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Related papers: Warm DBI inflation with constant sound speed

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We discuss under which conditions multi-field cold and warm inflationary models with canonical kinetic energy terms are compatible with the swampland conjectures about the emergence of de Sitter solutions in string theory. We find that…

General Relativity and Quantum Cosmology · Physics 2022-09-14 Orfeu Bertolami , Paulo M. Sá

A warm inflationary Universe in the Randall-Sundrum II model during intermediate inflation is studied. For this purpose, we consider a general form for the dissipative coefficient $\Gamma(T,\phi)=C_{\phi}\,\frac{T^{m}}{\phi^{m-1}}$, and…

General Relativity and Quantum Cosmology · Physics 2015-06-11 Ramón Herrera , Nelson Videla , Marco Olivares

We study Dirac-Born-Infeld (DBI) inflation models with multiple scalar fields. We show that the adiabatic and entropy modes propagate with a common effective sound speed and are thus amplified at the sound horizon crossing. In the small…

High Energy Physics - Theory · Physics 2008-11-26 David Langlois , Sebastien Renaux-Petel , Daniele A. Steer , Takahiro Tanaka

We find successful models of D-brane/anti-brane inflation within a string context. We work within the GKP-KKLT class of type IIB string vacua for which many moduli are stabilized through fluxes, as recently modified to include `realistic'…

High Energy Physics - Theory · Physics 2008-11-26 C. P. Burgess , J. M. Cline , H. Stoica , F. Quevedo

Warm natural inflation is studied for the case of the original cosine potential. The radiation bath during inflation induces a dissipation (friction) rate in the equation of motion for the inflaton field, which can potentially reduce the…

General Relativity and Quantum Cosmology · Physics 2023-03-08 Gabriele Montefalcone , Vikas Aragam , Luca Visinelli , Katherine Freese

We study inflation in the Brans-Dicke gravity as a special model of the scalar-tensor gravity. We obtain the inflationary observables containing the scalar spectral index, the tensor-to-scalar ratio, the running of the scalar spectral index…

Cosmology and Nongalactic Astrophysics · Physics 2016-07-06 B. Tahmasebzadeh , K. Rezazadeh , K. Karami

We study the bispectrum of the primordial curvature perturbation on uniform-density hypersurfaces generated by a kind of the noncanonical warm inflation, wherein the inflation is provided by a noncanonical scalar inflaton field that is…

General Relativity and Quantum Cosmology · Physics 2015-04-09 Xiao-Min Zhang , Jian-Yang Zhu

In this paper we study a new class of inflation models which generalize the Dirac-Born-Infeld (DBI) action with the addition of a nonminimal kinetic coupling (NKC) term. We dubbed this model as the {\it new DBI inflation model}. The NKC…

High Energy Physics - Theory · Physics 2016-08-04 Taotao Qiu

We develop an integral form for the bispectrum in general single-field inflation whose domain of validity includes models of inflation where the background evolution is not constrained to be slowly varying everywhere. Our integral form…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-18 Peter Adshead , Wayne Hu , V Miranda

In models of cosmological inflation motivated by dynamical supersymmetry breaking, the potential driving inflation may be characterized by inverse powers of a scalar field. These models produce observables similar to those typical of the…

High Energy Physics - Phenomenology · Physics 2009-10-31 William H. Kinney , Antonio Riotto

We explore the inflationary evolution and observational viability of the $\alpha$-attractor E-model in the framework of warm inflation, focusing on both weak and strong dissipative regimes, with a dissipation coefficient linear in…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-10 Bhargabi Saha , Malay K. Nandy

Slow-roll of the inflaton field defines the standard dynamics of the inflationary epoch. However, the inflationary system deviates from slow-roll when it encounters an extremely flat region of the inflaton potential, and enters a phase…

Cosmology and Nongalactic Astrophysics · Physics 2024-01-04 Sandip Biswas , Kaushik Bhattacharya , Suratna Das

The recently proposed Swampland Criteria aim to evade any (meta-)stable de Sitter constructions within String landscapes, making it difficult to accommodate accelerating phases, like dark energy domination and inflationary epoch, in…

High Energy Physics - Theory · Physics 2019-04-12 Suratna Das

The amplitude of primordial curvature perturbations is enhanced when a radiation bath at a temperature T>H is sustained during inflation by dissipative particle production, which is particularly significant when a non-trivial statistical…

High Energy Physics - Phenomenology · Physics 2014-04-03 Sam Bartrum , Mar Bastero-Gil , Arjun Berera , Rafael Cerezo , Rudnei O. Ramos , Joao G. Rosa

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

The latest CMB data from ACT DR6, combined with Planck, DESI, and BICEP/Keck, indicate a slight upward shift in the scalar spectral index, placing several previously favored inflationary models under tension. We study an inflationary…

General Relativity and Quantum Cosmology · Physics 2025-11-26 Z. Ossoulian , T. Golanbari , Kh. Saaidi

We consider natural inflation in a warm inflation framework with a temperature-dependent dissipative coefficient $\Gamma \propto T^3$. Natural inflation can be compatible with the Planck 2018 results with such warm assistance. With no a…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-05 Yakefu Reyimuaji , Xinyi Zhang

We consider a non-canonic field in the context of Starobinsky inflation. We work in Einstein-frame. In this frame, the gravitational part of the action is equivalent to the Hilbert-Einstein action, plus a scalar field called scalaron. We…

General Relativity and Quantum Cosmology · Physics 2021-04-28 Salomeh Khoeini-Moghaddam

We perform Markov chain Monte Carlo analyses to put constraints on the non-flat $\phi$CDM inflation model using Planck 2015 cosmic microwave background (CMB) anisotropy data and baryon acoustic oscillation distance measurements. The…

Cosmology and Nongalactic Astrophysics · Physics 2018-10-24 Junpei Ooba , Bharat Ratra , Naoshi Sugiyama

We revisit the constraints that Planck 2015 temperature, polarization and lensing data impose on the parameters of warm inflation. To this end, we study warm inflation driven by a single scalar field with a quartic self interaction…

Cosmology and Nongalactic Astrophysics · Physics 2018-02-26 Richa Arya , Arnab Dasgupta , Gaurav Goswami , Jayanti Prasad , Raghavan Rangarajan