English
Related papers

Related papers: On the full quantum trispectrum in multi-field DBI…

200 papers

We compute the full bispectra, namely both auto- and cross- bispectra, of primordial curvature and tensor perturbations in the most general single-field inflation model whose scalar and gravitational equations of motion are of second order.…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-20 Xian Gao , Tsutomu Kobayashi , Maresuke Shiraishi , Masahide Yamaguchi , Jun'ichi Yokoyama , Shuichiro Yokoyama

Any one-field inflation is actually realized in a multifield configuration because the inflaton must have couplings with other fields to reheat the universe and is coupled to all other fields at least gravitationally. In all single inflaton…

High Energy Physics - Phenomenology · Physics 2009-11-11 Masahide Yamaguchi , Jun'ichi Yokoyama

We have studied primordial non-Gaussian features from a model of potential driven single field DBI Galileon inflation. We have computed the bispectrum from the three point correlation function considering all possible cross correlation…

High Energy Physics - Theory · Physics 2015-06-08 Sayantan Choudhury , Supratik Pal

Soft limits of $N$-point correlation functions, in which one wavenumber is much smaller than the others, play a special role in constraining the physics of inflation. Anisotropic sources such as a vector field during inflation generate…

Cosmology and Nongalactic Astrophysics · Physics 2014-05-12 Maresuke Shiraishi , Eiichiro Komatsu , Marco Peloso

The methods of effective field theory are used to study generic theories of inflation with a single inflaton field and to perform a general analysis of the associated non-Gaussianities. We investigate the amplitudes and shapes of the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Nicola Bartolo , Matteo Fasiello , Sabino Matarrese , Antonio Riotto

We calculate the power spectra of primordial curvature and isocurvature perturbations from a general two field inflation model at next-to-leading order correction in a slow-roll expansion. In particular we calculate the spectral indices to…

Astrophysics · Physics 2009-11-11 Christian T. Byrnes , David Wands

If time-dependent disruptions from slow-roll occur during inflation, the correlation functions of the primordial curvature perturbation should have scale-dependent features, a case which is marginally supported from the cosmic microwave…

Cosmology and Nongalactic Astrophysics · Physics 2018-06-04 Jinn-Ouk Gong , Gonzalo A. Palma , Spyros Sypsas

We study the effects of a general type of features of the inflaton potential on the spectrum and bispectrum of primordial curvature perturbations. These features correspond to a discontinuity in the $n$-th order derivative of the potential…

Cosmology and Nongalactic Astrophysics · Physics 2015-08-25 Alexander Gallego Cadavid

We study multi-field DBI inflation models with a waterfall phase transition. This transition happens for a D3 brane moving in the warped conifold if there is an instability along angular directions. The transition converts the angular…

Cosmology and Nongalactic Astrophysics · Physics 2012-11-29 Taichi Kidani , Kazuya Koyama , Shuntaro Mizuno

Supersymmetry plays a fundamental role in the radiative stability of many inflationary models. Spontaneous breaking of the symmetry inevitably leads to fields with masses of order the Hubble scale during inflation. When these fields couple…

High Energy Physics - Theory · Physics 2013-05-30 Daniel Baumann , Daniel Green

We reconsider the observed CMB dipolar asymmetry in the context of open inflation, where a supercurvature mode might survive the bubble nucleation. If such a supercurvature mode modulates the amplitude of the curvature power spectrum, it…

Cosmology and Nongalactic Astrophysics · Physics 2016-12-21 Christian Byrnes , Guillem Domènech , Misao Sasaki , Tomo Takahashi

We study the emergence of quantum entanglement in multi-field inflation. In this scenario, the perturbations of one field contribute to the observable curvature perturbation, while multi-field dynamics with the other fields affect the…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-19 Nadia Bolis , Tomohiro Fujita , Shuntaro Mizuno , Shinji Mukohyama

In this letter we study adiabatic and isocurvature perturbations in the frame of inflation with multiple sound speeds involved. We suggest this scenario can be realized by a number of generalized scalar fields with arbitrary kinetic forms.…

High Energy Physics - Theory · Physics 2010-12-17 Yi-Fu Cai , Hai-Ying Xia

We study single-field inflationary models with steep step-like features in the potential that lead to the temporary violation of the slow-roll conditions during the evolution of the inflaton. These features enhance the power spectrum of the…

Cosmology and Nongalactic Astrophysics · Physics 2022-02-18 I. Dalianis , G. P. Kodaxis , I. D. Stamou , N. Tetradis , A. Tsigkas-Kouvelis

We consider small-field models which invoke the usual framework for the effective field theory, and large-field models which go beyond that. Present and future possibilities for discriminating between the models are assessed, on the…

Astrophysics · Physics 2015-06-24 Laila Alabidi , David Lyth

We analyze the spectrum of density perturbations generated in models of the recently discovered "D-cceleration" mechanism of inflation. In this scenario, strong coupling quantum field theoretic effects sum to provide a DBI-like action for…

High Energy Physics - Theory · Physics 2009-11-10 Mohsen Alishahiha , Eva Silverstein , David Tong

We develop an approach for linking the power spectra, bispectrum, and trispectrum to the geometric and kinematical features of multifield inflationary Lagrangians. Our geometric approach can also be useful in determining when a complicated…

Cosmology and Nongalactic Astrophysics · Physics 2012-11-26 Courtney M. Peterson , Max Tegmark

We study the degeneracy of the primordial spectrum and bispectrum of the curvature perturbation in single field inflationary models with a class of features in the inflaton potential. The feature we consider is a discontinuous change in the…

Cosmology and Nongalactic Astrophysics · Physics 2018-06-07 Alexander Gallego Cadavid , Antonio Enea Romano , Misao Sasaki

We study multifield aspects of Dirac-Born-Infeld (DBI) inflation. More specifically, we consider an inflationary phase driven by the radial motion of a D-brane in a conical throat and determine how the D-brane fluctuations in the angular…

High Energy Physics - Theory · Physics 2014-11-20 Sébastien Renaux-Petel

Multi-field inflation can be inherently non-predictive, with the exception of models with strong attractors. In this work, we focus on models with multiple scalar fields that are non-minimally coupled to the space-time Ricci curvature…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-18 Perseas Christodoulidis , Robert Rosati , Evangelos I. Sfakianakis