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Reheating connects the inflationary universe to the radiation-dominated evolution of standard Big Bang cosmology. Due to the lack of direct observations, we rely on indirect bounds on this phase from the Cosmic Microwave Background (CMB)…

Cosmology and Nongalactic Astrophysics · Physics 2021-08-17 Pankaj Saha

Constant roll inflation is analyzed in the presence of multi scalar fields which are assumed to be described by a constant roll rate each. The different cases are studied and the corresponding potentials are reconstructed. The exact…

General Relativity and Quantum Cosmology · Physics 2021-01-04 Merce Guerrero , Diego Rubiera-Garcia , Diego Saez-Chillon Gomez

Particle decay during inflation is studied by implementing a dynamical renormalization group resummation combined with a small Delta expansion. Delta measures the deviation from the scale invariant power spectrum and regulates the infrared.…

Astrophysics · Physics 2008-11-26 D. Boyanovsky , H. J. de Vega , N. G. Sanchez

Cosmological $\alpha$-attractors stand out as particularly compelling models to describe inflation in the very early universe, naturally meeting tight observational bounds from cosmic microwave background (CMB) experiments. We investigate…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-22 Laura Iacconi , Hooshyar Assadullahi , Matteo Fasiello , David Wands

It is known that if the standard slow-roll inflation is followed by a power-law inflationary regime, then the trans-Planckian modes may be safely be contained in the Hubble horizon and never exit it during inflation. In this work we…

General Relativity and Quantum Cosmology · Physics 2026-01-29 S. D. Odintsov , V. K. Oikonomou

We study the detectability, given CMB polarization maps, of departures from the inflationary consistency equation, r \equiv T/S \simeq -5 n_T, where T and S are the tensor and scalar contributions to the quadrupole variance, respectively.…

Astrophysics · Physics 2009-11-07 Yong-Seon Song , Lloyd Knox

We numerically compute features in the power-spectrum that originate from the decay of fields during inflation. Using a simple, phenomenological, multi-field setup, we increase the number of fields from a few to thousands. Whenever a field…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-17 Diana Battefeld , Thorsten Battefeld , John T. Giblin , Evan K. Pease

If the beginning of inflation is defined at the moment when the vacuum energy of the inflaton starts to dominate, the energy density of the other fields at that moment is (by definition) comparable to the inflaton. Although the fraction…

Cosmology and Nongalactic Astrophysics · Physics 2016-02-10 Kazunori Kohri , Chia-Min Lin , Tomohiro Matsuda

We consider a model in which a pseudo-scalar field $\sigma$ rolls for some e-folds during inflation, sourcing one helicity of a gauge field. These fields are only gravitationally coupled to the inflaton, and therefore produce scalar and…

Cosmology and Nongalactic Astrophysics · Physics 2016-01-27 Ryo Namba , Marco Peloso , Maresuke Shiraishi , Lorenzo Sorbo , Caner Unal

We study inflation in a random multifield potential, using techniques developed by Marsh et al. The potential is a function of a large number of fields, and we choose parameters so that inflation only occurs in regions where the potential…

High Energy Physics - Theory · Physics 2016-08-02 Ben Freivogel , Roberto Gobbetti , Enrico Pajer , I-Sheng Yang

We study the cosmological inflation from the viewpoint of the moduli stabilization. We study the scenario that the superpotential has a large value during the inflation era enough to stabilize moduli, but it is small in the true vacuum.…

High Energy Physics - Theory · Physics 2015-05-20 Tatsuo Kobayashi , Manabu Sakai

A bidimensional parameter space of unitary area is introduced to study phenomenologically the dynamic and thermodynamic behavior of inflationary models driven by a scalar field coupled to a thermal component. In this enlarged context the…

Astrophysics · Physics 2010-01-06 J. M. F. Maia , J. A. S. Lima

We study a model of inflation based on $\mathcal{N}=1$ supergravity essentially depending on one effective parameter. Under a field transformation we show that this model turns out to be equivalent to a previously studied supergravity model…

Cosmology and Nongalactic Astrophysics · Physics 2020-01-13 Gabriel Germán , Juan Carlos Hidalgo , Francisco X. Linares Cedeño , Ariadna Montiel , J. Alberto Vázquez

We discuss new mechanisms to stop the relaxion field during inflation. They can be realized in a generic model, including the original model but in a quite different parameter region. We consider a fast-rolling relaxion field, which can go…

High Energy Physics - Phenomenology · Physics 2020-01-29 Masahiro Ibe , Yutaro Shoji , Motoo Suzuki

We discuss bispectra of single-field inflationary models described by general Lorentz invariant Lagrangians that are at most first order in field derivatives, including the fast-roll models investigated by Noller and Magueijo. Based on a…

Cosmology and Nongalactic Astrophysics · Physics 2011-12-22 Thorsten Battefeld , Jan Grieb

We revisit the renormalizable polynomial inflection point model of inflation, focusing on the small field scenario which can be treated fully analytically. In particular, the running of the spectral index is predicted to be $\alpha = -1.43…

High Energy Physics - Phenomenology · Physics 2021-09-22 Manuel Drees , Yong Xu

Using $\delta N$ formalism, in the context of a generic multi-field inflation driven on a non-flat field space background, we revisit the analytic expressions of the various cosmological observables such as scalar/tensor power spectra,…

High Energy Physics - Theory · Physics 2014-10-07 Xin Gao , Tianjun Li , Pramod Shukla

We solve analytically the ellipsoidally expanding fireball hydrodynamics with source terms in the momentum and the energy equations, using the non-relativistic approximation. We find that energy transport from high pt jets of gluons to the…

Nuclear Theory · Physics 2009-11-07 T. Csorgo , J. Zimanyi

We extend previous classifications of inflationary models by means of their behaviour at large-N, where N is the number of e-foldings. In addition to the perturbative 1/N case, whose slow-roll parameters fall off as powers of 1/N, we…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 Juan Garcia-Bellido , Diederik Roest

Potential slow-roll parameters are widely used in inflationary cosmology to estimate the scalar and tensor perturbation amplitudes and the scalar spectral index, although the inflationary observables are fundamentally expressed in terms of…

General Relativity and Quantum Cosmology · Physics 2026-05-19 Jose Mathew
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