scholarly journals Reheating in small-field inflation on the brane: the swampland criteria and observational constraints in light of the PLANCK 2018 results

2021 ◽  
Vol 81 (6) ◽  
Author(s):  
Constanza Osses ◽  
Nelson Videla ◽  
Grigoris Panotopoulos
Keyword(s):  
Inflationary Universe ◽  
Observational Constraints ◽  
Small Field ◽  
De Sitter ◽  
Brane Cosmology ◽  
Planck Mass ◽  
Brane Model ◽  
Cosmological Inflation ◽  
Refined Version

AbstractWe study cosmological inflation and its dynamics in the framework of the Randall–Sundrum II brane model. In particular, we analyze in detail four representative small-field inflationary potentials, namely Natural inflation, Hilltop inflation, Higgs-like inflation, and Exponential SUSY inflation, each characterized by two mass scales. We constrain the parameters for which a viable inflationary Universe emerges using the latest PLANCK results. Furthermore, we investigate whether or not those models in brane cosmology are consistent with the recently proposed Swampland Criteria, and give predictions for the duration of reheating as well as for the reheating temperature after inflation. Our results show that (i) the distance conjecture is satisfied, (ii) the de Sitter conjecture and its refined version may be avoided, and (iii) the allowed range for the five-dimensional Planck mass, $$M_5$$ M 5 , is found to be $$10^5\,\text {TeV}\lesssim M_5\lesssim 10^{12}\,\text {TeV}$$ 10 5 TeV ≲ M 5 ≲ 10 12 TeV . Our main findings indicate that non-thermal leptogenesis cannot work within the framework of RS-II brane cosmology, at least for the inflationary potentials considered here.

PRIMORDIAL BLACK HOLE PAIR CREATION IN R2 THEORY

1998 ◽  
Vol 13 (28) ◽  
pp. 2289-2293 ◽  
Author(s):  
B. C. PAUL ◽  
S. MUKHERJEE ◽  
G. P. SINGH ◽  
A. BEESHAM
Keyword(s):  
Black Holes ◽  
Semiclassical Approximation ◽  
Pair Creation ◽  
Quadratic Term ◽  
Inflationary Universe ◽  
Primordial Black Hole ◽  
Primordial Black Holes ◽  
De Sitter ◽  
Gravitational Action ◽  
Spatial Section

The probability for quantum creation of an inflationary universe with a pair of black holes has been studied in semiclassical approximation with Hartle–Hawking boundary conditions, assuming a gravitational action which includes a quadratic term in the scalar curvature αR2, α being a constant. The action of the instanton responsible for creating such a universe, with a spatial section with S1×S2 topology, is seen to be less than that of a de Sitter S3 instanton, unless α<-1/(8Λ), where Λ is the cosmological constant. Since negative α implies a classical instability, the probability for production of primordial black holes seems to be suppressd in R2-theory.

scholarly journals Building models of inflation in no-scale supergravity

2020 ◽  
pp. 2030011
Author(s):  
John Ellis ◽  
Marcos A. G. García ◽  
Natsumi Nagata ◽  
Dimitri V. Nanopoulos ◽  
Keith A. Olive ◽  
...  
Keyword(s):  
Cold Dark Matter ◽  
Planck Scale ◽  
Neutrino Masses ◽  
De Sitter ◽  
Building Models ◽  
Scale Models ◽  
Cosmological Inflation ◽  
Text Model ◽  
Hilbert Action ◽  
Scalar Perturbations

After reviewing the motivations for cosmological inflation formulated in the formalism of supersymmetry, we argue that the appropriate framework is that of no-scale supergravity. We then show how to construct within this framework inflationary models whose predictions for the tilt in the spectrum of scalar perturbations, [Formula: see text], and the ratio, [Formula: see text], of tensor and scalar perturbations coincide with those of the [Formula: see text] model of inflation proposed by Starobinsky. A more detailed study of no-scale supergravity reveals a structure that is closely related to that of [Formula: see text] modifications of the minimal Einstein–Hilbert action for general relativity, opening avenues for constructing no-scale de Sitter and anti-de Sitter models by combining pairs of Minkowski models, as well as generalizations of the original no-scale Starobinsky models of inflation. We then discuss the phenomenology of no-scale models of inflation, including inflaton decay and reheating, and then the construction of explicit scenarios based on SU(5), SO(10) and string-motivated flipped SU(5)×U(1) GUT models. The latter provides a possible model of almost everything below the Planck scale, including neutrino masses and oscillations, the cosmological baryon asymmetry and cold dark matter, as well as [Formula: see text] and [Formula: see text].

