Spectral Distortion Signatures of Step-like Inflationary Potential

Abstract

In this work, we analyze a power-law inflationary potential enhanced with a step that can introduce features in the primordial power spectrum. We focus on the computation of the Spectral Distortions (SD) induced by these features obtained from the inflationary dynamics. In this scenario, we explore the potential of upcoming experimental missions like PIXIE to detect the SD of the model within a power of $n=2/3$, a power that agrees with recent tensor-to-scalar ratio constraints. The model offers insights into models with cosmological phases and different scalar field dynamics. Introducing a step in the inflaton potential leads to distinct features in the primordial power spectrum, such as oscillations and localized enhancements/suppressions at specific scales. We analyze the impact of three primary parameters$-\beta$, $\delta$, and ${\varphi }_{\text{step}}-$on the amplitude and characteristics of the SD. The ${\varphi }_{\mathrm{step}}$ places the onset of the oscillations in the primordial power spectrum. The $\beta$ parameter significantly influences the magnitude of the $\mu$-SD, with its increase leading to larger SD and vice versa. Similarly, the $\delta$ parameter affects the smoothness of the step in the potential, with larger values resulting in smaller SD. Our findings indicate a distinct parameter space defined by $0.02<\delta /{\mathrm{M}}_{\mathrm{pl}}\lesssim 0.026$, $0.10\lesssim \beta <0.23$, and $7.53\lesssim {\varphi }_{\mathrm{step}}/{\mathrm{M}}_{\mathrm{pl}}\lesssim 7.55$, which produces SD potentially detectable by PIXIE. This region also corresponds to the maximum observed values of $\mu$ and $y$ SD, which in special cases are an order of magnitude larger than the expected for $\Lambda$CDM. However, we also identify parameter ranges where $\mu$ and $y$ SD may not be detectable due to the limitations of current observational technology.

23 pages, 32 figures

References in corpus (27)

• BICEP / Keck XIII: Improved Constraints on Primordial Gravitational Waves using Planck, WMAP, and BICEP/Keck Observations through the 2018 Observing Season
• Monodromy in the CMB: Gravity Waves and String Inflation
• Reheating in Inflationary Cosmology: Theory and Applications
• Generation and Characterization of Large Non-Gaussianities in Single Field Inflation
• Reheating constraints to inflationary models
• The Powers of Monodromy
• Inflation and WMAP three year data: Features have a Future!
• PBHs and secondary GWs from ultra slow roll and punctuated inflation
• CMB polarization features from inflation versus reionization
• Beyond y and μ: the shape of the CMB spectral distortions in the intermediate epoch, 1.5x10^4 < z < 2x10^5
• The synergy between CMB spectral distortions and anisotropies
• Primordial power spectrum from Planck
• Model selection applied to reconstruction of the Primordial Power Spectrum
• Inflation by non-minimal coupling
• CMB spectral distortions revisited: a new take on $\mu$ distortions and primordial non-Gaussianities from FIRAS data
• New constraint on the tensor-to-scalar ratio from the $Planck$ and BICEP/Keck Array data using the profile likelihood
• Reconstruction of Power Spectrum of Primordial Curvature Perturbations on small scales from Primordial Black Hole Binaries scenario of LIGO/VIRGO detection
• TRIS II: search for CMB spectral distortions at 0.60, 0.82 and 2.5 GHz
• ${\varphi }^2$ Inflation at its Endpoint
• Higgs Chaotic Inflation in Standard Model and NMSSM
• Testing dark matter interactions with CMB spectral distortions
• Reconstruction of the primordial power spectra with Planck and BICEP2
• Non-Gaussianity constraints from Planck spectral distortion cross-correlations
• Primordial non-Gaussianity with $\mu$-type and $y$-type spectral distortions: exploiting Cosmic Microwave Background polarization and dealing with secondary sources
• Searching for local features in primordial power spectrum using genetic algorithms
• Least response method to separate CMB spectral distortions from foregrounds
• Spectral Distortions from Axion Monodromy Inflation

Cited by in corpus (2)

• Enhancement of primordial curvature perturbations in $R^3$-corrected Starobinsky-Higgs inflation
• Spectral distortions in the decaying QCD dark matter scenario