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We derive consistency conditions for sustained slow roll and rapid turn inflation in two-field cosmological models with oriented scalar field space, which imply that inflationary models with field-space trajectories of this type are…

High Energy Physics - Theory · Physics 2023-05-18 Lilia Anguelova , Calin Iuliu Lazaroiu

In presence of Gauss-Bonnet corrections, we study anisotropic inflation aided by a massless $SU(2)$ gauge field where both the gauge field and the Gauss-Bonnet term are non-minimally coupled to the inflaton. In this scenario, under…

High Energy Physics - Theory · Physics 2017-01-18 Sayantani Lahiri

We investigate the axion inflation model derived by poly-instanton effects in type II superstring theories. Poly-instanton effects are instanton effects corrected by another instanton and it can generate the modulus-axion potential with the…

High Energy Physics - Phenomenology · Physics 2017-07-19 Tatsuo Kobayashi , Shohei Uemura , Junji Yamamoto

We propose a new inflationary scenario in type IIB Calabi-Yau compactifications, where the inflaton is a K\"ahler modulus parameterising the volume of an internal four-cycle. The inflaton potential is generated via poly-instanton…

High Energy Physics - Theory · Physics 2015-06-03 Michele Cicoli , Francisco G. Pedro , Gianmassimo Tasinato

We consider a model of inflation in which the inflaton field is a rolling axion with a potential which is flat enough to support an intermediate phase of USR inflation. Because of the Chern-Simons interaction, one polarization of the gauge…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-04 Alireza Talebian , Hassan Firouzjahi

We study the effects of the non-attractor initial conditions for the canonical single-field inflation. The non-attractor stage can last only several $e$-folding numbers, and should be followed by hilltop inflation. This two-stage evolution…

Cosmology and Nongalactic Astrophysics · Physics 2016-10-13 Yi-Fu Cai , Jinn-Ouk Gong , Dong-Gang Wang , Ziwei Wang

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 draw attention to the possibility that inflation (i.e. accelerated expansion) might continue after the end of slow roll, during a period of fast oscillations of the inflaton field \phi . This phenomenon takes place when a mild…

General Relativity and Quantum Cosmology · Physics 2009-10-30 Thibault Damour , Viatcheslav F. Mukhanov

We study the stochastic formalism of inflation beyond the usual slow-roll approximation. We verify that the assumptions on which the stochastic formalism relies still hold even far from the slow-roll attractor. This includes demonstrating…

Cosmology and Nongalactic Astrophysics · Physics 2019-11-05 Chris Pattison , Vincent Vennin , Hooshyar Assadullahi , David Wands

We study the dual 3d Euclidean RG flow of single-field slow-roll Inflation using the postulates of the dS/CFT correspondence. For that purpose we solve for the inflationary fluctuation at all times using a matching procedure between two…

High Energy Physics - Theory · Physics 2015-06-17 Uri Kol

We find constraints on inflationary dynamics that yield a large local bispectrum and/or trispectrum during two-field slow-roll inflation. This leads to simple relations between the non-Gaussianity parameters, simplifying the…

Cosmology and Nongalactic Astrophysics · Physics 2013-02-21 Joseph Elliston

Gauge-flation, non-Abelian gauge field inflation, which was introduced in arXiv:1102.1513 and analyzed more thoroughly in arXiv:1102.1932, is a model of inflation driven by non-Abelian gauge fields minimally coupled to Einstein gravity. In…

High Energy Physics - Theory · Physics 2015-06-04 M. M. Sheikh-Jabbari

We present a new model of large field inflation along a winding trajectory in the field space of two axionic fields, where the 'axions' originate from the complex structure moduli sector of a Calabi-Yau 3-fold at large complex structure.…

High Energy Physics - Theory · Physics 2015-08-05 Arthur Hebecker , Patrick Mangat , Fabrizio Rompineve , Lukas T. Witkowski

We study the non-Gaussian features in single-field slow-roll inflationary scenario where inflation is preceded by a radiation era. In such a scenario both bispectrum and trispectrum non-Gaussianities are enhanced. Interestingly, the…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-11 Suratna Das

Inflationary models driven by a large number of axion fields are discussed in the context of type IIB compactifications with N=1 supersymmetry. The inflatons arise as the scalar modes of the R-R two-forms evaluated on vanishing two-cycles…

High Energy Physics - Theory · Physics 2008-06-13 Thomas W. Grimm

We study an inflation model that inflaton field is non-minimally coupled to the induced scalar curvature on the Randall-Sundrum (RS) II brane. We investigate the effects of the non-minimal coupling on the inflationary dynamics of this…

General Relativity and Quantum Cosmology · Physics 2014-11-20 Kourosh Nozari , M. Shoukrani

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

These notes present a detailed introduction to Maldacena's calculation of the three-point function generated by the simplest class of inflationary models: those with a single inflaton field whose potential satisfies the slow-roll conditions…

Cosmology and Nongalactic Astrophysics · Physics 2014-06-02 Hael Collins

In this paper we analyze scalar gravitational perturbations on a Robertson-Walker background in the presence of multiple scalar fields that take values on a (geometrically non-trivial) field manifold during slow-roll inflation. For this…

High Energy Physics - Phenomenology · Physics 2007-05-23 S. Groot Nibbelink , B. J. W. van Tent

Theories beyond the standard model such as string theory motivate low energy effective field theories with several scalar fields which are not only coupled through a potential but also through their kinetic terms. For such theories we…

Astrophysics · Physics 2010-10-27 Ki-Young Choi , Lisa M. H. Hall , Carsten van de Bruck