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We provide a precise and quantitative holographic description of a class of inflationary slow-roll models. The dual QFT is a deformation of a three-dimensional CFT by a nearly marginal operator, which, in the models we consider, generates…

High Energy Physics - Theory · Physics 2013-08-28 Adam Bzowski , Paul McFadden , Kostas Skenderis

Recent studies, in the context of consistency conditions for rapid-turn and third order slow-roll inflation in two-field models, raised the question whether this regime can be sustained for more than a few e-folds of expansion. We answer…

High Energy Physics - Theory · Physics 2024-09-27 Lilia Anguelova

We explore some issues in slow roll inflation in situations where field excursions are small compared to $M_p$. We argue that for small field inflation, minimizing fine tuning requires low energy supersymmetry and a tightly constrained…

High Energy Physics - Phenomenology · Physics 2015-05-30 Michael Dine , Lawrence Pack

In this paper the focus is on inflationary dynamics in the context of Einstein Gauss-Bonnet gravitational theories. We investigate the implications of the slow-roll condition on the slow-roll indices and we investigate how the inflationary…

General Relativity and Quantum Cosmology · Physics 2018-09-26 S. D. Odintsov , V. K. Oikonomou

We present a new approximation scheme that allows us to increase the accuracy of analytical predictions of the power spectra of inflationary perturbations for two specific classes of inflationary models. Among these models are chaotic…

Astrophysics · Physics 2015-06-24 C. A. Terrero-Escalante , D. J. Schwarz , A. A. Garcia

Inflation is now an accepted paradigm in standard cosmology, with its predictions consistent with observations of the cosmic microwave background. It lacks, however, a firm physical theory, with many possible theoretical origins beyond the…

Astrophysics · Physics 2009-01-16 Nishant Agarwal , Rachel Bean

In the framework of $f\left(R, T, R_{ab}T^{ab}\right)$ gravity theory, the slow-roll approximation of the cosmic inflation is investigated, where $T$ is the trace of the energy-momentum tensor $T^{ab}$, $R$ and $R_{ab}$ are the Ricci scalar…

General Relativity and Quantum Cosmology · Physics 2024-11-01 Zhe Feng

Slow-roll inflation is analyzed in the context of modified gravity within the Palatini formalism. As shown in the literature, inflation in this framework requires the presence of non-traceless matter, otherwise it does not occur just as a…

General Relativity and Quantum Cosmology · Physics 2020-11-30 Sabit Bekov , Kairat Myrzakulov , Ratbay Myrzakulov , Diego Sáez-Chillón Gómez

We consider inflation with a constant rate of rolling in which a complex scalar field plays the role of inflaton during the inflationary epoch. We implement the inflationary analysis for an accredited angular speed $\dot{\theta}$ which…

General Relativity and Quantum Cosmology · Physics 2024-05-16 Ramón Herrera , Mehdi Shokri , Jafar Sadeghi

We explore what can be said on the effective temperature and sound speed of a statistical ensemble of fluid phonons present at the onset of a conventional inflationary phase. The phonons are the actual normal modes of the gravitating and…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Massimo Giovannini

We compute the three point correlation functions for primordial scalar and tensor fluctuations in single field inflationary models. We obtain explicit expressions in the slow roll limit where the answer is given terms of the two usual slow…

Astrophysics · Physics 2009-11-07 Juan Maldacena

We study the main properties of the warm inflationary model based on Barrow's solution for the scale factor of the universe. Within this framework we calculate analytically the basic slow roll parameters for different versions of warm…

General Relativity and Quantum Cosmology · Physics 2016-10-12 Vahid Kamali , Spyros Basilakos , Ahmad Mehrabi

A brief review of inflation is presented. After having demonstrated the generality of the inflationary mechanism, the emphasize is put on its simplest realization, namely the single field slow-roll inflationary scenario. Then, it is shown…

Astrophysics · Physics 2007-05-23 Jerome Martin

We show that the prediction for the primordial tensor power spectrum cannot be modified at leading order in derivatives. Indeed, one can always set to unity the speed of propagation of gravitational waves during inflation by a suitable…

Cosmology and Nongalactic Astrophysics · Physics 2014-12-10 Paolo Creminelli , Jérôme Gleyzes , Jorge Noreña , Filippo Vernizzi

Recently, it was proposed that a small true vacuum universe can inflate spontaneously, in principle. Furthermore, there should be matter creation in vacuum inflation due to quantum fluctuations, and the matter created will influence the…

General Relativity and Quantum Cosmology · Physics 2017-05-01 Zhiqiang Huang , Dongfeng Gao , Qing-yu Cai

In this paper we use two methods to constrain the the canonical single-field slow-roll inflation model. The first method exploits the analytic slow-roll-parameter dependence of primordial perturbations, and the second consists of a…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-17 Jun Li , Guang-Hai Guo

We make an extension to recent calculations of the probability density \rho(V) for the volume of the universe after inflation. Previous results have been accurate to leading order in the slow roll parameters \epsilon=\dot{H}/H^2 and…

High Energy Physics - Theory · Physics 2015-06-17 Matthew Lewandowski , Ashley Perko

We study the structure of two-point correlators of the inflationary field fluctuations in order to improve the accuracy and efficiency of the existing methods to calculate primordial spectra. We present a description motivated by the…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-24 José T. Gálvez Ghersi , Andrei V. Frolov

There are well-known criteria on the potential and field-space geometry for determining if slow-roll, slow-turn, multi-field inflation is possible. However, even though it has been a topic of much recent interest, slow-roll, rapid-turn…

High Energy Physics - Theory · Physics 2021-03-17 Vikas Aragam , Sonia Paban , Robert Rosati

We develop a method to compute the slow-roll expansion for the Hubble parameter in inflationary models in a flat Friedmann-Lema\^itre-Robertson-Walker spacetime that is applicable to a wide class of potentials including monomial,…

General Relativity and Quantum Cosmology · Physics 2024-10-07 Gabriel Álvarez , Elena Medina