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We provide a detailed study of natural inflation with a periodic non-minimal coupling, which is a well-motivated inflationary model that admits an explicit UV completion. We demonstrate that this construction can satisfy the most recent…

Cosmology and Nongalactic Astrophysics · Physics 2024-03-18 Alberto Salvio , Simone Sciusco

The generic prediction for the perturbations generated during slow--roll, single--field inflation, as they appear in the cosmic microwave background (CMB), is a flat, close--to--Gaussian spectrum. We calculate the general solution for a…

Astrophysics · Physics 2007-05-23 S. Gupta

We study the imprints of massive particles with spin on cosmological correlators. Using the framework of the effective field theory of inflation, we classify the couplings of these particles to the Goldstone boson of broken time…

High Energy Physics - Theory · Physics 2016-12-23 Hayden Lee , Daniel Baumann , Guilherme L. Pimentel

We provide a dynamical mechanism to generate localized features during inflation. The local feature is due to a sharp waterfall phase transition which is coupled to the inflaton field. The key effect is the contributions of waterfall…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Ali Akbar Abolhasani , Hassan Firouzjahi , Shahram Khosravi , Misao Sasaki

Space-based missions studying the cosmic microwave background (CMB) have progressively refined the parameter space in conventional models of inflation shortly ($\sim 10^{-37}$ seconds) after the big bang. While most inflationary scenarios…

Cosmology and Nongalactic Astrophysics · Physics 2024-04-18 Jingwei Liu , Fulvio Melia

Inflationary model driven by a scalar field whose potential has a step in the second derivative with respect to the field is considered. For the best fit potential parameter values, the 3-point function and the non-Gaussianity associated…

Cosmology and Nongalactic Astrophysics · Physics 2023-04-11 Rakhi. R , Minu Joy

Inflation driven by a generic self-gravitating medium is an interesting alternative to study the impact of spontaneous spacetime symmetry breaking during a quasi de-Sitter phase, in particular the 4-dimensional diffeomorphism invariance of…

General Relativity and Quantum Cosmology · Physics 2021-02-24 Marco Celoria , Denis Comelli , Luigi Pilo , Rocco Rollo

Primordial non-Gaussianity generated by additional fields during inflation offers a compelling observational target. Heavy fields imprint characteristic oscillatory signals in non-Gaussian correlation functions of the inflaton, a process…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-13 Daniel Green , Jiashu Han , Benjamin Wallisch

The detection of a primordial stochastic gravitational wave background has the potential to reveal unprecedented insights into the early universe, and possibly into the dynamics of inflation. Generically, UV-complete inflationary models…

Cosmology and Nongalactic Astrophysics · Physics 2024-02-08 Vikas Aragam , Sonia Paban , Robert Rosati

We study stochastic inflation in the presence of higher-curvature terms non-minimally coupled to the inflaton. Focusing on quadratic curvature invariants, we single out the Gauss-Bonnet term which is known to avoid ghosts, while having…

General Relativity and Quantum Cosmology · Physics 2026-05-14 Yermek Aldabergenov , Ding Ding , Wei Lin , Yidun Wan

We investigate multi-field inflationary scenarios with fields that drop out of the model in a staggered fashion. This feature is natural in certain multi-field inflationary setups within string theory; for instance, it can manifest itself…

High Energy Physics - Theory · Physics 2009-12-10 Diana Battefeld , Thorsten Battefeld , Anne-Christine Davis

The spin excitations from the nonmagnetic charge-ordered insulating state of $\alpha$-(BEDT-TTF)$_2$I$_3$ at ambient pressure have been investigated by probing the static and low-frequency dynamic spin susceptibilities via site-selective…

Strongly Correlated Electrons · Physics 2016-09-08 Kyohei Ishikawa , Michihiro Hirata , Dong Liu , Kazuya Miyagawa , Masafumi Tamura , Kazushi Kanoda

We investigate the effects of non-zero spatial curvature on cosmic inflation in the light of cosmic microwave background (CMB) anisotropy measurements from the Planck 2018 legacy release and from the 2015 observing season of BICEP2 and the…

Cosmology and Nongalactic Astrophysics · Physics 2022-10-12 Lukas T. Hergt , Fruzsina J. Agocs , Will J. Handley , Michael P. Hobson , Anthony N. Lasenby

A scalar Higgs field can be repeatedly switched on and off when it couples to a classically oscillating scalar modulus field. The modulus flips the Higgs mass term between stable and tachyonic values. We study a cosmological scenario in…

High Energy Physics - Theory · Physics 2020-05-20 JiJi Fan , Matthew Reece , Yi Wang

Primordial non-Gaussianity generated by additional fields present during inflation offers a compelling observational target for galaxy surveys. These fields are of significant theoretical interest since they offer a window into particle…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-27 Daniel Green , Yi Guo , Jiashu Han , Benjamin Wallisch

Fluctuations in the intensity and polarization of the cosmic microwave background (CMB) and the large-scale distribution of matter in the universe each contain clues about the nature of the earliest moments of time. The next generation of…

Particle creation during inflation is considered. It could be important for species whose interaction is of gravitational strength or weaker. A complete but economical formalism is given for spin-zero and spin-half particles, and the…

High Energy Physics - Phenomenology · Physics 2016-08-25 David H. Lyth , David Roberts

Primordial non-Gaussianity signatures of extremely heavy particles are re-examined within a simple alternative to the standard inflationary paradigm, in which the primordial fluctuations and the inflationary spacetime expansion are sourced…

High Energy Physics - Phenomenology · Physics 2020-06-05 Soubhik Kumar , Raman Sundrum

String field theory motivated infinite-derivative models lead to non-local gravity modifications which form a promising class of quantum gravity candidates. In this paper we investigate effects of non-locality on the three-point function…

General Relativity and Quantum Cosmology · Physics 2025-08-07 Alexey S. Koshelev , Abhishek Naskar

We consider true vacuum bubbles generated in a first order phase transition occurring during the slow rolling era of a two field inflation: it is known that gravitational waves are produced by the collision of such bubbles. We find that the…

General Relativity and Quantum Cosmology · Physics 2011-09-09 Carlo Baccigalupi , Luca Amendola , Pierluigi Fortini , Franco Occhionero