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Related papers: Sigmoidal Inflation

200 papers

In this paper, inflationary cosmology is reviewed, paying particular attention to its observational signatures associated with large-scale density perturbations generated from quantum fluctuations. In the most general scalar-tensor theories…

Cosmology and Nongalactic Astrophysics · Physics 2014-06-13 Shinji Tsujikawa

The precision era of cosmology demands accurate theoretical predictions from inflationary models. In quantitative reheating analyses, inflationary observables depend sensitively on the number of e-folds between horizon exit and the end of…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-22 Debottam Nandi , Simran Yadav , Manjeet Kaur

In most current models of inflation based on a weakly self-coupled scalar matter field minimally coupled to gravity, the period of inflation lasts so long that, at the beginning of the inflationary period, the physical wavelengths of…

High Energy Physics - Theory · Physics 2008-11-26 Jerome Martin , Robert H. Brandenberger

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

Reheating in inflationary cosmology is essential for understanding the early universe, influencing particle production, thermalization, and the primordial power spectrum. Crucial quantities defined during the reheating epoc, such as the…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-16 Gabriel German

Cosmological inflation is studied in the case where the inflaton is the overall modulus $T$ for an orbifold. General forms of the (non-perturbative) superpotential are considered to ensure that $G=K+{\rm ln}|W|^2$ is modular invariant. We…

High Energy Physics - Theory · Physics 2009-10-31 D. Bailin , G. V. Kraniotis , A. Love

In this work, we study the early universe inflation and the post-inflation reheating era employing an inverse tangent potential of the form $V=V_0 \cdot[tan^{-1}(\frac{\kappa \phi}{m_p})]^2$, where $\kappa$ is a free parameter of the…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-24 Mayur Abhisheki , Prasanta Kumar Das

Prediction of inflationary observables from the temperature fluctuation of Cosmic Microwave Background (CMB) can play a pivotal role in predicting the reheating dynamics in the early universe. In this work, we highlight how the inflationary…

High Energy Physics - Phenomenology · Physics 2025-05-21 Anirban Biswas , Sougata Ganguly , Dibyendu Nanda , Sujit Kumar Sahoo

A self-consistent pre-inflationary extension of the inflationary scenario with the Starobinsky potential, favored by Planck data, is studied using techniques from loop quantum cosmology (LQC). The results are compared with the quadratic…

General Relativity and Quantum Cosmology · Physics 2016-05-25 Béatrice Bonga , Brajesh Gupt

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 present a simple formula that allows to calculate the value of the inflaton field, denoted by $\phi$, at the scale with wavenumber mode $k$. In the extreme case of instantaneous reheating $\phi_k$ is calculated exactly and all…

Cosmology and Nongalactic Astrophysics · Physics 2020-05-26 Gabriel German

In this paper we will analyze generic predictions of an inflection-point model of inflation with Hubble-induced corrections and study them in light of the Planck data. Typically inflection-point models of inflation can be embedded within…

High Energy Physics - Phenomenology · Physics 2013-07-29 Sayantan Choudhury , Anupam Mazumdar , Supratik Pal

A new modified string-inspired modular invariant supergravity model is proposed and is applied to realize the slow roll inflation in Einstein frame. Because inflation deals with Planck scale physics, the dilaton can be a strong candidate…

High Energy Physics - Phenomenology · Physics 2011-04-22 Mitsuo J. Hayashi , Yuta Koshimizu , Toyokazu Fukuoka , Kenji Takagi , Hikoya Kasari

We consider an inflationary model motivated by quantum effects of gravitational and matter fields near the Planck scale. Our Lagrangian is a re-summed version of the effective Lagrangian recently obtained by Demmel, Saueressig and…

General Relativity and Quantum Cosmology · Physics 2018-08-15 Lei-Hua Liu , Tomislav Prokopec , Alexei A. Starobinsky

The advancement in the observational cosmology of the early universe such as Cosmic Microwave Background (CMB) observations, puts severe constraints on the inflationary models. Many inflationary models have been ruled out by CMB,…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-20 Yogesh , Mehnaz Zahoor , Kashif Ali Wani , Imtiyaz Ahmad Bhat

We place observational constraints on slow-variation single-field inflationary models by carrying out the cosmological Monte Carlo simulation with the recent data of Planck combined with the WMAP large-angle polarization, baryon acoustic…

Cosmology and Nongalactic Astrophysics · Physics 2013-11-12 Shinji Tsujikawa , Junko Ohashi , Sachiko Kuroyanagi , Antonio De Felice

Slow roll reconstruction is derived from the Hamilton-Jacobi formulation of inflationary dynamics. It automatically includes information from sub-leading terms in slow roll, and facilitatesthe inclusion of priors based on the duration on…

Astrophysics · Physics 2009-06-23 Peter Adshead , Richard Easther

In this paper we will discuss a model which describes the cause of inflation by a topological transition. The guiding principle is the choice of an exotic smoothness structure for the space-time. Here we consider a space-time with topology…

General Relativity and Quantum Cosmology · Physics 2014-01-21 T. Asselmeyer-Maluga , J. Krol

Reheating is the the epoch which connects inflation to the subsequent hot Big-Bang phase. Conceptually very important, this era is however observationally poorly known. We show that the current Planck satellite measurements of the Cosmic…

Cosmology and Nongalactic Astrophysics · Physics 2015-10-08 Jerome Martin , Christophe Ringeval , Vincent Vennin

In this paper, an elegant mathematical approach is introduced to solve the equations of warm inflationary model without using extra approximations other than slow-roll. This important inflationary method known as Hamilton-Jacobian…

General Relativity and Quantum Cosmology · Physics 2020-04-08 R. Saleem , M. Zubair