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Related papers: Probing Inflation with Precision Bispectra

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We investigate the observational signatures of many-field inflation and present analytic expressions for the spectral index as a function of the prior. For a given prior we employ the central limit theorem and the horizon crossing…

Cosmology and Nongalactic Astrophysics · Physics 2020-04-29 Perseas Christodoulidis , Diederik Roest , Robert Rosati

The family of primitive binary substitutions defined by $1 \mapsto 0 \mapsto 0 1^m$ with $m\in\mathbb{N}$ is investigated. The spectral type of the corresponding diffraction measure is analysed for its geometric realisation with prototiles…

Dynamical Systems · Mathematics 2018-07-03 Michael Baake , Uwe Grimm , Neil Manibo

We compute the spectral index for scalar perturbations generated in a primordial inflationary model. In this model, the transition of the inflationary phase to the radiative era is achieved through the decay of the cosmological term leading…

High Energy Physics - Theory · Physics 2009-11-07 Julio C. Fabris , Philippe Spindel

We derive a direct correlation between the power spectrum and bispectrum of the primordial curvature perturbation in terms of the Goldstone mode based on the effective field theory approach to inflation. We show examples of correlated…

Cosmology and Nongalactic Astrophysics · Physics 2017-04-19 Jinn-Ouk Gong , Masahide Yamaguchi

One of the fundamental questions in inflation is how to characterize the structure of different types of models in the field theoretic landscape. Proposals in this direction include attempts to directly characterize the formal structure of…

Cosmology and Nongalactic Astrophysics · Physics 2023-09-12 Monika Lynker , Rolf Schimmrigk

The slow-roll inflation for a single scalar field that couples to the Gauss-Bonnet (GB) term represents an important higher-order curvature correction inspired by string theory. With the arrival of the era of precision cosmology, it is…

General Relativity and Quantum Cosmology · Physics 2018-05-09 Qiang Wu , Tao Zhu , Anzhong Wang

We extend the transport framework for numerically evaluating the power spectrum and bispectrum in multi-field inflation to the case of a curved field-space metric. This method naturally accounts for all sub- and super-horizon tree level…

Cosmology and Nongalactic Astrophysics · Physics 2018-01-26 John W. Ronayne , David J. Mulryne

Taking field theory seriously, inflation model-building is difficult but not impossible. The observed value of the spectral index of the adiabatic density perturbation is starting to discriminate between models, and may well pick out a…

High Energy Physics - Phenomenology · Physics 2009-10-31 David H Lyth

We present a new, exact scalar field cosmology for which the spectrum of scalar (density) perturbations can be calculated exactly. We use this exact result to the probe the accuracy of approximate calculations of the perturbation spectrum.

Astrophysics · Physics 2009-10-28 Richard Easther

The problem of causal inference is to determine if a given probability distribution on observed variables is compatible with some causal structure. The difficult case is when the causal structure includes latent variables. We here introduce…

Quantum Physics · Physics 2019-07-24 Elie Wolfe , Robert W. Spekkens , Tobias Fritz

We propose a model of inflation with a suitable potential for a single scalar field which falls in the wide class of hilltop inflation. We derive the analytical expressions for most of the physical quantities related to inflation and show…

High Energy Physics - Theory · Physics 2010-01-28 Barun Kumar Pal , Supratik Pal , B. Basu

The early Universe inflation is well known as a promising theory to explain the origin of large scale structure of the Universe, a causal theory for the origin of primordial density fluctuations which may explain the observed density…

Astrophysics · Physics 2007-05-23 Xin-he Meng

We present primordial non-Gaussianity predictions from a new high-precision code for simulating axion-U(1) inflation on a discrete lattice. We measure the primordial scalar curvature power spectrum and bispectrum from our simulations,…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-26 Drew Jamieson , Angelo Caravano , Eiichiro Komatsu

Multifield models of inflation with nonminimal couplings are in excellent agreement with the recent results from {\it Planck}. Across a broad range of couplings and initial conditions, such models evolve along an effectively single-field…

Cosmology and Nongalactic Astrophysics · Physics 2014-01-08 David I. Kaiser , Evangelos I. Sfakianakis

In this thesis we will primarily demonstrate how additional scalar degrees of freedom - which are motivated from many high-energy embeddings - open up new observational windows onto the physics of inflation. We construct a Bayesian…

Cosmology and Nongalactic Astrophysics · Physics 2019-06-11 Robert J. Hardwick

We propose a new approach to investigate inflation in a model-independent way, and in particular to elaborate the involved observables, through the introduction of the "scale factor potential". Through its use one can immediately determine…

General Relativity and Quantum Cosmology · Physics 2020-06-02 David Benisty , Eduardo I. Guendelman , Emmanuel N. Saridakis

This paper presents a method for obtaining an analytic expression for the density function of observables in multifield models of inflation with sum-separable potentials. The most striking result is that the density function in general…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Jonathan Frazer

We consider the spectrum of primordial fluctuations produced by inflationary models where the inflaton potential is the sum of two exponential terms. A wide range of spectra result, with the only constraint being that the scalar spectrum…

Astrophysics · Physics 2009-09-25 Richard Easther

Inflation in cosmology is a specific stage preceding the Big Bang, aimed at solving both old background problems and new perturbation issues. Single-field inflation is a candidate to illustrate the picture of the initial universe, and…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-21 Guanqiao Liu

We revisit inflation with non-canonical scalar fields by applying deformed-steepness exponential potentials. We show that the resulting scenario can lead to inflationary observables, and in particular to scalar spectral index and…

General Relativity and Quantum Cosmology · Physics 2021-08-24 Smaragda Lola , Andreas Lymperis , Emmanuel N. Saridakis