A5084769185- Cosmology and Gravitation Theories
- Dark Matter and Cosmic Phenomena
- Black Holes and Theoretical Physics
- Particle physics theoretical and experimental studies
- Galaxies: Formation, Evolution, Phenomena
- Geophysics and Gravity Measurements
- Solar and Space Plasma Dynamics
- Freezing and Crystallization Processes
- Quantum chaos and dynamical systems
- Stochastic processes and financial applications
- Gamma-ray bursts and supernovae
- Quantum Mechanics and Non-Hermitian Physics
- Atomic and Subatomic Physics Research
- Ionosphere and magnetosphere dynamics
- Advanced Thermodynamics and Statistical Mechanics
- Noncommutative and Quantum Gravity Theories
- Nonlinear Waves and Solitons
- Pulsars and Gravitational Waves Research
- Astro and Planetary Science
- Nuclear physics research studies
- Statistical Mechanics and Entropy
- Scientific Research and Discoveries
- Molecular spectroscopy and chirality
- Astrophysics and Cosmic Phenomena
- Neutrino Physics Research
Universidad Nacional Autónoma de México
2009-2024
Universidad Autónoma de Madrid
2020-2022
Instituto de Física Teórica
2020-2022
The University of Texas at El Paso
2022
Istituto Nazionale di Fisica Nucleare, Sezione di Padova
2022
University of Padua
2022
Consejo Superior de Investigaciones Científicas
2021
Rice University
2016-2020
University of Minnesota
2013-2016
Universidade Federal de Itajubá
2011
Abstract We analyze in detail the perturbative decay of inflaton oscillating about a generic form its potential V (ϕ) = ϕ k , taking into account effects non-instantaneous reheating. show that evolution temperature as function cosmological scale factor depends on spin statistics final state products when > 2. also include inflaton-induced mass states leading to either kinematic suppression or enhancement if are fermionic bosonic respectively. compute maximum reached after inflation,...
We perform a systematic analysis of dark matter production during postinflationary reheating. Following the period exponential expansion, inflaton begins damped oscillations as it decays. These and evolution temperature thermalized decay products depend on shape potential $V(\mathrm{\ensuremath{\Phi}})$. consider potentials form, ${\mathrm{\ensuremath{\Phi}}}^{k}$. Standard matter-dominated occur for $k=2$. In general, may either (or both) maximum after inflation, or reheating temperature,...
In the first stages of inflationary reheating, temperature radiation produced by inflaton decays is typically higher than commonly defined reheating $T_{RH} \sim (Γ_ϕM_P)^{1/2}$ where $Γ_ϕ$ decay rate. We consider effect particle production at temperatures or near maximum attained during reheating. show that impact this early on final abundance depends strongly dependence cross section. For $\langle σv \rangle T^n/M^{n+2}$, and for $n < 6$, any $T_{\rm max}$ diluted later generation...
At the end of inflation, inflaton field decays into an initially nonthermal population relativistic particles which eventually thermalize. We consider production dark matter from this plasma, focusing on prethermal phase. find that for a cross section $\sigma(E)\sim E^n$ with $n> 2$, present abundance is produced during phase its progenitors. For $n\le entropy reheating makes contribution to subdominant compared thermally. As specific examples, we verify irrelevant gravitino in low scale...
We revisit gravitino production following inflation. As a first step, we review the standard calculation of in thermal plasma formed at end post-inflationary reheating when inflaton has completely decayed. Next consider prior to completion reheating, assuming that decay products thermalize instantaneously while they are still dilute. then argue instantaneous thermalization is general good approximation, and also show contribution non-thermal via collisions relatively small. Our final...
We investigate the power spectrum of Non-Cold Dark Matter (NCDM) produced in a state out thermal equilibrium. consider dark matter production from decay scalar condensates (inflaton, moduli), thermalized and non-thermalized particles, non-thermal freeze-in. For each case, we compute NCDM phase space distribution linear spectrum, which features cutoff analogous to that for Warm (WDM). This scale is solely determined by equation NCDM. propose mapping procedure translates WDM Lyman-$\alpha$...
