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Related papers: Squeezed tensor non-Gaussianity in non-attractor i…

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Massive bigravity, a theoretically consistent modification of general relativity with an additional dynamical rank two tensor, successfully describes the observed accelerated expansion of the Universe without a cosmological constant. Recent…

Cosmology and Nongalactic Astrophysics · Physics 2015-08-12 Matthew Johnson , Alexandra Terrana

We completely clarify the feature of primordial non-Gaussianities of tensor perturbations in generalized G-inflation, i.e., the most general single-field inflation model with second order field equations. It is shown that the most general…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Xian Gao , Tsutomu Kobayashi , Masahide Yamaguchi , Jun'ichi Yokoyama

We investigate small-scale signatures of the inflationary particle content. We consider the case of a light spin-2 particle sourcing primordial gravitational waves by employing an effective field theory description. Upon allowing…

Cosmology and Nongalactic Astrophysics · Physics 2020-12-08 Laura Iacconi , Matteo Fasiello , Hooshyar Assadullahi , David Wands

Cross-correlations between Cosmic Microwave Background (CMB) temperature and polarization anisotropies and $\mu$-spectral distortions have been considered to measure (squeezed) primordial scalar bispectra in a range of scales inaccessible…

Cosmology and Nongalactic Astrophysics · Physics 2022-02-04 Giorgio Orlando , P. Daniel Meerburg , Subodh P. Patil

Most, if not all, scalar-tensor theories are equivalent to General Relativity with a disformally coupled matter sector. In extra-dimensional theories such a coupling can be understood as a result of induction of the metric on a brane that…

Cosmology and Nongalactic Astrophysics · Physics 2017-02-22 Carsten van de Bruck , Tomi Koivisto , Chris Longden

We discuss how primordial non-Gaussianity of the curvature perturbation helps to constrain models of the early universe. Observations are consistent with Gaussian initial conditions, compatible with the predictions of the simplest models of…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-26 Christian T. Byrnes

A major goal of cosmology is to understand the nature of the field(s) which drove primordial Inflation. Through future observations, the statistics of large-scale structure will allow us to probe primordial non-Gaussianity of the curvature…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-14 Dionysios Karagiannis , Roy Maartens , Shun Saito , José Fonseca , Stefano Camera , Chris Clarkson

We investigate non-Gaussianity in general multiple-field inflation using the formalism we developed in earlier papers. We use a perturbative expansion of the non-linear equations to calculate the three-point correlator of the curvature…

Astrophysics · Physics 2009-11-13 G. I. Rigopoulos , E. P. S. Shellard , B. J. W. van Tent

This article investigates the generation of non-Gaussianity during inflation. In the context of multi-field inflation, we detail a mechanism that can create significant primordial non-Gaussianities in the adiabatic mode while preserving the…

High Energy Physics - Phenomenology · Physics 2009-11-07 Francis Bernardeau , Jean-Philippe Uzan

We analyze quantum corrections on the naive $\phi^4$-Inflation. These typically lead to an inflaton potential which carries a non-integer power of the field. We consider both minimal and non-minimal couplings to gravity. For the latter case…

High Energy Physics - Phenomenology · Physics 2014-09-03 Jakob Joergensen , Francesco Sannino , Ole Svendsen

Scalar metric fluctuations generically source a spectrum of gravitational waves at second order in perturbation theory, poising gravitational wave experiments as potentially powerful probes of the small-scale curvature power spectrum. We…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-20 Peter Adshead , Kaloian D. Lozanov , Zachary J. Weiner

We study the axionic inflation with a modulated potential and examine if the primordial tensor power spectrum exhibits oscillatory feature, which is testable with future space-based gravitational wave experiments such as DECIGO and BBO. In…

Cosmology and Nongalactic Astrophysics · Physics 2016-09-07 Ippei Obata , Jiro Soda

Why is non-Gaussianity interesting? One of generic predictions from inflationary scenarios is that primordial fluctuations are exactly Gaussian in linear order; however, the non-linearity in the inflation will produce weak non-Gaussianity.…

Astrophysics · Physics 2017-08-23 Eiichiro Komatsu , David N. Spergel

We give new constraints on small-scale non-Gaussianity of primordial curvature perturbations by the use of anisotropies in acoustic reheating. Mixing of local thermal or local kinetic equilibrium systems with different temperatures yields a…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Atsushi Naruko , Atsuhisa Ota , Masahide Yamaguchi

We describe a general scenario where primordial non-Gaussian curvature perturbations are generated in models with extra scalar fields. The extra scalars communicate to the inflaton sector mainly through the tachyonic (waterfall) field…

High Energy Physics - Theory · Physics 2008-11-26 Bhaskar Dutta , Jason Kumar , Louis Leblond

In this work, we present a method for implementing the $\delta N$ formalism to study the primordial non-Gaussianity produced in multiple three-form field inflation. Using a dual description relating three-form fields to noncanonical scalar…

Cosmology and Nongalactic Astrophysics · Physics 2016-11-09 K. Sravan Kumar , David J. Mulryne , Nelson J. Nunes , João Marto , Paulo Vargas Moniz

In this paper, we compute the inflationary trispectrum of primordial gauge fields generated through the scalar and tensor exchanges in models with spectator $U(1)$ gauge fields which are kinetically coupled to the inflaton. Focusing on the…

High Energy Physics - Theory · Physics 2025-09-16 P. Jishnu Sai , S. R. Haridev , Rajeev Kumar Jain

We present the model-independent studies of non attractor inflation in the context of effective field theory (EFT) of inflation. Within the EFT approach two independent branches of non-attractor inflation solutions are discovered in which a…

High Energy Physics - Theory · Physics 2015-08-06 Mohammad Akhshik , Hassan Firouzjahi , Sadra Jazayeri

We study the non-Gaussianities generated by light axions, or compact scalar fields, during inflation. To correctly calculate their impact on primordial statistics, we will argue that it is necessary to account for the periodicity, or gauge…

High Energy Physics - Theory · Physics 2025-10-28 Priyesh Chakraborty

We analyze primordial non-Gaussianity in single field inflationary models when the tensor/scalar ratio is large. Our results show that detectable levels of non-Gaussianity $f_{NL} \sim 50$ are still possible in the simplest class of models…

Cosmology and Nongalactic Astrophysics · Physics 2014-09-19 Guido D'Amico , Matthew Kleban