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Recently, there has been some interest for building supersymmetric models of double inflation. These models, realistic from a particle physics point of view, predict a broken-scale-invariant power spectrum of primordial cosmological…

High Energy Physics - Phenomenology · Physics 2014-11-17 Julien Lesgourgues

We study the generation of local non-Gaussianity in models of canonical single field inflation when their backgrounds are either attractor or non-attractor. We show that the invariance of inflation under space-time diffeomorphisms can be…

High Energy Physics - Theory · Physics 2023-04-13 Rafael Bravo , Gonzalo A. Palma

A recent variant of the inflationary paradigm is that the ``primordial'' curvature perturbations come from quantum fluctuations of a scalar field, subdominant and effectively massless during inflation, called the ``curvaton'', instead of…

Astrophysics · Physics 2009-11-10 David Langlois , Filippo Vernizzi

We consider the examples of single-field inflation models predicting large amplitudes of the curvature perturbation power spectrum at relatively small scales. It is shown that in models with an inflationary potential of double-well type the…

Astrophysics · Physics 2009-02-20 Edgar Bugaev , Peter Klimai

We investigate the enhancement of the power spectra large enough to produce primordial black holes in models with multiple scalar fields. We present analytic solutions for the perturbations in the case of constant turns without the need for…

High Energy Physics - Theory · Physics 2024-09-12 Perseas Christodoulidis , Jinn-Ouk Gong

We derive a theoretical upper bound on the oscillation frequency in the scalar perturbation power spectrum of single-field inflation. Oscillations are most naturally produced by modified vacua with varying phase. When this phase changes…

High Energy Physics - Theory · Physics 2013-12-16 Mark G. Jackson , Gary Shiu

We show that inflationary models with broken rotational invariance generate testable off-diagonal signatures in the correlation between the $\mu$-type distortion and temperature fluctuations of the cosmic microwave background. More…

Cosmology and Nongalactic Astrophysics · Physics 2015-10-07 Maresuke Shiraishi , Michele Liguori , Nicola Bartolo , Sabino Matarrese

Supersolid inflation is a class of inflationary theories that simultaneously breaks time and space reparameterization invariance during inflation, with distinctive features for the dynamics of cosmological fluctuations. We investigate…

Cosmology and Nongalactic Astrophysics · Physics 2017-07-19 Angelo Ricciardone , Gianmassimo Tasinato

Within the class of inflationary models, k-inflation represents the most general single field framework that can be associated with an effective quadratic action for the curvature perturbations and a varying speed of sound. The incoming…

Cosmology and Nongalactic Astrophysics · Physics 2013-09-04 Jerome Martin , Christophe Ringeval , Vincent Vennin

In this paper we provide a consistency relation between the amplitude of the hemispherical bipolar asymmetry, $A$, and the amplitude of the primordial non-Gaussianity in the squeezed limit, $f_{NL}$, as $|A| \lesssim 10^{-1} f_{NL}$. We…

Cosmology and Nongalactic Astrophysics · Physics 2013-10-30 Mohammad Hossein Namjoo , Shant Baghram , Hassan Firouzjahi

We review the relation between the inflationary potential and the spectra of density (scalar) perturbations and gravitational waves (tensor perturbations) produced, with particular emphasis on the possibility of reconstructing the inflaton…

We study how the scalar power spectrum of single-scalar inflation depends functionally on models with features which have been proposed to explain anomalies in the data. We exploit a new formalism based on evolving the norm-squared of the…

General Relativity and Quantum Cosmology · Physics 2016-09-27 D. J. Brooker , N. C. Tsamis , R. P. Woodard

We conduct a thorough study of the comoving curvature perturbation $\mathcal{R}$ in single-field inflation with two stages, represented by a piecewise quadratic potential, where both the first and second derivatives are allowed to be…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-23 Xinpeng Wang , Xiao-Han Ma , Misao Sasaki

The inflationary origin of primordial black holes (PBHs) relies on a large enhancement of the power spectrum $\Delta_\zeta$ of the curvature fluctuation $\zeta$ at wavelengths much shorter than those of the cosmic microwave background…

Cosmology and Nongalactic Astrophysics · Physics 2020-09-17 Gonzalo A. Palma , Spyros Sypsas , Cristobal Zenteno

We consider primordial black hole (PBH) production in inflationary $\alpha$-attractors. We discuss two classes of models, namely models with a minimal polynomial superpotential as well as modulated chaotic ones that admit PBHs. We find that…

Cosmology and Nongalactic Astrophysics · Physics 2019-02-11 Ioannis Dalianis , Alex Kehagias , George Tringas

Large turns in multifield inflation can lead to a very rich phenomenology, but are difficult to realise in supergravity, and typically require large field space curvatures. In this work, we present a mechanism to realise multiple sharp…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-24 Sukannya Bhattacharya , Ivonne Zavala

Inflationary cosmology provides a natural mechanism for the generation of primordial perturbations which seed the formation of observed cosmic structure and lead to specific signals of anisotropy in the cosmic microwave background…

Astrophysics · Physics 2011-07-19 Salman Habib , Andreas Heinen , Katrin Heitmann , Gerard Jungman

We compute the primordial curvature spectrum generated during warm inflation, including shear viscous effects. The primordial spectrum is dominated by the thermal fluctuations of the radiation bath, sourced by the dissipative term of the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 M. Bastero-Gil , A. Berera , R. O. Ramos

We present a gauge-invariant formalism to study the evolution of the curvature and entropy perturbations in the case in which spatial and time variations of the inflaton decay rate into ordinary matter are present. During the reheating…

Astrophysics · Physics 2009-11-10 Sabino Matarrese , Antonio Riotto

We investigate the cosmological perturbation theory and calculate the perturbation spectra in the warm $k$-inflation. Unlike the scalar perturbations of $k$-inflation in the cold inflationary scenario, entropy perturbations should be…

General Relativity and Quantum Cosmology · Physics 2018-04-18 Zhi-Peng Peng , Jia-Ning Yu , Xiao-Min Zhang , Jian-Yang Zhu