We numerically investigate the gravitational waves generated by head-on collision of equal-mass, self-gravitating, real scalar field solitons (oscillatons) as a function their compactness $\mathcal{C}$. show that there exist three different possible outcomes for such collisions: (1) an excited stable oscillaton low $\mathcal{C}$, (2) merger and formation black-hole intermediate (3) pre-merger collapse both oscillatons into individual black-holes large For (1), excited, aspherical continues...
Recent BICEP/Keck data on the cosmic microwave background, in combination with previous WMAP and Planck data, impose strong new constraints tilt scalar perturbation spectrum, $n_s$, as well tensor-to-scalar ratio, $r$. These constrain number of e-folds inflation, $N_*$, magnitude inflaton coupling to matter, $y$, reheating temperature, $T_{\rm reh}$, which we evaluate attractor models inflation formulated no-scale supergravity. The 68% C.L. region $(n_s, r)$ favours large values $N_*, y$...
Abstract We consider the production of dark matter during process reheating after inflation. The relic density from freeze-in depends on both energy and distribution inflaton scattering or decay products composing radiation bath. compare perturbative non-perturbative calculations in radiation. also (likely) possibility that final state scalar are unstable. Assuming either thermal non-thermal functions, we resulting based these different approaches. show present-day cold can be obtained...
We investigate the out-of-equilibrium production of scalar dark matter (DM) from inflaton condensate during inflation and reheating. assume that this couples only to via a direct quartic coupling is minimally coupled gravity. consider all possible regimes: purely gravitational, weak (perturbative), strong (nonperturbative). For each regime, we use different approaches determine phase space distribution corresponding relic abundance. gravitational quanta are copiously excited resulting in an...
After reviewing the motivations for cosmological inflation formulated in formalism of supersymmetry, we argue that appropriate framework is no-scale supergravity. We then show how to construct within this inflationary models whose predictions tilt spectrum scalar perturbations, $n_s$, and ratio, $r$, tensor perturbations coincide with those $R + R^2$ model proposed by Starobinsky. A more detailed study supergravity reveals a structure closely related $R^2$ modifications minimal...
Abstract In the presence of self-interactions, post-inflationary evolution inflaton field is driven into non-linear regime by resonant growth its fluctuations. The once spatially homogeneous coherent converted a collection particles with non-vanishing momentum. Fragmentation significantly alters energy transfer rate to inflaton's offspring during reheating epoch. this work we introduce formalism quantify effect fragmentation on particle production rates, and determine radiation densities,...
Abstract We consider the effects of fragmentation on post-inflationary epoch reheating. In simple single field models inflation, an inflaton condensate undergoes oscillatory phase once inflationary expansion ends. The equation state depends shape scalar potential, V ( ϕ ), about its minimum. Assuming ) ∼ k , parameter is given by w = P / ρ - 2)/( + 2). evolution and reheating process depend . For ≥ 4, self-interactions may lead to alter process. Indeed, these production a massless gas...
We discuss inflaton decays and reheating in no-scale Starobinsky-like models of inflation, calculating the effective equation-of-state parameter, $w$, during epoch decay, temperature, $T_{\rm reh}$, number inflationary e-folds, $N_*$, comparing analytical approximations with numerical calculations. then illustrate these results applications to based on supergravity motivated by generic string compactifications, including scenarios where is identified as an untwisted-sector matter field...
In gravity mediated models and in particular with strongly stabilized moduli, there is a natural hierarchy between gaugino masses, the gravitino mass moduli masses: $m_{1/2} \ll m_{3/2} m_{\phi}$. Given this hierarchy, we show that 1) problems associated excess entropy production from decay 2) moduli/gravitino decays to neutralinos are non-existent. Placed an inflationary context, amplitude of oscillations severely limited by strong stabilization. Moduli may then never come dominate energy...
Since the building-blocks of supersymmetric models include chiral superfields containing pairs effective scalar fields, a two-field approach is particularly appropriate for inflation based on supergravity. In this paper, we generalize analysis inflationary power spectrum to supergravity with arbitrary Kähler potential. We show how effects in context no-scale can alter model predictions spectral index ns and tensor-to-scalar ratio r, yielding results that interpolate between Planck-friendly...
