Salvaging Power-Law Inflation through Warming

Abstract

Power-Law inflation with scale factor $a\propto t^m$ is investigated in the context of warm inflation. The treatment is performed in the weak and strong dissipation limits. In addition, we discuss the three common cases for the thermal dissipation coefficient $\Gamma (T)$. We compare the theoretical results of the Power-Law model within warm inflation with the observational constraints from Planck $2018$ and BICEP/Keck 2018, as presented by the tensor-to-scalar ratio $r$ and spectral index $n_s$. The model results agree largely with the observations for most of the $\Gamma (T)$ cases. Furthermore, in order to address the problem of exiting the inflationary epoch, we suggest a perturbed modification to the power-law definition so that it becomes affine, and find that this small change indicates a way for having an exit scenario with a suitable e-foldings number. Finally, we examine this perturbation ansatz within the context of cold inflation with exponential potential, and we find that it can accommodate the observational data with sufficient e-foldings. Our study suggests that the power-law inflation and the exponential potential, in both warm and cold inflation contexts, can in principle be made consistent with the observations and with a possible graceful exit.

arXiv commentpdflatex, 15 pages (epjc style), 7 tables, 4 figures, 5 table-figures, major revision, accepted version to appear in EPJC

References in corpus (22)

• Seven-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Interpretation
• Nine-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Parameter Results
• Nine-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Final Maps and Results
• Seven-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Power Spectra and WMAP-Derived Parameters
• Warm Inflation
• How long before the end of inflation were observable perturbations produced?
• Seven-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Are There Cosmic Microwave Background Anomalies?
• Thermally Induced Density Perturbations in the Inflation Era
• Warm Little Inflaton
• Generalized Assisted Inflation
• Dynamics of Assisted Inflation
• On the Realization of Assisted Inflation
• Warm inflation dissipative effects: predictions and constraints from the Planck data
• Searching for Oscillations in the Primordial Power Spectrum: Constraints from Planck (Paper II)
• $\overline{D3}$ Induced Geometric Inflation
• Warm brane inflation with an exponential potential: A consistent realization away from the swampland
• Runaway potentials in warm inflation satisfying the swampland conjectures
• Resurrecting power law inflation in the light of Planck results
• Observational Constraints on Monomial Warm Inflation
• Power-law inflation with a nonminimally coupled scalar field
• On the graceful exit problem in warm inflation
• Realization of Power-Law Inflation & Variants via Variation of the Strong Coupling Constant

Cited by in corpus (5)

• Slow-roll inflation and growth of perturbations in Kaniadakis modification of Friedmann cosmology
• Running and running of the running of the scalar spectral index in warm inflation
• Cosmology from String T-duality and zero-point length
• Resurrecting Vanilla Power Law Inflation with the aid of Continuous Spontaneous Localization in the ACT era
• Warm inflation in Weyl geometric gravity