector's abundance comes from its gravitational production during inflation. If the dark sector is weakly coupled to the inflaton and the Standard Model, this can be its only production mechanism. For…

High Energy Physics - Phenomenology · Physics 2021-12-01 Asimina Arvanitaki , Savas Dimopoulos , Marios Galanis , Davide Racco , Olivier Simon , Jedidiah O. Thompson

We perform a cosmological analysis in which we allow the primordial power spectrum of scalar perturbations to assume a shape that is different from the usual power-law predicted by the simplest models of cosmological inflation. We…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-23 S. Gariazzo , C. Giunti , M. Laveder

The connection between a hidden nonthermal sector and a thermal plasma can be established by a light thermal fermion mediator. When the fermion mediator is much lighter than the hidden species, kinematically forbidden decay of the mediator…

High Energy Physics - Phenomenology · Physics 2023-05-10 Shao-Ping Li

Leptogenesis can successfully explain the matter-antimatter asymmetry via out-of-equilibrium decays of heavy Majorana neutrinos in the early Universe. In this article, we focus on non-resonant thermal leptogenesis and the possibility of…

High Energy Physics - Phenomenology · Physics 2018-09-06 K. Moffat , S. Pascoli , S. T. Petcov , H. Schulz , J. Turner
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