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Related papers: Quintessential Inflation from Lorentzian Slow Roll

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In models of coupled dark energy, in which a dark energy scalar field couples to other matter components, it is natural to expect a coupling to the inflaton as well. We explore the consequences of such a coupling in the context of single…

General Relativity and Quantum Cosmology · Physics 2009-10-29 Philippe Brax , Carsten van de Bruck , Lisa M. H. Hall , Joel M. Weller

In this paper, with the presence of swampland conjecture, we use the complex form of a scalar field and investigate the anisotropic constant-roll of an inflationary scenario. Recently, the complex quintessence field has been used to…

General Relativity and Quantum Cosmology · Physics 2022-03-17 Jafar Sadeghi , Saeed Noori Gashti , Mehdi Shokri

We show that models of `just enough' inflation, where the slow-roll evolution lasted only $50-60$ e-foldings, feature modifications of the CMB power spectrum at large angular scales. We perform a systematic and model-independent analysis of…

High Energy Physics - Theory · Physics 2015-06-22 Michele Cicoli , Sean Downes , Bhaskar Dutta , Francisco G. Pedro , Alexander Westphal

Cosmological models in 1+1 dimensions are an ideal setting for investigating the quantum structure of inflationary dynamics -- gravity is renormalizable, while there is room for spatial structure not present in the minisuperspace…

High Energy Physics - Theory · Physics 2015-09-16 Emil J. Martinec , Wynton E. Moore

An alternative to a cosmological constant is quintessence, defined as a slowly-varying scalar field potential V(\phi). If quintessence is observationally significant, an epoch of inflation is beginning at the present epoch, with \phi the…

High Energy Physics - Phenomenology · Physics 2014-11-17 Christopher Kolda , David H. Lyth

The usual description of inflationary fluctuations uses the framework of quantum field theory (QFT) in curved spacetime, in which quantum fluctuations are superimposed on a classical background spacetime. Even for large fluctuations, such…

General Relativity and Quantum Cosmology · Physics 2020-03-11 Sebastian F. Bramberger , Alice Di Tucci , Jean-Luc Lehners

Inflation predicts the generation of cosmological perturbations. Usually, the power spectra for the scalar and tensor modes are calculated with help of the slow roll approximation. In the case of power law inflation an exact result is…

Astrophysics · Physics 2007-05-23 Dominik J. Schwarz , Jerome Martin

By using the relations between the slow-roll parameters and the power spectrum for the single field slow-roll inflation, we derive the scalar spectral tilt $n_s$ and the tensor to scalar ratio $r$ for the constant slow-roll inflation and…

Cosmology and Nongalactic Astrophysics · Physics 2017-09-06 Qing Gao

A generic feature of cosmic quintessence models is the possibility of significant energy density in the scalar field during the radiation dominated epoch. This possibility is even greater if the quintessence field begins in a…

Astrophysics · Physics 2007-05-23 G. J. Mathews , K. Ichiki , T. Kajino , M. Orito , M. Yahiro

We consider the eternal inflation scenario of the slow-roll/chaotic type with the additional element of an objective collapse of the wave function. The incorporation of this new agent to the traditional inflationary setting might represent…

General Relativity and Quantum Cosmology · Physics 2017-10-27 Gabriel Leon

We study slow-roll inflation model controlled by the modular flavor symmetry. In the model, the modulus field plays a role of inflaton and the introduction of the stabilizer field coupled to a modular form in the superpotential produces the…

High Energy Physics - Phenomenology · Physics 2023-07-26 Yoshihiko Abe , Tetsutaro Higaki , Fumiya Kaneko , Tatsuo Kobayashi , Hajime Otsuka

Inflation is often described through the dynamics of a scalar field, slow-rolling in a suitable potential. Ultimately, this inflaton must be identified as the expectation value of a quantum field, evolving in a quantum effective potential.…

High Energy Physics - Phenomenology · Physics 2021-05-11 Jens O. Andersen , Magdalena Eriksson , Anders Tranberg

A very simple non-singular inflationary model is presented where the unique matter content is a radiation fluid. The model slowly contracts from a very large, almost empty and flat spacetime and realizes a bounce. It is then launched to a…

General Relativity and Quantum Cosmology · Physics 2024-03-08 Piero A. P. Molinari , Paola C. M. Delgado , Rodrigo F. Pinheiro , Nelson Pinto-Neto

Different well-know ways to reheat the universe such as instant preheating, the creation of particles nearly or conformally coupled with gravity, or from the decay products of a curvaton field, are revisited and discussed in detail in the…

General Relativity and Quantum Cosmology · Physics 2019-02-20 Jaume Haro

The primordial power spectra of scalar and tensor perturbations during slow-roll inflation are usually calculated with the method of Bessel function approximation. For constant-roll or ultra slow-roll inflation, the method of Bessel…

General Relativity and Quantum Cosmology · Physics 2018-04-09 Zhu Yi , Yungui Gong

Warm Inflation is a scenario in which the inflaton field dissipates its energy during inflation to maintain a subdominant constant radiation bath. Two of its remarkable features are (i) inflation can be realized even by very steep…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-09 Suratna Das , Umang Kumar , Swagat S. Mishra , Varun Sahni

We extend the k-inflation which is a type of kinetically driven inflationary model under the standard inflationary scenario to a possible warm inflationary scenario. The dynamical equations of this warm k-inflation model are obtained. We…

General Relativity and Quantum Cosmology · Physics 2016-12-06 Zhi-Peng Peng , Jia-Ning Yu , Xiao-Min Zhang , Jian-Yang Zhu

At high e-foldings of expansion, the inflation with the quartic potential exhibits the parametric attractor governed by the slowly running Hubble rate. This quasiattractor simplifies the analysis of predictions for the inhomogeneity…

General Relativity and Quantum Cosmology · Physics 2008-06-11 V. V. Kiselev , S. A. Timofeev

We derive analytic bounds on the shape of the primordial power spectrum in the context of single-field inflation. In particular, the steepest possible growth has a spectral index of $n_s - 1 = 4$ once transients have died down. Its primary…

Cosmology and Nongalactic Astrophysics · Physics 2019-06-24 Christian T. Byrnes , Philippa S. Cole , Subodh P. Patil

The slow roll approximation is studied for cosmological models in Hyperextended Scalar-Tensor Theories of Gravity. A procedure to obtain slow roll solutions in non-minimally coupled gravity is outlined and some examples are provided. An…

General Relativity and Quantum Cosmology · Physics 2009-10-28 Diego F. Torres