scholarly journals INFLATIONARY DILATONIC de SITTER UNIVERSE FROM ${\mathcal N} = 4$ SUPER-YANG–MILLS THEORY PERTURBED BY SCALARS

2003 ◽  
Vol 18 (18) ◽  
pp. 1257-1264
Author(s):  
JOHN QUIROGA HURTADO
Keyword(s):  
Effective Action ◽  
Initial Conditions ◽  
Equations Of Motion ◽  
Scale Factor ◽  
Conformal Anomaly ◽  
Inflationary Universe ◽  
De Sitter ◽  
Yang Mills ◽  
The Stability ◽  
Super Yang Mills Theory

In this paper a quantum [Formula: see text] super-Yang–Mills theory perturbed by dilaton-coupled scalars, is considered. The induced effective action for such a theory is calculated on a dilaton-gravitational background using the conformal anomaly found via AdS/CFT correspondence. Considering such an effective action (using the large N method) as a quantum correction to the classical gravity action with cosmological constant we study the effect from dilaton to the scale factor (which corresponds to the inflationary universe without dilaton). It is shown that, depending on the initial conditions for the dilaton, the dilaton may slow down, or accelerate, the inflation process. At late times, the dilaton is decaying exponentially. At the end of this work, we consider the question how the perturbation of the solution for the scale factor affects the stability of the solution for the equations of motion and therefore the stability of the Inflationary Universe, which could be eternal.

scholarly journals Logarithmic Corrections to the FRW Brane Cosmology from 5d Schwarzschild–de Sitter Black Hole

2003 ◽  
Vol 18 (19) ◽  
pp. 3395-3416 ◽  
Author(s):  
Shin'ichi Nojiri ◽  
Sergei D. Odintsov ◽  
Sachiko Ogushi
Keyword(s):  
Black Hole ◽  
Black Hole Entropy ◽  
Slight Modification ◽  
Thermal Fluctuations ◽  
De Sitter ◽  
Brane Cosmology ◽  
Verlinde Formula ◽  
Logarithmic Corrections ◽  
Constant Change ◽  
Sds Black Hole

Thermodynamics of 5d SdS black hole is considered. Thermal fluctuations define the (sub-dominant) logarithmic corrections to black hole entropy and then to Cardy–Verlinde formula and to FRW brane cosmology. We demonstrate that logarithmic terms (which play the role of effective cosmological constant) change the behavior of 4d spherical brane in dS, SdS or Nariai bulk. In particularly, bounce Universe occurs or 4d dS brane expands to its maximum and then shrinks. The entropy bounds are also modified by next-to-leading terms. Out of braneworld context the logarithmic terms may suggest slight modification of standard FRW cosmology.

scholarly journals Interacting dark energy model in the brane scenario: A dynamical system analysis

2019 ◽  
Vol 16 (08) ◽  
pp. 1950115
Author(s):  
Sujay Kr. Biswas ◽  
Subenoy Chakraborty
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Scalar Field ◽  
Critical Points ◽  
System Analysis ◽  
Evolution Equations ◽  
Field Potential ◽  
Brane Cosmology ◽  
Brane Model ◽  
Barotropic Equation

The present work is a second in the series of investigations of the background dynamics in brane cosmology when dark energy is coupled to dark matter by a suitable interaction. Here, dark matter is chosen in the form of perfect fluid with barotropic equation of state, while a real scalar field with self-interacting potential is chosen as dark energy. The scalar field potential is chosen as exponential or hyperbolic in nature and three different choices for the interactions between the dark species are considered. In the background of spatially flat, homogeneous and isotropic Friedmann–Robertson–Walker (FRW) brane model, the evolution equations are reduced to an autonomous system by suitable transformation of variables and a series of critical points are obtained for different interactions. By analyzing the critical points, we have found a cosmologically viable model describing an early inflationary scenario to dark energy-dominated era connecting through a matter-dominated phase.

