English
Related papers

Related papers: Multifield Inflation after Planck: The Case for No…

200 papers

In this work, we revisit the Witten-O'Raifeartaigh model of inflation, in which the potential takes a $\operatorname{log}^2(\phi/M)$ form, when the scalar field is non-minimally coupled to gravity. We investigate the impact of the coupling…

Cosmology and Nongalactic Astrophysics · Physics 2022-08-10 F. B. M. dos Santos , R. Silva

Erickcek, Kamionkowski and Carroll proposed in 2008 that the dipole modulation of the CMB could be due to a very large scale perturbation of the field $\phi$ causing the primordial curvature perturbation. We repeat their calculation using…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 David H. Lyth

Space-based missions studying the cosmic microwave background (CMB) have progressively refined the parameter space in conventional models of inflation shortly ($\sim 10^{-37}$ seconds) after the big bang. While most inflationary scenarios…

Cosmology and Nongalactic Astrophysics · Physics 2024-04-18 Jingwei Liu , Fulvio Melia

We perform a Bayesian model comparison for scenarios within the quadratic curvaton model, determining the degree to which both are disfavoured with respect to the $\Lambda$CDM concordance model and single-field quadratic inflation, using…

Cosmology and Nongalactic Astrophysics · Physics 2015-08-05 Robert J. Hardwick , Christian T. Byrnes

Bayesian inference techniques are used to investigate situations where an additional light scalar field is present during inflation and reheating. This includes (but is not limited to) curvaton-type models. We design a numerical pipeline…

Cosmology and Nongalactic Astrophysics · Physics 2017-09-13 Vincent Vennin , Kazuya Koyama , David Wands

We calculate the primordial spectrum of scalar perturbations of the 3-form inflation and we find that the curvature perturbations decay at late times. As as result, although a non-minimally coupled massive 3-form field may drive inflation…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-29 Cristiano Germani , Alex Kehagias

We perform a Markov Chain Monte Carlo (MCMC) analysis of a simple yet generic multifield inflation model characterized by two scalar fields coupled to each other and nonminimally coupled to gravity, fit to Planck 2018 cosmic microwave…

Cosmology and Nongalactic Astrophysics · Physics 2023-08-04 Wenzer Qin , Sarah R. Geller , Shyam Balaji , Evan McDonough , David I. Kaiser

The oscillating inflation model recently proposed by Damour and Mukhanov is investigated with a non-minimal coupling. Numerical study confirms an inflationary behavior and the density perturbation is obtained. A successful inflation…

High Energy Physics - Theory · Physics 2019-08-17 Jae-weon Lee , Seoktae Koh , Chanyong Park , Sang Jin Sin , Chul H. Lee

The presence of multiple fields during inflation might seed a detectable amount of non-Gaussianity in the curvature perturbations, which in turn becomes observable in present data sets like the cosmic microwave background (CMB) or the large…

Cosmology and Nongalactic Astrophysics · Physics 2015-08-27 Sebastian Dorn , Erandy Ramirez , Kerstin E. Kunze , Stefan Hofmann , Torsten A. Enßlin

Recent years have seen the introduction of various multi-field inflationary scenarios in which the curvature and geodesics of the scalar manifold play a crucial role. We outline a simple description that unifies these different proposals…

General Relativity and Quantum Cosmology · Physics 2020-08-14 Perseas Christodoulidis , Diederik Roest , Evangelos I. Sfakianakis

Motivated by the result of Planck+BICEP/Keck recently released, we investigate the consistency of the multi-field inflation models in terms of the spectral index $n_s$ and the tensor-to-scalar ratio $r$. In this study, we focus on…

Cosmology and Nongalactic Astrophysics · Physics 2022-08-03 Yukiyoshi Morishita , Tomo Takahashi , Shuichiro Yokoyama

We develop an integral form for the bispectrum in general single-field inflation whose domain of validity includes models of inflation where the background evolution is not constrained to be slowly varying everywhere. Our integral form…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-18 Peter Adshead , Wayne Hu , V Miranda

The primordial power spectrum informs the possible inflationary histories of our universe. Given a power spectrum, the ensuing cosmic microwave background is calculated and compared to the observed one. Thus, one focus of modern cosmology…

Cosmology and Nongalactic Astrophysics · Physics 2022-01-25 Ira Wolfson

We analyse the multifield behaviour in D-brane inflation when contributions from the bulk are taken into account. For this purpose, we study a large number of realisations of the potential; we find the nature of the inflationary trajectory…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Mafalda Dias , Jonathan Frazer , Andrew R. Liddle

In inflationary scenarios with more than one scalar field, inflation may proceed even if each of the individual fields has a potential too steep for that field to sustain inflation on its own. We show that scalar fields with exponential…

Astrophysics · Physics 2010-01-06 Andrew R Liddle , Anupam Mazumdar , Franz E Schunck

We briefly summarize the impact of the recent Planck measurements for string inflationary models, and outline what might be expected to be learned in the near future from the expected improvement in sensitivity to the primordial…

High Energy Physics - Theory · Physics 2015-06-16 C. P. Burgess , M. Cicoli , F. Quevedo

Because the inflationary mechanism is extremely sensitive to UV-physics, the construction of theoretically robust models of inflation provides a unique window on Planck-scale physics. We review efforts to use an axion with a shift symmetry…

High Energy Physics - Theory · Physics 2015-06-15 Enrico Pajer , Marco Peloso

We investigate the inflationary universe in a theory where two scalar fields non-minimally coupling to the scalar curvature and an extra $R^2$ term exist and the conformal invariance is broken. In particular, the slow-roll inflation is…

High Energy Physics - Theory · Physics 2016-03-01 Kazuharu Bamba

We study the evolution of regions of space with various initial field values for a simple theory that can support hybrid inflation. Only very narrow domains within the range of initial field values below the Planck scale lead to the onset…

Astrophysics · Physics 2009-06-19 N. Tetradis

In solid inflation the single field non-Gaussianity consistency condition is violated. As a result, the long tensor perturbation induces observable clustering fossils in the form of quardupole anisotropy in large scale structure power…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Mohammad Akhshik