ACT DR6 Insights on the Inflationary Attractor models and Reheating

Fuente: arXiv
Guardado en:
Detalles Bibliográficos
Autores principales: Haque, Md Riajul, Pal, Sourav, Paul, Debarun
Formato: Preprint
Publicado: 2025
Materias:
Acceso en línea:
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
_version_ 1866908347016413184
author Haque, Md Riajul
Pal, Sourav
Paul, Debarun
author_facet Haque, Md Riajul
Pal, Sourav
Paul, Debarun
contents We investigate the observational constraints on $α$-attractor inflationary models and their post-inflationary reheating dynamics in light of the latest CMB data from ACT DR6 combined with Planck18, BICEP/$Keck$ 2018, and DESI (collectively denoted P-ACT-LB-BK18). Focusing on both E and T type attractor potentials, we analyze how inflationary observables namely the scalar spectral index $n_s$ and the tensor-to-scalar ratio $r$ are indirectly influenced by reheating parameters such as the reheating temperature $T_{\text{RH}}$, the inflaton equation-of-state $w_ϕ$, and the inflaton's couplings to Starndard Model particles. We incorporate indirect constraints from the overproduction of primordial gravitational waves (PGWs), particularly via $ΔN_{\rm eff}$ bounds on BBN, which become significant for stiff post-inflationary dynamics. Our results show that E-models permit a wide range of reheating scenarios, including matter-like reheating ($w_ϕ= 0$), while T-models are viable only for $w_ϕ\gtrsim 0.44$. We derive bounds on inflaton-Standard Model couplings for both decay and scattering channels and identify parameter regimes compatible with recent ACT data for successful reheating. These findings establish a robust connection between inflationary theory, thermal history, and particle phenomenology, and provide predictive targets for future CMB missions.
format Preprint
id arxiv_https___arxiv_org_abs_2505_01517
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle ACT DR6 Insights on the Inflationary Attractor models and Reheating
Haque, Md Riajul
Pal, Sourav
Paul, Debarun
Cosmology and Nongalactic Astrophysics
High Energy Physics - Phenomenology
High Energy Physics - Theory
We investigate the observational constraints on $α$-attractor inflationary models and their post-inflationary reheating dynamics in light of the latest CMB data from ACT DR6 combined with Planck18, BICEP/$Keck$ 2018, and DESI (collectively denoted P-ACT-LB-BK18). Focusing on both E and T type attractor potentials, we analyze how inflationary observables namely the scalar spectral index $n_s$ and the tensor-to-scalar ratio $r$ are indirectly influenced by reheating parameters such as the reheating temperature $T_{\text{RH}}$, the inflaton equation-of-state $w_ϕ$, and the inflaton's couplings to Starndard Model particles. We incorporate indirect constraints from the overproduction of primordial gravitational waves (PGWs), particularly via $ΔN_{\rm eff}$ bounds on BBN, which become significant for stiff post-inflationary dynamics. Our results show that E-models permit a wide range of reheating scenarios, including matter-like reheating ($w_ϕ= 0$), while T-models are viable only for $w_ϕ\gtrsim 0.44$. We derive bounds on inflaton-Standard Model couplings for both decay and scattering channels and identify parameter regimes compatible with recent ACT data for successful reheating. These findings establish a robust connection between inflationary theory, thermal history, and particle phenomenology, and provide predictive targets for future CMB missions.
title ACT DR6 Insights on the Inflationary Attractor models and Reheating
topic Cosmology and Nongalactic Astrophysics
High Energy Physics - Phenomenology
High Energy Physics - Theory
url https://arxiv.org/abs/2505.01517