scholarly journals Rip brane cosmology from a viscous holographic dark fluid

2020 ◽  
Vol 17 (06) ◽  
pp. 2050087 ◽  
Author(s):  
I. Brevik ◽  
A. V. Timoshkin
Keyword(s):  
Dark Energy ◽  
Energy Conservation ◽  
Bulk Viscosity ◽  
Holographic Dark Energy ◽  
Holographic Principle ◽  
De Sitter ◽  
Brane Cosmology ◽  
Viscous Cosmology ◽  
Dark Fluid ◽  
Analytical Expressions

This paper is devoted to the application of the holographic principle to describe Rip brane cosmological models in the presence of a bulk viscosity. We make use of the generalized infrared-cutoff holographic dark energy, introduced by Nojiri and Odintsov. We consider various examples: Rip brane cosmology corresponding to the Little Rip case, asymptotic de Sitter theory, and the so-called Big Freeze theory leading to a singularity. Analytical expressions for infrared cutoffs, as well as the particle and the future horizons at the brane, are obtained. The equations for energy conservation on the brane within the holographic theory are obtained in each case. The correspondence between viscous cosmology and holographic cosmology on the brane is shown.

CLASSICAL PERTURBATIONS FROM DECOHERENCE OF QUANTUM FLUCTUATIONS IN THE INFLATIONARY UNIVERSE

1990 ◽  
Vol 05 (28) ◽  
pp. 2311-2317 ◽  
Author(s):  
ROBERT BRANDENBERGER ◽  
RAYMOND LAFLAMME ◽  
MILAN MIJIĆ
Keyword(s):  
Scalar Field ◽  
Coherence Length ◽  
Quantum Fluctuations ◽  
Inflationary Universe ◽  
De Sitter ◽  
Density Perturbations ◽  
Hubble Radius ◽  
Universe Models

The evolution of a scalar field interacting with an environment in the de Sitter phase of an inflationary Universe is studied. The environment is taken to be a second scalar field. It is shown that the coherence length of the quantum fluctuations rapidly decreases after the wavelength of the perturbation crosses the Hubble radius. Hence, the fluctuations can be interpreted as classical. This lends support to the usual derivation of the spectrum of density perturbations in inflationary Universe models.

Observational constraints on accelerating brane cosmology with exchange between the bulk and brane

2006 ◽  
Vol 73 (6) ◽  
Author(s):  
K. Umezu ◽  
K. Ichiki ◽  
T. Kajino ◽  
G. J. Mathews ◽  
R. Nakamura ◽  
...  
Keyword(s):  
Observational Constraints ◽  
Brane Cosmology

scholarly journals FROM DE SITTER TO DE SITTER: A NON-SINGULAR INFLATIONARY UNIVERSE DRIVEN BY VACUUM

2006 ◽  
Vol 15 (12) ◽  
pp. 2241-2247 ◽  
Author(s):  
SAULO CARNEIRO
Keyword(s):  
Vacuum Energy ◽  
Cosmological Solution ◽  
Inflationary Universe ◽  
Late Time ◽  
De Sitter ◽  
Classical Analysis ◽  
Huge Amount ◽  
Matter Production ◽  
The Standard Model ◽  
De Sitter Universe

A semi-classical analysis of vacuum energy in the expanding space–time suggests that the cosmological term decays with time, with a concomitant matter production. For early times we find, in Planck units, Λ ≈ H4, where H is the Hubble parameter. The corresponding cosmological solution has no initial singularity, existing since an infinite past. During an infinitely long period we have a quasi-de Sitter, inflationary universe, with H ≈ 1. However, at a given time, the expansion undertakes a phase transition, with H and Λ decreasing to nearly zero in a few Planck times, producing a huge amount of radiation. On the other hand, the late-time scenario is similar to the standard model, with the radiation phase followed by a dust era, which tends asymptotically to a de Sitter universe, with vacuum dominating again.

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