Inflation from a chaotic potential with a step

Abstract

In this work, we study the effects on the relevant observational parameters of an inflationary universe from a chaotic potential with a step. We numerically evolve the perturbation equations within both cold inflation and warm inflation. On the one hand, in a cold inflation scenario we analyse the scalar power spectrum $P_{\mathcal{R}}$ in terms of the number of e-folds $N_e$, and in terms of the ratio $k/k_0$, where $k_0$ is our pivot scale. We show how $P_{\mathcal{R}}$ oscillates around $0.2<k/k_0<20$. Additionally, we present the evolution of two relevant parameters: the scalar spectral index $n_{\mathrm{s}}$ and the tensor-to-scalar ratio $r$. In fact, more than one region of $(n_{\mathrm{s}},r)$ lies within the observable window (Planck 2018). On the other hand, in the warm inflationary case, we also examine the evolution of $P_{\mathcal{R}}$ in terms of $N_e$ and $k/k_0$. Perturbations are amplified in WI; in fact, $P_{\mathcal{R}}$ can be much larger than the CMB value $P_{\mathcal{R}}>2.22\times 10^{-9}$. This time, the spectral index $n_{\mathrm{s}}$ is clearly blue-tilted, at smaller scales, and the tensor-to-scalar ratio $r$ becomes too low. However, $n_{\mathrm{s}}$ can change from blue-tilted towards red-tilted, since $P_{\mathcal{R}}$ starts oscillating around $k/k_0\sim 40$. Indeed, the result from the step potential skims the Planck contours. Finally, one key aspect of this research was to contrast the features of an inflationary potential between both paradigms, and, in fact, they show similarities and differences. Due to a featured background and a combined effect of entropy fluctuations (only in warm inflation), in both scenarios certain fluctuation scales are not longer ``freeze in'' on super-horizon scales.

arXiv comment21 pages, 16 figures

References in corpus (56)

• SciPy 1.0--Fundamental Algorithms for Scientific Computing in Python
• Array Programming with NumPy
• Planck 2018 results. X. Constraints on inflation
• A new approach to the evolution of cosmological perturbations on large scales
• Warm Inflation
• Adiabatic and entropy perturbations from inflation
• On the Cosmological Implications of the String Swampland
• De Sitter Space and the Swampland
• Thermally Induced Density Perturbations in the Inflation Era
• Inflationary perturbations from a potential with a step
• Large Non-Gaussianities in Single Field Inflation
• Warm Inflation and its Microphysical Basis
• Scalar perturbation spectra from warm inflation
• Warm Inflation in the Adiabatic Regime- a Model, an Existence Proof for Inflationary Dynamics in Quantum Field Theory
• Strong Dissipative Behavior in Quantum Field Theory
• Interpolating the Stage of Exponential Expansion in the Early Universe: a possible alternative with no reheating
• Warm Little Inflaton
• Large-scale curvature and entropy perturbations for multiple interacting fluids
• Warm inflation model building
• Dissipation coefficients from scalar and fermion quantum field interactions
• Is Warm Inflation Possible?
• Inflation and WMAP three year data: Features have a Future!
• General dissipation coefficient in low-temperature warm inflation
• A First Principles Warm Inflation Model that Solves the Cosmological Horizon/Flatness Problems
• Power spectrum for inflation models with quantum and thermal noises
• Warm inflation as a way out of the swampland
• New Constraints on Oscillations in the Primordial Spectrum of Inflationary Perturbations
• Multiple inflation and the WMAP 'glitches'
• Warm Inflation in the light of Swampland Criteria
• Cosmological Perturbations with Multiple Fluids and Fields
• Construction of a robust warm inflation mechanism
• Multiple inflation and the WMAP 'glitches' II. Data analysis and cosmological parameter extraction
• A note on Single-field Inflation and the Swampland Criteria
• Cosmological perturbations in warm inflationary models with viscous pressure
• Dynamical System Analysis for Inflation with Dissipation
• On Perturbations in Warm Inflation
• The Effective Field Theory of Inflation Models with Sharp Features
• The Ubiquitous Inflaton in String-Inspired Models
• On the consistency of warm inflation in the presence of viscosity
• Features in the primordial power spectrum? A frequentist analysis
• Thermal Effects on Pure and Hybrid Inflation
• Dynamical and observational constraints on the Warm Little Inflaton scenario
• Warming up brane-antibrane inflation
• Formation of Primordial Black Holes from Warm Inflation
• Inflationary Perturbations and Precision Cosmology
• Dissipation coefficients for supersymmetric inflatonary models
• Gravity Waves and Primordial Black Holes in Scalar Warm Little Inflation
• Warm inflation within a supersymmetric distributed mass model
• Effects of discontinuities of the derivatives of the inflaton potential
• Dark Radiation and Inflationary Freedom after Planck 2015
• Bayesian analysis of inflationary features in Planck and SDSS data
• Fine-Tuning Solution for Hybrid Inflation in Dissipative Chaotic Dynamics
• CMB anomalies and the effects of local features of the inflaton potential
• Features in single field slow-roll inflation
• Consistency of Tachyacoustic Cosmology with de Sitter Swampland Conjectures
• Are primordial black holes produced by entropy perturbations in single field inflationary models?