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Related papers: Gauss-Bonnet Inflation after Planck2018

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We consider power-law inflation with a Gauss-Bonnet correction inspired by string theory. We analyze the stability of cosmological perturbations and obtain the allowed parameter space. We find that for GB-dominated inflation ultra-violet…

High Energy Physics - Theory · Physics 2009-09-18 Zong-Kuan Guo , Dominik J. Schwarz

We calculate high-precision constraints on Natural Inflation relative to current observational constraints from Planck 2018 + BICEP/Keck(BK15) Polarization + BAO on $r$ and $n_S$, including post-inflationary history of the universe. We find…

Cosmology and Nongalactic Astrophysics · Physics 2022-01-26 Nina K. Stein , William H. Kinney

We reconsider a recently proposed warm G-inflation scenario in which the Galileon scalar field concurrently dissipates its kinetic energy as the radiation fluid throughout inflation and the universe smoothly enters into a radiation…

General Relativity and Quantum Cosmology · Physics 2018-11-15 Maysam Motaharfar , Erfan Massaeli , Hamid Reza Sepangi

Picking out DBI scalar field as inflation, the slow-rolling inflationary scenario is studied by attributing an exponential time function to scale factor; known as intermediate inflation. The perturbation parameters of the model are…

General Relativity and Quantum Cosmology · Physics 2017-08-15 N. Nazavari , A. Mohammadi , Z. Ossoulian , Kh. Saaidi

Power-Law inflation with scale factor $a \propto t^m$ is investigated in the context of warm inflation. The treatment is performed in the weak and strong dissipation limits. In addition, we discuss the three common cases for the thermal…

Cosmology and Nongalactic Astrophysics · Physics 2023-07-12 M. Alhallak , N. Chamoun , M. S. Eldaher

We study (p)reheating in modular (closed string) inflationary scenarios, with a special emphasis on Kahler moduli/Roulette models. It is usually assumed that reheating in such models occurs through perturbative decays. However, we find that…

High Energy Physics - Theory · Physics 2010-01-15 Neil Barnaby , J. Richard Bond , Zhiqi Huang , Lev Kofman

A new modified string-inspired modular invariant supergravity model is proposed and is applied to realize the slow roll inflation in Einstein frame, so that the model explains WMAP observations very well. Gravitino mass and their production…

High Energy Physics - Phenomenology · Physics 2010-11-23 Yuta Koshimizu , Toyokazu Fukuoka , Kenji Takagi , Hikoya Kasari , Mitsuo J. Hayashi

We study the inflationary phenomenology of a rescaled Einstein-Gauss-Bonnet gravity. In this framework, the gravitational constant of the Einstein-Hilbert term is rescaled due to effective terms active in the high curvature era. Basically,…

General Relativity and Quantum Cosmology · Physics 2025-03-25 V. K. Oikonomou , Ardit Gkioni , Iason Sdranis , Pyotr Tsyba , Olga Razina

In this article we analyze the reconstruction of inflation in the framework of a non-canonical theory. In this sense, we study the viability of reconstructing the background variables assuming a non-lineal kinetic term given by…

Cosmology and Nongalactic Astrophysics · Physics 2024-04-15 Ramon Herrera , Carlos Rios

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

We present predictions of the K\"ahler moduli inflation model for the spectral tilt by parametrising the reheating epoch by an effective equation-of-state parameter and the number of e-foldings of reheating; and taking into account the…

High Energy Physics - Phenomenology · Physics 2017-11-10 Sukannya Bhattacharya , Koushik Dutta , Anshuman Maharana

We study observational viability of Natural Inflation with a tachyon field as inflaton. By obtaining the main perturbation parameters in this model, we perform a numerical analysis on the parameter space of the model and in confrontation…

Cosmology and Nongalactic Astrophysics · Physics 2018-05-23 Narges Rashidi , Kourosh Nozari , Oyvind Gron

In this work, we study the generation of gravitational waves in the E-model inflation with the scalar field non-minimally coupled to the Gauss-Bonnet term. Considering a wall-crossing behavior in the moduli space, we parameterize the…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-09 Tie-Jun Gao , Jian-Xia Guo

A new model for inflation using modified gravity in the Palatini formalism is constructed. Here non-minimal coupling of scalar field h with the curvature R as a general function f(R,h) is considered. Explicit inflation models for some…

General Relativity and Quantum Cosmology · Physics 2021-05-19 Nayan Das , Sukanta Panda

We study the perspectives to extract information about the microphysical parameters that governed the reheating process after cosmic inflation from CMB data. We identify conditions under which the inflaton coupling to other fields can be…

Cosmology and Nongalactic Astrophysics · Physics 2022-09-30 Marco Drewes

In this paper, we undertake a detailed study of real scalar inflation by employing LATTICEEASY simulations to investigate preheating phenomena. Generally, the scalar inflation potential with non-minimal coupling can be approximated by a…

Cosmology and Nongalactic Astrophysics · Physics 2024-03-15 Wei Cheng , Tong Qin , Jiujiang Jiang , Ruiyu Zhou

We study two of the most theoretically promising models of inflation, namely the Natural inflation and the Mutated Hilltop inflation, in the Einstein-Gauss Bonnet(EGB) gravity framework. In this work, we try to explore these models in EGB…

Cosmology and Nongalactic Astrophysics · Physics 2023-01-31 Mayukh R. Gangopadhyay , Hussain Ahmed Khan , Yogesh

The recent Planck results and future releases on the horizon present a key opportunity to address a fundamental question in inflationary cosmology of whether primordial density perturbations have a quantum or thermal origin, i.e. whether…

Cosmology and Nongalactic Astrophysics · Physics 2013-06-20 Sam Bartrum , Arjun Berera , Joao G. Rosa

Recent observations from the Atacama Cosmology Telescope (ACT) indicate a moderate upward shift in the scalar spectral index $n_s$ compared to Planck $2018$, thereby placing tighter constraints on inflationary scenarios. Motivated by these…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-25 Li-Yang Chen , Rongrong Zha , Feng-Yi Zhang

We propose a novel {\it k}-Gauss-Bonnet inflationary model, in which a kinetic term of scalar field is allowed to non-minimally couple to the Gauss-Bonnet topological invariant in the absence of a potential of scalar field. As a result,…

General Relativity and Quantum Cosmology · Physics 2022-02-16 Tuyen M. Pham , Duy H. Nguyen , Tuan Q. Do
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