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This study explores the realization of nonminimally coupled Higgs inflation in the context of no-scale supergravity, investigates the formation of primordial black holes, and examines the potential for observable proton decay within the…

Cosmology and Nongalactic Astrophysics · Physics 2024-04-22 Nadir Ijaz , Maria Mehmood , Mansoor Ur Rehman

We investigate two classes of inflationary models, which lead to a stiff period after inflation that boosts the signal of primordial gravitational waves (GWs). In both families of models studied, we consider an oscillating scalar…

High Energy Physics - Phenomenology · Physics 2024-10-10 Chao Chen , Konstantinos Dimopoulos , Cem Eröncel , Anish Ghoshal

A direct detection of primordial gravitational waves is the ultimate probe for any inflation model. While current CMB bounds predict the generic scale-invariant gravitational wave spectrum from slow-roll inflation to be below the reach of…

Cosmology and Nongalactic Astrophysics · Physics 2016-05-23 Valerie Domcke

One of the fundamental characteristics of slow roll inflation is its generation of tensor perturbations, which manifest as stochastic gravitational waves (GWs). Slow roll inflation results in a nearly scale-invariant GW spectrum that…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-02 Suvashis Maity , Md Riajul Haque

We extend the WKB method for the computation of cosmological perturbations during inflation beyond leading order and provide the power spectra of scalar and tensor perturbations to second order in the slow-roll parameters. Our method does…

General Relativity and Quantum Cosmology · Physics 2009-11-11 R. Casadio , F. Finelli , M. Luzzi , G. Venturi

We study the impact of the use of the power series expression for the primordial tensor spectrum on parameter estimation from future direct detection gravitational wave experiments. The spectrum approximated by the power series expansion…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-19 Sachiko Kuroyanagi , Tomo Takahashi

We propose a novel mechanism for gravitational wave (GW) production sourced by spectator scalar fields during inflation. These fields, while not driving cosmic expansion, generate blue-tilted isocurvature fluctuations that naturally satisfy…

High Energy Physics - Phenomenology · Physics 2025-06-17 Marcos A. G. Garcia , Sarunas Verner

One of the predictions from simple inflation models is stochastic background of Gravitational Waves (\textbf{GW}), or literally what is called Primordial Gravitational Waves (\textbf{PGW}) with a nearly scale--invariant spectrum. To discuss…

General Relativity and Quantum Cosmology · Physics 2025-07-29 Taimur Mohammadi , Behrooz Malekolkalami

Scalar-induced gravitational waves (SIGWs) provide a powerful probe of inflationary dynamics on scales far smaller than those accessible to the cosmic microwave background and large-scale structure. In scenarios with a transient…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-07 Angelo Caravano , Gabriele Franciolini , Sébastien Renaux-Petel

Current measurements of the temperature and polarization anisotropy power spectra of the Cosmic Microwave Background (CMB) seem to indicate that the naive expectation for the slow-roll hierarchy within the most simple inflationary paradigm…

Cosmology and Nongalactic Astrophysics · Physics 2020-12-10 Stefano Gariazzo , Olga Mena , Victor Miralles , Héctor Ramírez , Lotfi Boubekeur

Inflation is a highly favoured theory for the early Universe. It is compatible with current observations of the cosmic microwave background and large scale structure and is a driver in the quest to detect primordial gravitational waves. It…

Cosmology and Nongalactic Astrophysics · Physics 2024-04-19 Tomás Sousa , Deaglan J. Bartlett , Harry Desmond , Pedro G. Ferreira

With Planck cosmic microwave background observations, we established the spectral amplitude and tilt of the primordial power spectrum. Evidence of a red spectral tilt ($n_\mathrm{s}=0.96$) at $8\sigma$ provides strong support for the…

Cosmology and Nongalactic Astrophysics · Physics 2020-08-18 Ivan Debono , Dhiraj Kumar Hazra , Arman Shafieloo , George F. Smoot , Alexei A. Starobinsky

We develop a general formalism for analyzing linear perturbations in multiple-field cosmological inflation based on the gauge-ready approach. Our inflationary model consists of an arbitrary number of scalar fields with non-minimal kinetic…

Astrophysics · Physics 2009-11-13 Joydev Lahiri , Gautam Bhattacharya

Inflation is an early period of accelerated cosmic expansion, thought to be sourced by high energy physics. A key task today is to use the influx of increasingly precise observational data to constrain the plethora of inflationary models…

Cosmology and Nongalactic Astrophysics · Physics 2013-08-05 Joseph Elliston

The detection of Primordial Gravitational Waves (PGWs) is one of the most important goals of modern cosmology since PGWs can both provide substantial evidence for primordial inflation and shed light on its physical nature. Small scale…

Cosmology and Nongalactic Astrophysics · Physics 2021-02-17 William Giarè , Alessandro Melchiorri

We study viable small-field Coleman-Weinberg (CW) inflation models with the help of non-minimal coupling to gravity. The simplest small-field CW inflation model (with a low-scale potential minimum) is incompatible with the cosmological…

High Energy Physics - Phenomenology · Physics 2018-03-28 Kunio Kaneta , Osamu Seto , Ryo Takahashi

Inflationary cosmology represents a well-studied framework to describe the expansion of space in the early universe, as it explains the origin of the large-scale structure of the cosmos and the isotropy of the cosmic microwave background…

Cosmology and Nongalactic Astrophysics · Physics 2019-07-16 I. G. Marian , N. Defenu , U. D. Jentschura , A. Trombettoni , I. Nandori

We investigate the observational viability of a class of $\alpha$-attractors inflationary models in light of the most recent Cosmic Microwave Background (CMB) and Large-Scale Structure (LSS) data. By considering a double-well potential we…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-04 J. G. Rodrigues , S. Santos da Costa , J. S. Alcaniz

Parametric resonance or preheating is a plausible mechanism for bringing about the transition between the inflationary phase and a hot, radiation dominated universe. This epoch results in the rapid production of heavy particles far from…

Astrophysics · Physics 2008-11-26 Richard Easther , John T. Giblin , Eugene A. Lim

We investigate inflationary scenarios driven by a class of potentials which are similar in form to those that arise in certain minimal supersymmetric extensions of the standard model. We find that these potentials allow a brief period of…