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Related papers: Non-Gaussianity in rapid-turn multi-field inflatio…

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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

We explore extensions of hybrid inflationary models in the context of supersymmetric D-term inflation. We point out that a large variety of inflationary scenarios can be encountered when the field content is extended. It is not only…

High Energy Physics - Phenomenology · Physics 2008-11-26 Francis Bernardeau , Tristan Brunier

We consider a simple inflation model with a complex scalar field coupled to gravity non-minimally. Both the modulus and the angular directions of the complex scalar are slowly rolling, leading to two-field inflation. The modulus direction…

High Energy Physics - Phenomenology · Physics 2015-05-28 Jinn-Ouk Gong , Hyun Min Lee

While detection of the "local form" bispectrum of primordial perturbations would rule out all single-field inflation models, multi-field models would still be allowed. We show that multi-field models described by the $\delta N$ formalism…

General Relativity and Quantum Cosmology · Physics 2011-07-28 Naonori S. Sugiyama , Eiichiro Komatsu , Toshifumi Futamase

We compute the covariant three-point function near horizon-crossing for a system of slowly-rolling scalar fields during an inflationary epoch, allowing for an arbitrary field-space metric. We show explicitly how to compute its subsequent…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-10 Joseph Elliston , David Seery , Reza Tavakol

We study the effect of non-trivial sound speeds on local-type non-Gaussianity during multiple-field inflation. To this end, we consider a model of multiple-field DBI and use the deltaN formalism to track the super-horizon evolution of…

High Energy Physics - Theory · Physics 2012-08-07 Jon Emery , Gianmassimo Tasinato , David Wands

Recently multi-field inflation models that can produce large scalar fluctuations on small scales have drawn a lot of attention, primarily because they could lead to primordial black hole production and generation of large second-order…

Cosmology and Nongalactic Astrophysics · Physics 2023-09-21 Laura Iacconi , David J. Mulryne

We explore the superhorizon generation of large fnl of the local form in two field inflation. We calculate the two- and three-point observables in a general class of potentials which allow for an analytic treatment using the delta N…

Cosmology and Nongalactic Astrophysics · Physics 2011-06-17 Joel Meyers , Navin Sivanandam

We study the slow-roll inflation models, where the inflaton slow-rolls along a trajectory whose orthogonal directions are lifted by potentials with masses of order the Hubble parameter. In these models large non-Gaussianities can be…

Cosmology and Nongalactic Astrophysics · Physics 2010-04-06 Xingang Chen , Yi Wang

We compute analytic expressions for the non-linearity parameters characterizing the bi- and tri-spectrum of primordial curvature perturbations generated during an inflationary epoch of the early universe driven by an arbitrary number of…

High Energy Physics - Theory · Physics 2011-11-04 Diana Battefeld , Thorsten Battefeld

We generalize the Effective Field Theory of Inflation to include additional light scalar degrees of freedom that are in their vacuum at the time the modes of interest are crossing the horizon. In order to make the scalars light in a natural…

High Energy Physics - Theory · Physics 2015-05-19 Leonardo Senatore , Matias Zaldarriaga

In quasi-single field inflation models, massive isocurvature modes, that are coupled to the inflaton and have mass of order the Hubble parameter, can have nontrivial impacts on density perturbations, especially non-Gaussianities. We study a…

High Energy Physics - Theory · Physics 2010-05-07 Xingang Chen , Yi Wang

The theory and methodology is developed to compute the bispectrum in warm inflation, leading to results for the non-linearity parameter and the shape of the bispectrum. Particular attention is paid to the study of the bispectrum in the…

Cosmology and Nongalactic Astrophysics · Physics 2014-12-10 Mar Bastero-Gil , Arjun Berera , Ian G. Moss , Rudnei O. Ramos

Recent studies of inflation with multiple scalar fields have highlighted the importance of non-canonical kinetic terms in novel types of inflationary solutions. This motivates a thorough analysis of non-Gaussianities in this context, which…

High Energy Physics - Theory · Physics 2020-02-11 Sebastian Garcia-Saenz , Lucas Pinol , Sébastien Renaux-Petel

Inflation driven by a single, minimally coupled, slowly rolling field generically yields a negligible primordial non-Gaussianity. We discuss two distinct mechanisms by which a non-trivial potential can generate large non-Gaussianities.…

Astrophysics · Physics 2009-06-23 Xingang Chen , Richard Easther , Eugene A. Lim

Realistic models of high-energy physics include multiple scalar fields. Renormalization requires that the fields have nonminimal couplings to the spacetime Ricci curvature scalar, and the couplings can be large at the energy scales of…

Cosmology and Nongalactic Astrophysics · Physics 2013-03-21 David I. Kaiser , Edward A. Mazenc , Evangelos I. Sfakianakis

Multiple inflation is a model based on N=1 supergravity wherein there are sudden changes in the mass of the inflaton because it couples to 'flat direction' scalar fields which undergo symmetry breaking phase transitions as the universe…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Shaun Hotchkiss , Subir Sarkar

We perform the analysis of the trispectrum of curvature perturbations generated by the interactions characterizing a general theory of single-field inflation obtained by effective field theory methods. We find that curvature-generated…

Cosmology and Nongalactic Astrophysics · Physics 2011-01-27 Nicola Bartolo , Matteo Fasiello , Sabino Matarrese , Antonio Riotto

The effect of self-interactions of heavy scalar fields during inflation on the primordial non-Gaussianity is studied. We take a specific constant-turn quasi-single field inflation as an example. We derive an effective theory with emphasis…

High Energy Physics - Theory · Physics 2015-06-16 Jinn-Ouk Gong , Shi Pi , Misao Sasaki

Primordial non-Gaussianities from multi-field inflation are a leading target for cosmological observations, because of the possible large correlations generated between long and short distances. These signatures are captured by the local…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-31 Dong-Gang Wang , Guilherme L. Pimentel , Ana Achúcarro