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The implications of the recently proposed Trans-Planckian censorship conjecture (TCC) are analyzed in the context of warm inflation. It is found that for a single-stage accelerated expansion the constraints imposed by the censorship are…

High Energy Physics - Phenomenology · Physics 2019-12-25 Arjun Berera , Jaime R. Calderón

In this paper, we evaluate a new refined de Sitter (dS) conjecture perspective. This conjecture provides interesting conditions in studying various inflationary models. Therefore we challenge refined dS conjecture with a general method for…

General Relativity and Quantum Cosmology · Physics 2023-02-14 S. Noori Gashti , J. Sadeghi

If the beginning of inflation is defined at the moment when the vacuum energy of the inflaton starts to dominate, the energy density of the other fields at that moment is (by definition) comparable to the inflaton. Although the fraction…

Cosmology and Nongalactic Astrophysics · Physics 2016-02-10 Kazunori Kohri , Chia-Min Lin , Tomohiro Matsuda

One class of single-field inflationary models compatible with the recently-conjectured Swampland criteria would be those in which a Hubble slow-roll parameter $\epsilon_\text{H}$ is not the same as $\epsilon_\text{V} \sim (V'/V)^2$.…

High Energy Physics - Theory · Physics 2019-03-06 Suddhasattwa Brahma , Md. Wali Hossain

We study the effects of the interaction terms between the inflaton fields on the inflationary dynamics in multi-field models. With power law type potential and interactions, the total number of e-folds may get considerably reduced and can…

High Energy Physics - Theory · Physics 2014-11-18 Jinn-Ouk Gong

In this paper, we analyze the inflationary cosmology using string field theory. This is done by using the zero level contribution from string field theory, which is a non-local tachyonic action. We will use the non-local Friedmann equations…

High Energy Physics - Theory · Physics 2020-12-22 Haidar Sheikhahmadi , Mir Faizal , Ali Aghamohammadi , Saheb Soroushfar , Sebastian Bahamonde

We propose an inflationary scenario, M-flation, in which inflation is driven by three $N\times N$ hermitian matrices $\Phi_i, i=1,2,3$. The inflation potential of our model, which is strongly motivated from string theory, is constructed…

High Energy Physics - Theory · Physics 2010-10-13 Amjad Ashoorioon , Hassan Firouzjahi , M. M. Sheikh-Jabbari

We consider the running of the spectral index as a probe of both inflation itself, and of the overall evolution of the very early universe. Surveying a collection of simple single field inflationary models, we confirm that the magnitude of…

Cosmology and Nongalactic Astrophysics · Physics 2011-03-18 Peter Adshead , Richard Easther , Jonathan Pritchard , Abraham Loeb

Assuming that inflation happened through a series of tunneling in the string theory landscape, it is argued that one can determine the structure of vacua using precise measurements of the scalar spectral index and tensor perturbations at…

High Energy Physics - Theory · Physics 2010-04-02 Amjad Ashoorioon

We provide some comments about the constraints on the inflationary models inferred from the two Swampland criteria which have been recently proposed. In particular we argue that, in the absence of any knowledge about the origin of the…

High Energy Physics - Theory · Physics 2018-11-14 Alex Kehagias , Antonio Riotto

We show how the inclusion of non-perturbative, {\em dynamical} quantum effects on the evolution of the inflaton can allow for an inflationary phase that is both consistent with cosmological constraints {\em and} avoids the problems…

High Energy Physics - Theory · Physics 2019-05-15 R. Holman , B. Richard

Recently we introduced an inflationary setup in which the inflaton fields are matrix valued scalar fields with a generic quartic potential, M-flation. In this work we study the landscape of various inflationary models arising from…

High Energy Physics - Theory · Physics 2010-05-12 Amjad Ashoorioon , Hassan Firouzjahi , Mohammmad Mahdi Sheikh-Jabbari

We study models of inflation where the inflaton corresponds to a flat direction in field space and its mass term is generated by gravity mediated soft supersymmetry breaking at high scale. Assuming the inflaton to have non negligible…

High Energy Physics - Phenomenology · Physics 2007-05-23 Laura Covi

Since trans-Planckian considerations can be associated with the re-definition of the initial vacuum, we investigate further the influence of trans-Planckian physics on the spectra produced by the initial quasi-de Sitter (dS) state during…

General Relativity and Quantum Cosmology · Physics 2018-04-06 M. Mohsenzadeh , E. Yusofi

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 consider thermal, trapped and chromo-natural inflation in light of the swampland criteria and the Trans-Planckian Censorship Conjecture (TCC). Since thermal inflation occurs at energies low compared to those of Grand Unification, it is…

High Energy Physics - Theory · Physics 2023-01-11 Arjun Berera , Robert Brandenberger , Vahid Kamali , Rudnei Ramos

Inflation is the currently accepted paradigm for the beginnings of the Universe. To explain the observed almost scale invariant spectrum of density perturbations with only a slight spectral tilt, inflation must have been "slow roll", that…

High Energy Physics - Theory · Physics 2021-01-07 Hao Geng

The physical properties of our universe at energy scales above the expansion rate during inflation can affect predictions for the ratio between the amplitudes of the primordial scalar and tensor fluctuations. In particular, we study here…

High Energy Physics - Phenomenology · Physics 2008-11-03 Hael Collins

Recently in hep-ph/0605035 and hep-ph/0608138, we have shown that primordial inflation can be embedded within the Minimal Supersymmetric Standard Model, while providing the right amplitude for the density perturbations and a tilted spectrum…

High Energy Physics - Phenomenology · Physics 2007-05-23 Rouzbeh Allahverdi , Anupam Mazumdar

In addition to generating the appropriate perturbation power spectrum, an inflationary scenario must take into account the need for inflation to end subsequently. In the context of single-field inflation models where inflation ends by…

Astrophysics · Physics 2009-11-10 Michaël Malquarti , Samuel M. Leach , Andrew R. Liddle