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Constraining inflationary models with high precision bispectra across broad parameter ranges is a challenging task, requiring intensive computations at all stages, first, predicting the primordial inflation bispectrum from quantum field…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-29 Bowei Zhang , E. P. S. Shellard , James R. Fergusson

We propose a new approach for calculating the curvature perturbations produced during inflation in the stochastic formalism. In our formalism, the fluctuations of the e-foldings are directly calculated without perturbatively expanding the…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-06 Tomohiro Fujita , Masahiro Kawasaki , Yuichiro Tada , Tomohiro Takesako

We study the non-Gaussianity generated during multiple-field inflation. We provide an exact expression for the bispectrum parameter f_NL which is valid beyond the slow-roll regime, valid for certain classes of inflationary models. We then…

Cosmology and Nongalactic Astrophysics · Physics 2011-11-04 Christian T. Byrnes , Gianmassimo Tasinato

We investigate inflationary scenarios driven by a class of potentials which are similar in form to those that arise in certain minimal supersymmetric extensions of the standard model. We find that these potentials allow a brief period of…

Detailed analyses of the WMAP data indicate possible oscillatory features in the primordial curvature perturbation, which moreover appears to be suppressed beyond the present Hubble radius. Such deviations from the usual inflationary…

Astrophysics · Physics 2014-11-18 Paul Hunt , Subir Sarkar

If we posit the validity of the consistency relations, the tensor spectral index and the relative amplitude of the scalar and tensor power spectra are both fixed by a single slow roll parameter. The physics of the protoinflationary…

High Energy Physics - Theory · Physics 2015-06-19 Massimo Giovannini

We investigate radiative corrections to the inflaton potential from heavy fields undergoing a fast-roll phase transition. We find that a logarithmic one-loop correction to the inflaton potential involving this field can induce a temporary…

High Energy Physics - Theory · Physics 2015-06-16 Rajeev Kumar Jain , McCullen Sandora , Martin S. Sloth

We study the primordial bispectrum of curvature perturbation in the uniform- density slicing generated by the interaction between the inflaton and isotropic background gauge fields. We derive the action up to cubic order in perturbation and…

Cosmology and Nongalactic Astrophysics · Physics 2013-06-05 Hiroyuki Funakoshi , Kei Yamamoto

Cosmic microwave background studies of non-Gaussianity involving higher-order multispectra can distinguish between early universe theories that predict nearly identical power spectra. However, the recovery of higher-order multispectra is…

Cosmology and Nongalactic Astrophysics · Physics 2011-07-26 Dipak Munshi , Alan Heavens , Asantha Cooray , Joseph Smidt , Peter Coles , Paolo Serra

We develop analytic and numerical techniques for studying the statistics of slow-roll inflation in random Gaussian landscapes. As an illustration of these techniques, we analyze small-field inflation in a one-dimensional landscape. We…

High Energy Physics - Theory · Physics 2017-06-14 Ali Masoumi , Alexander Vilenkin , Masaki Yamada

In 2004, Creminelli and Zaldarriaga proposed a consistency relation for the primordial curvature perturbation of all single-field inflation models; it related the bispectrum in the squeezed limit to the spectral tilt. We have developed a…

Cosmology and Nongalactic Astrophysics · Physics 2010-12-21 Jonathan Ganc , Eiichiro Komatsu

The claimed detection of the BICEP2 experiment on the primordial B-mode of cosmic microwave background polarization suggests that cosmic inflation possibly takes place at the energy around the grand unified theory scale given a constraint…

Cosmology and Nongalactic Astrophysics · Physics 2014-08-22 Phongpichit Channuie , Khamphee Karwan

Rapid-turn slow-roll inflationary trajectories have been shown to be an attractor in two-field models, provided the turn rate is near constant and larger than the slow-roll parameters. These trajectories can produce primordial spectra…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-06 Raul Wolters , Oksana Iarygina , Ana Achucarro

Recent observations suggest that the spectral index of the primordial perturbations is very close to unity, as expected in models of slow roll inflation. It is still possible for such models to produce spectra which are scale dependent. We…

Astrophysics · Physics 2009-09-02 Scott Dodelson , Ewan Stewart

We consider the constant-roll condition in the model of the inflaton nonminimal coupling to the Gauss-Bonnet term. By assuming the first Gauss-Bonnet flow parameter $\delta_1$ is a constant, we discuss the constant-roll inflation with…

General Relativity and Quantum Cosmology · Physics 2020-12-02 Tie-Jun Gao

Solid inflation is an effective field theory of inflation in which isotropy and homogeneity are accomplished via a specific combination of anisotropic sources (three scalar fields that individually break isotropy). This results in specific…

Cosmology and Nongalactic Astrophysics · Physics 2015-09-11 Nicola Bartolo , Marco Peloso , Angelo Ricciardone , Caner Unal

Many, if not most, inflationary models predict the power-law index of the spectrum of density perturbations is close to one, though not precisely equal to one, |n-1| \sim O(0.1), implying that the spectrum of density perturbations is…

Astrophysics · Physics 2009-10-31 Dragan Huterer , Michael S. Turner

We present a new efficient method for computing the non-linearity parameters of the higher order correlation functions of local type curvature perturbations in inflation models having a $\cal N$-component scalar field, focusing on the…

Astrophysics · Physics 2014-11-18 Shuichiro Yokoyama , Teruaki Suyama , Takahiro Tanaka

We present a perturbative approach for studying inflation models with soft departures from scale free spectra of the power law model. In the perturbed power law (PPL) approach one obtains at the leading order both the scalar and tensor…

Cosmology and Nongalactic Astrophysics · Physics 2011-03-18 Minu Joy , Tarun Souradeep

This paper proposes to correct the rolling shutter (RS) distorted images by estimating the distortion flow from the global shutter (GS) to RS directly. Existing methods usually perform correction using the undistortion flow from the RS to…

Computer Vision and Pattern Recognition · Computer Science 2024-04-10 Mingdeng Cao , Sidi Yang , Yujiu Yang , Yinqiang Zheng
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