The hot dense environment of the early universe is known to have produced large numbers baryons, photons, and neutrinos. These extreme conditions may also other long-lived species, including new light particles (such as axions or sterile neutrinos) gravitational waves. effects any such relics can be observed through their unique imprint in cosmic microwave background (CMB), large-scale structure, primordial element abundances, are important determining initial universe. We argue that future...
We consider the decay of inflaton in Starobinsky-like models arising from either an R+R2 theory gravity or N=1 no-scale supergravity models. If Standard Model matter is simply introduced to theory, (which appears when conformally transformed into Einstein frame) couples predominantly Higgs kinetic terms. This will typically lead a reheating temperature ∼3 × 109 GeV. However, if coupled curvature, rate may be suppressed and vanishes for conformal coupling ξ=1/6. Nevertheless, decays through...
The magnitude of primordial tensor perturbations reported by the BICEP2 experiment is consistent with simple models chaotic inflation driven a single scalar field power-law potential ∝ ϕn : n ≃ 2, in contrast to WMAP and Planck results, which favored resembling Starobinsky R+R2 model if running spectral index could be neglected. While quadratic may constructed N = 1 supergravity, these constructions are more challenging no-scale supergravity. We discuss here how can accommodated within...
The magnitude of B-mode polarization in the cosmic microwave background as measured by BICEP2 favours models chaotic inflation with a quadratic $m^2 \phi^2/2$ potential, whereas data from Planck satellite favour small value tensor-to-scalar perturbation ratio $r$ that is highly consistent Starobinsky $R + R^2$ model. Reality may lie somewhere between these two scenarios. In this paper we propose minimal two-field no-scale supergravity model interpolates and Starobinsky-like limiting cases,...
We analyze nucleon decay modes in a no-scale supersymmetric flipped SU(5) GUT model, and contrast them with the predictions for proton decays via dimension-6 operators standard unflipped model. find that these models make very different ratios $\Gamma(p \to \pi^0 \mu^+)/\Gamma(p e^+)$, \pi^+ \bar{\nu})/\Gamma(p K^0 e^+)/\Gamma(p e^+)$ \mu^+)$, also differ variants of model normal- or inverse-ordered light neutrino masses. Upcoming large experiments may have interesting opportunities to...
Conventional scenarios of purely gravitationally produced dark matter with masses below the Hubble parameter at end inflation are in tension cosmic microwave background (CMB) constraints on isocurvature power spectrum. We explore a more general scenario nonminimal coupling between scalar field and gravity, which allows for significantly lighter compared to minimal predictions. By imposing relic abundance, isocurvature, Lyman-$\ensuremath{\alpha}$, big bang nucleosynthesis (BBN) constraints,...
We discuss phenomenological aspects of inflationary models wiith a no-scale supergravity Kähler potential motivated by compactified string models, in which the inflaton may be identified either as modulus or an untwisted matter field, focusing on that make predictions for scalar spectral index ns and tensor-to-scalar ratio r are similar to Starobinsky model. possible patterns soft supersymmetry breaking, exhibiting examples pure type m0 = B0 A0 0, CMSSM with universal ≠ 0 at high scale,...
Supersymmetry is the most natural framework for physics above TeV scale, and corresponding early-Universe cosmology, including inflation, supergravity. No-scale supergravity emerges from generic string compactifications yields a non-negative potential, therefore plausible constructing models of inflation. inflation naturally predictions similar to those Starobinsky model based on $R + R^2$ gravity, with tilted spectrum scalar perturbations: $n_s \sim 0.96$, small values tensor-to-scalar...
We couple a sterile neutrino sector to spin-3/2 particle and show that with Planck reduced coupling, we can obtain sufficiently long lifetime making the good dark matter candidate. this candidate be produced during inflationary reheating through scattering of Standard Model particles. The relic abundance as determined by other experimental measurements is attained for reasonable values temperature $T_{\rm RH} \gtrsim 10^{8}$ GeV. consider two possible gauge invariant couplings extended...