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We study single-field inflationary models with steep step-like features in the potential that lead to the temporary violation of the slow-roll conditions during the evolution of the inflaton. These features enhance the power spectrum of the…

Cosmology and Nongalactic Astrophysics · Physics 2022-02-18 I. Dalianis , G. P. Kodaxis , I. D. Stamou , N. Tetradis , A. Tsigkas-Kouvelis

In this article, we do a thorough investigation of the competency of the forthcoming Cosmic Microwave Background (CMB) and Galaxy surveys in probing the features in the primordial power spectrum. Primordial features are specific…

Cosmology and Nongalactic Astrophysics · Physics 2022-11-01 Debabrata Chandra , Supratik Pal

We propose a new single field inflation model in which the usual slow-roll inflation is joined to a new period of slow-climb and slow-roll inflation through a short intermediate non-inflationary phase. We then show that primordial curvature…

Cosmology and Nongalactic Astrophysics · Physics 2020-09-02 Chengjie Fu , Puxun Wu , Hongwei Yu

In this work we explore the possibility of variations in the primordial scalar power spectrum around the power-law shape, as predicted by single-field slow-roll inflationary scenarios. We search for the trace of these fluctuations in a…

Cosmology and Nongalactic Astrophysics · Physics 2022-02-09 Marzieh Farhang , Muhammad Sadegh Esmaeilian

We study the evolution of quantum fluctuations of gravity around an inflationary solution in renormalizable quantum gravity, in which the initial scalar-fluctuation dominance is shown by the background-free nature expressed by a special…

High Energy Physics - Theory · Physics 2024-01-19 Ken-ji Hamada

If time-dependent disruptions from slow-roll occur during inflation, the correlation functions of the primordial curvature perturbation should have scale-dependent features, a case which is marginally supported from the cosmic microwave…

Cosmology and Nongalactic Astrophysics · Physics 2018-06-04 Jinn-Ouk Gong , Gonzalo A. Palma , Spyros Sypsas

Primordial magnetic fields are generated during inflation by considering actions that break the conformal invariance of the electromagnetic field. To break the conformal invariance, the electromagnetic fields are coupled either to the…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-22 Sagarika Tripathy , Debika Chowdhury , Rajeev Kumar Jain , L. Sriramkumar

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

The phenomenon of resonant production of particles {\it after} inflation has received much attention in the past few years. In a new application of resonant production of particles, we consider the effect of a resonance {\em during}…

High Energy Physics - Phenomenology · Physics 2009-10-31 Daniel J. H. Chung , Edward W. Kolb , Antonio Riotto , Igor I. Tkachev

Massive particles produced during inflation impact soft limits of primordial correlators. Searching for these signatures presents an exciting opportunity to uncover the particle spectrum in the inflationary epoch. We present…

Cosmology and Nongalactic Astrophysics · Physics 2024-07-12 Samuel Goldstein , Oliver H. E. Philcox , J. Colin Hill , Lam Hui

We study the effects of a general type of features of the inflaton potential on the spectrum and bispectrum of primordial curvature perturbations. These features correspond to a discontinuity in the $n$-th order derivative of the potential…

Cosmology and Nongalactic Astrophysics · Physics 2015-08-25 Alexander Gallego Cadavid

Using the most recent data from the WMAP, ACT and SPT experiments, we update the constraints on models with oscillatory features in the primordial power spectrum of scalar perturbations. This kind of features can appear in models of…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 Micol Benetti , Stefania Pandolfi , Massimiliano Lattanzi , Matteo Martinelli , Alessandro Melchiorri

We examine cosmological perturbations in a dynamical theory of inflation in which an Abelian gauge field couples directly to the inflaton, breaking conformal invariance. When the coupling between the gauge field and the inflaton takes a…

Cosmology and Nongalactic Astrophysics · Physics 2010-10-13 Timothy R. Dulaney , Moira I. Gresham

We analyse the post-inflationary contribution to the stochastic gravitational wave background due to a resonant feature in the scalar power spectrum, which is characterised by an oscillation in $\log(k)$, complementing our previous work…

Cosmology and Nongalactic Astrophysics · Physics 2021-09-08 Jacopo Fumagalli , Sébastien Renaux-Petel , Lukas T. Witkowski

The primordial bispectrum has been considered in the past decade as a powerful probe of the physical processes taking place in the early Universe. Within the inflationary paradigm, the properties of the bispectrum are one of the keys that…

General Relativity and Quantum Cosmology · Physics 2015-03-09 Gabriel Leon , Daniel Sudarsky

[Abridged] A variety of model-dependent as well as model-independent approaches suggest that certain localized features in the primordial scalar power spectrum can lead to a significantly better fit to the observed anisotropies in the…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-16 Alipriyo Hoory , Dhiraj Kumar Hazra , L. Sriramkumar

Inflationary cosmology with a preceding nonsingular bounce can lead to changes on the primordial density fluctuations. One significant prediction is that the amplitude of the power spectrum may undergo a jump at a critical scale. In this…

Cosmology and Nongalactic Astrophysics · Physics 2012-04-10 Jie Liu , Yi-Fu Cai , Hong Li

The Affleck-Dine mechanism is a leading baryogenesis scenario in which scalar condensates form coherently during inflation along supersymmetric flat directions that are lifted by supersymmetry-breaking effects. We update the viable…

High Energy Physics - Phenomenology · Physics 2026-02-10 Yi-Peng Wu , Xingang Chen , Nino Ephremidze , Lingfeng Li

Features in the primordial power spectrum require numerical methods that are both accurate and scalable across the wide class of multifield inflationary models that produce them. Sharp turns in the background trajectories, induced by either…

General Relativity and Quantum Cosmology · Physics 2026-03-31 Guillermo F. Quispe Peña , Johor D. Peñalba Quispitupa , José T. Gálvez Ghersi

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