Are single-field models of inflation and PBHs production ruled out by ACT observations?

Fuente: arXiv
Guardado en:
Detalles Bibliográficos
Autores principales: Frolovsky, Daniel, Ketov, Sergei V.
Formato: Preprint
Publicado: 2025
Materias:
Acceso en línea:
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
_version_ 1866914198954442752
author Frolovsky, Daniel
Ketov, Sergei V.
author_facet Frolovsky, Daniel
Ketov, Sergei V.
contents The data release from the Atacama Cosmology Telescope (ACT) imposes stronger constraints on primordial black holes (PBHs) formation in single-field inflation models versus the Planck data. In particular, the updated Cosmic Microwave Background (CMB) radiation measurements favour a {\it higher} scalar spectral index $n_s$ and its {\it positive} running $α_s$, which put the single-field models under scrutiny. Even in the absence of PBHs production, the new data constrain many single-field models of inflation. To explore this tension, we study PBHs formation in a concrete viable $α$-attractor E-model. We investigate an impact of bending of the inflaton potential plateau toward reconciling the model with the ACT bounds on the CMB observables. We find that attempts to increase $n_s$ through bending lead to negative values of $α_s$. Those values are disfavored by the ACT bounds just above $2σ$ even for PBHs in the asteroid-mass range, while the tension becomes stronger for heavier PBHs.
format Preprint
id arxiv_https___arxiv_org_abs_2505_17514
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Are single-field models of inflation and PBHs production ruled out by ACT observations?
Frolovsky, Daniel
Ketov, Sergei V.
Cosmology and Nongalactic Astrophysics
General Relativity and Quantum Cosmology
The data release from the Atacama Cosmology Telescope (ACT) imposes stronger constraints on primordial black holes (PBHs) formation in single-field inflation models versus the Planck data. In particular, the updated Cosmic Microwave Background (CMB) radiation measurements favour a {\it higher} scalar spectral index $n_s$ and its {\it positive} running $α_s$, which put the single-field models under scrutiny. Even in the absence of PBHs production, the new data constrain many single-field models of inflation. To explore this tension, we study PBHs formation in a concrete viable $α$-attractor E-model. We investigate an impact of bending of the inflaton potential plateau toward reconciling the model with the ACT bounds on the CMB observables. We find that attempts to increase $n_s$ through bending lead to negative values of $α_s$. Those values are disfavored by the ACT bounds just above $2σ$ even for PBHs in the asteroid-mass range, while the tension becomes stronger for heavier PBHs.
title Are single-field models of inflation and PBHs production ruled out by ACT observations?
topic Cosmology and Nongalactic Astrophysics
General Relativity and Quantum Cosmology
url https://arxiv.org/abs/2505.17514