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We construct an inflation model with inflaton non-minimally coupled to gravity on a warped DGP brane. Using an exponential potential, we calculate scalar power spectrum, spectral index and the running of the spectral index. We show that for…

High Energy Physics - Theory · Physics 2009-06-11 Kourosh Nozari , Behnaz Fazlpour

Warm inflationary universe models in the context of generalized chaplygin gas, modified chaplygin gas, generalized cosmic chaplygin gas are being studied. The dissipative coefficient of the form $\Gamma\propto T$, weak and strong…

General Relativity and Quantum Cosmology · Physics 2016-10-27 Abdul Jawad , Sadaf Butt , Shamaila Rani

The increasingly stringent observational bounds on primordial gravitational waves strongly constrain inflationary model building, favoring scenarios that predict highly suppressed tensor perturbations. While many viable constructions rely…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-11 Panagiotis G. Stavros , Spyros Basilakos , Emmanuel N. Saridakis

Motivated by recent developments in inflationary cosmology indicating the possibility of obtaining genuinely open universes in some models, we compare the predictions of cold dark matter (CDM) models in open universes with a variety of…

Astrophysics · Physics 2015-06-24 Andrew R Liddle , David H Lyth , David Roberts , Pedro P T Viana

We quantify the degree of fine tuning required to achieve an observationally viable period of inflation in the strongly dissipative regime of warm inflation. The ``fine-tuning'' parameter $\lambda$ is taken to be the ratio of the change in…

General Relativity and Quantum Cosmology · Physics 2023-04-03 Gabriele Montefalcone , Vikas Aragam , Luca Visinelli , Katherine Freese

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

Using the Hubble parameter as new `inverse time' coordinate ($H$-formalism), a new method of reconstructing the inflaton potential is developed also using older results which, in principle, is applicable to any order of the slow-roll…

General Relativity and Quantum Cosmology · Physics 2009-10-28 Eckehard W. Mielke , Franz E. Schunck

The most recent data release from the Atacama Cosmology Telescope (ACT) reveals a larger value of the scalar spectral tilt $n_s$, ruling out a broad class of inflationary attractors. In this paper, we consider inflationary models including…

General Relativity and Quantum Cosmology · Physics 2025-09-03 Qing Gao , Yanjiang Qian , Yungui Gong , Zhu Yi

We investigate Natural Inflation with non-minimal coupling to gravity, characterized either by a quadratic or a periodic term, within the Warm Inflation paradigm during the slow roll stage, in both strong and weak dissipation limits, and…

General Relativity and Quantum Cosmology · Physics 2023-01-25 Mahmoud AlHallak , Khalil Kalid Al Said , Nidal Chamoun , Moustafa Sayem El-Daher

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

We study the amplitude and spectral tilt of density perturbations in the simplest hybrid inflation models. We give an exact expression for the amplitude of quantum fluctuations on all scales in the limit where we can neglect the…

Astrophysics · Physics 2009-06-19 Juan Garcia-Bellido , David Wands

In this work, we study the effects on the relevant observational parameters of an inflationary universe from a chaotic potential with a step. We numerically evolve the perturbation equations within both cold inflation and warm inflation. On…

General Relativity and Quantum Cosmology · Physics 2023-03-09 Clara Rojas , Rafael Hernández-Jiménez

We revisit inflation with non-canonical scalar fields by applying deformed-steepness exponential potentials. We show that the resulting scenario can lead to inflationary observables, and in particular to scalar spectral index and…

General Relativity and Quantum Cosmology · Physics 2021-08-24 Smaragda Lola , Andreas Lymperis , Emmanuel N. Saridakis

We investigate warm inflation in the framework of $f(Q)$ gravity within a Friedmann-Robertson-Walker spacetime. Unlike cold inflation, where the inflaton evolves in isolation, warm inflation features continuous interaction between the…

General Relativity and Quantum Cosmology · Physics 2026-05-29 Tuhina Ghorui , Prabir Rudra , Farook Rahaman , Behnam Pourhassan

We propose an idea to build a bridge between reheating and late-time observations in quintessential inflation by backtracking the evolution of the inflaton field from the present time to the end of reheating. This idea is implemented when…

High Energy Physics - Theory · Physics 2025-03-10 Ok Song An , Jin U Kang , Yong Jin Kim , Ui Ri Mun

Polynomial inflation is a very simple and well motivated scenario. A potential with a concave ``almost'' saddle point at field value $\phi = \phi_0$ fits well the cosmic microwave background (CMB) data and makes testable predictions for the…

High Energy Physics - Phenomenology · Physics 2024-02-28 Manuel Drees , Yong Xu

We investigate inflation in Randall-Sundrum type II brane scenario with closed Friedman-Robertson-Walker (FRW) brane. We consider only power-law potentials of the scalar field and wide range of powers and parameters for them. For our models…

Astrophysics · Physics 2007-05-23 Sergey A. Pavluchenko

We study the planar regime of curvature perturbations for single field inflationary models in an axially symmetric Bianchi I background. In a theory with standard scalar field action, the power spectrum for such modes has a pole as the…

High Energy Physics - Theory · Physics 2014-06-13 Anindya Dey , Ely D. Kovetz , Sonia Paban

We analyze the dynamics of models of warm inflation with general dissipative effects. We consider phenomenological terms both for the inflaton decay rate and for viscous effects within matter. We provide a classification of the asymptotic…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Jose P. Mimoso , Ana Nunes , Diego Pavon

Inflation with a scalar-field potential of the form \lambda (\phi^2-v^2)^2 can be described in terms of a parametrical attractor with critical points, whose driftage depends on the control value of the slowly changing Hubble rate. The…

General Relativity and Quantum Cosmology · Physics 2014-11-20 V. V. Kiselev , S. A. Timofeev