English
Related papers

Related papers: Loop Corrections in Bispectrum in USR Inflation wi…

200 papers

We calculate the two-loop corrections in primordial power spectrum in models of single field inflation incorporating an intermediate USR phase employed for PBHs formation. Among the total eleven one-particle irreducible Feynman diagrams, we…

High Energy Physics - Phenomenology · Physics 2024-12-16 Hassan Firouzjahi

We revisit the one-loop correction in curvature perturbation power spectrum in models of single field inflation which undergo a phase of ultra slow-roll (USR) inflation. We include the contributions from both the cubic and quartic…

Cosmology and Nongalactic Astrophysics · Physics 2023-10-06 Hassan Firouzjahi

The nature of one-loop corrections to long-wavelength CMB-scale modes in single-field inflation models with an intermediate USR phase remains a subject of active debate. In this work, we perform a detailed investigation into the…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-29 Haidar Sheikhahmadi , Amin Nassiri-Rad

We revisit the one-loop corrections on CMB scale perturbations induced from small scale modes in single field models which undergo a phase of ultra slow-roll inflation. There were concerns that large loop corrections are against the notion…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-08 Hassan Firouzjahi

An estimate of the one-loop correction to the power spectrum of the primordial curvature perturbation is given, assuming it is generated during a phase of single-field, slow-roll inflation. The loop correction splits into two parts, which…

Astrophysics · Physics 2010-02-09 David Seery

Calculating the action and the interaction Hamiltonian at higher orders in cosmological perturbation theory is a cumbersome task. We employ the formalism of EFT of inflation in the decoupling limit for single-field ultra slow-roll (USR)…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-15 Hassan Firouzjahi , Bahar Nikbakht

We investigate the one-loop quantum correction to the power spectrum of primordial curvature perturbations in the ultra-slow-roll (USR) inflationary scenario, incorporating the backreaction effect from curvature perturbations. In the…

General Relativity and Quantum Cosmology · Physics 2025-07-30 Cheng-Jun Fang , Zhen-Hong Lyu , Chao Chen , Zong-Kuan Guo

We calculate the action and the interaction Hamiltonians to all orders in perturbation theory in the model of single field inflation with a transient ultra slow-roll phase. Employing the formalism of EFT of inflation, we obtain a compact…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-15 Hassan Firouzjahi , Bahar Nikbakht

Primordial black holes can be formed from the collapse of large-amplitude perturbation on small scales in the early Universe. Such an enhanced spectrum can be realized by introducing a flat region in the potential of single-field inflation,…

High Energy Physics - Theory · Physics 2024-05-30 Jason Kristiano , Jun'ichi Yokoyama

The one-loop corrections (1LC) to the power spectrum of scalar perturbations arising from cubic interactions in the single-field E-type $\alpha$-attractor models of inflation and primordial black hole (PBH) production are numerically…

General Relativity and Quantum Cosmology · Physics 2025-05-19 Daniel Frolovsky , Sergei V. Ketov

In this paper we compute 1-loop corrections to the bispectrum in the decoupling limit of the Effective Field Theory of Inflation (EFToI). We regulate the divergences by employing dimensional regularization and work in $d=3+\delta$…

High Energy Physics - Theory · Physics 2024-10-11 Supritha Bhowmick , Diptimoy Ghosh , Farman Ullah

As one of the promising candidates of cold dark matter (DM), primordial black holes (PBHs) were formed due to the collapse of over-densed regions generated by the enhanced curvature perturbations during the radiation-dominated era. The…

Cosmology and Nongalactic Astrophysics · Physics 2022-09-21 De-Shuang Meng , Chen Yuan , Qing-guo Huang

We discuss the issue of perturbativity in single-field inflationary models with a phase of ultra slow-roll (USR) tailor suited to generate an order-one abundance of primordial black holes (PBHs). More in detail, we impose the condition that…

Cosmology and Nongalactic Astrophysics · Physics 2024-07-01 Gabriele Franciolini , Antonio Junior Iovino , Marco Taoso , Alfredo Urbano

In canonical single-field inflation, the production of primordial black holes (PBH) requires a transient violation of the slow-roll condition. The transient ultra slow-roll inflation is an example of such scenarios, and more generally, one…

Cosmology and Nongalactic Astrophysics · Physics 2023-08-31 Hayato Motohashi , Yuichiro Tada

We study the one-loop corrections in power spectrum of long gravitational waves induced from small scale modes in the models of single field inflation undergoing a phase of ultra-slow-roll (USR). We show that the spectrum of long tensor…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-05 Hassan Firouzjahi

We present a detailed exposition on the prospects of the formation of Primordial Black Holes (PBHs) during Slow Roll (SR) to Ultra Slow Roll (USR) sharp transitions in the framework of single-field inflation. We use an effective field…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-15 Sayantan Choudhury , Sudhakar Panda , M. Sami

In order to produce appreciable amount of primordial black holes (PBHs), the square amplitude of curvature perturbation must take a large value of $\mathcal{O}(0.01)$, namely, seven digits larger than the value observed by cosmic microwave…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-08 Jason Kristiano , Jun'ichi Yokoyama

Single-field models of inflation might lead to amplified scalar fluctuations on small scales due, for example, to a transient ultra-slow-roll phase. It was argued by Kristiano $\&$ Yokoyama in arXiv:2211.03395 that the enhanced amplitude of…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-15 Matthew W. Davies , Laura Iacconi , David J. Mulryne

[Abridged] In contemporary literature, the calculation of modifications to the inflationary scalar power spectrum due to the loops from the higher order interaction terms in the Hamiltonian have led to a discussion regarding the validity of…

Cosmology and Nongalactic Astrophysics · Physics 2024-11-26 Suvashis Maity , H. V. Ragavendra , Shiv K. Sethi , L. Sriramkumar

Inflationary models predicting a scale-dependent large amplification of the density perturbations have recently attracted a lot of attention because the amplified perturbations can seed a sizable amount of primordial black holes (PBHs) and…

Cosmology and Nongalactic Astrophysics · Physics 2023-06-28 Keisuke Inomata , Matteo Braglia , Xingang Chen , Sébastien Renaux-Petel
‹ Prev 1 2 3 10 Next ›