English
Related papers

Related papers: The Strong Multifield Slowroll Condition and Spira…

200 papers

We show that a corpuscular description of gravity can lead to an inflationary scenario similar to Starobinsky's model without requiring the introduction of the inflaton field. All relevant properties are determined by the number of…

General Relativity and Quantum Cosmology · Physics 2018-10-30 Roberto Casadio , Andrea Giugno , Andrea Giusti

We constrain slow-roll inflationary models using the recent WMAP data combined with data from the VSA, CBI, ACBAR and 2dF experiments. We find the slow-roll parameters to be $0 < \epsilon_1 < 0.032$ and $\epsilon_2 + 5.0 \epsilon_1 = 0.036…

Astrophysics · Physics 2009-11-07 Samuel M Leach , Andrew R Liddle

In this paper, we study a particular type of inflation by using non-local Friedman equations that are somehow derived from the zero levels of string field theory and express a tachyonic action. Then, we challenge it by further refining de…

High Energy Physics - Theory · Physics 2023-08-02 J. Sadeghi , B. Pourhassan , S. Noori Gashti , İ. Sakallı , M. R. Alipour

Flux couplings to string theory axions yield super-Planckian field ranges along which the axion potential energy grows. At the same time, other aspects of the physics remain essentially unchanged along these large displacements, respecting…

High Energy Physics - Theory · Physics 2014-09-30 Liam McAllister , Eva Silverstein , Alexander Westphal , Timm Wrase

The unwinding inflation mechanism is studied in a type IIB flux compactification where all moduli are stabilized using flux, non-perturbative effects, and the leading alpha' corrections of the large volume scenario. We consider the…

High Energy Physics - Theory · Physics 2017-12-14 Juan Diaz Dorronsoro , Marjorie Schillo

We examine a wide class of multi-field inflationary models based on fields that decay or stabilize during inflation in a staggered fashion. The fields driving assisted inflation are on flat, short stretches, before they encounter a sharp…

High Energy Physics - Theory · Physics 2009-03-27 Diana Battefeld , Thorsten Battefeld

We consider a class of multi-component hybrid inflation models whose evolution may be analytically solved under the slow-roll approximation. We call it multi-brid inflation (or $n$-brid inflation where $n$ stands for the number of inflaton…

Astrophysics · Physics 2009-10-09 Misao Sasaki

Bulk viscosity leads to negative pressure, which is a key ingredient for successful inflation. We build an inflationary model where the slow-roll of the inflaton field is driven by a viscous component instead of the flat potential commonly…

General Relativity and Quantum Cosmology · Physics 2025-04-15 Luca Visinelli

The scenario of constant-roll inflation is studied where the inflaton is a scalar field with modified kinetic term, known as non-canonical scalar field. This modification leads to some changes in the slow-roll parameters, and also by taking…

Cosmology and Nongalactic Astrophysics · Physics 2019-10-23 Abolhassan Mohammadi , Khaled Saaidi , Haidar Sheikhahmadi

We analyze string-theoretic large-field inflation in the regime of spontaneously-broken supergravity with conventional moduli stabilization by fluxes and non-perturbative effects. The main ingredient is a shift-symmetric Kahler potential,…

High Energy Physics - Theory · Physics 2014-08-26 Arthur Hebecker , Sebastian C. Kraus , Lukas T. Witkowski

We propose a class of single-field, slow-roll inflation models in which a typical number of $e$-folds can be extremely large. The key point is to introduce a very shallow local minimum near the top of the potential in a hilltop inflation…

High Energy Physics - Phenomenology · Physics 2019-12-16 Naoya Kitajima , Yuichiro Tada , Fuminobu Takahashi

We present constraints on how far single field inflation may depart from the familiar slow-roll paradigm. Considering a fast-roll regime while requiring a (near)-scale-invariant power spectrum introduces large self-interactions for the…

Cosmology and Nongalactic Astrophysics · Physics 2012-09-12 Johannes Noller

We discuss the possibility that inflation is driven by the sgoldstino, the superpartner of the goldstino. Unlike in generic supergravity scenarios, the sgoldstino decouples from all other fields in the theory, which allows for a simple and…

High Energy Physics - Theory · Physics 2013-12-03 Ana Achúcarro , Sander Mooij , Pablo Ortiz , Marieke Postma

We formalize the Hubble slow-roll formalism for inflationary dynamics in Randall-Sundrum Type II braneworld cosmologies, defining Hubble slow-roll parameters which can be used along with the Hamilton-Jacobi formalism. Focussing on the…

Astrophysics · Physics 2009-11-10 Erandy Ramirez , Andrew R. Liddle

The recently introduced swampland criterion for de Sitter (arXiv:1806.08362) can be viewed as a (hierarchically large) bound on the smallness of the slow roll parameter $\epsilon_V$. This leads us to consider the other slow roll parameter…

High Energy Physics - Theory · Physics 2021-08-12 Sumit K. Garg , Chethan Krishnan

We study F-term inflation in M-theory with and without five-brane moduli fields. We show the slow rolling condition is not satisfied in M-theory without five-brane moduli fields, but it can be satisfied in the case with non-vanishing…

High Energy Physics - Phenomenology · Physics 2009-10-31 S. M. Harun-or-Rashid , Tatsuo Kobayashi , Hitoshi Shimabukuro

We investigate the validity of effective field theory methods and the decoupling of heavy fields during inflation. Considering models of inflation in which the inflaton is coupled to a heavy (super-Hubble) degree of freedom initially in its…

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

Inflation is often described through the dynamics of a scalar field, slow-rolling in a suitable potential. Ultimately, this inflaton must be identified as the expectation value of a quantum field, evolving in a quantum effective potential.…

High Energy Physics - Phenomenology · Physics 2021-05-11 Jens O. Andersen , Magdalena Eriksson , Anders Tranberg

Inflationary models are usually based on dynamics of one or more scalar fields coupled to gravity. In this work we present a new class of inflationary models, gauge-flation or non-Abelian gauge field inflation, where slow-roll inflation is…

High Energy Physics - Phenomenology · Physics 2015-03-18 A. Maleknejad , M. M. Sheikh-Jabbari
‹ Prev 1 8 9 10 Next ›