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200 papers

Motivated by the recent `Higgs-inflation' scenario based on a single inflaton field, we consider more generic two-field inflation with non-minimal coupling term. The generic analytic expressions are derived for cosmological observables with…

High Energy Physics - Phenomenology · Physics 2015-03-13 Jinsu Kim , Yoonbai Kim , Seong Chan Park

A new family of inflation models is introduced and studied. The models are characterised by a scalar potential which, far from the origin, approaches an inflationary plateau in a power-law manner, while near the origin becomes monomial, as…

High Energy Physics - Phenomenology · Physics 2015-11-20 Konstantinos Dimopoulos

We consider models of chaotic inflation driven by the real parts of a conjugate pair of Higgs superfields involved in the spontaneous breaking of a grand unification symmetry at a scale assuming its Supersymmetric value. Employing Kaehler…

High Energy Physics - Phenomenology · Physics 2016-11-22 C. Pallis

We place observational constraints on slow-variation single-field inflationary models by carrying out the cosmological Monte Carlo simulation with the recent data of Planck combined with the WMAP large-angle polarization, baryon acoustic…

Cosmology and Nongalactic Astrophysics · Physics 2013-11-12 Shinji Tsujikawa , Junko Ohashi , Sachiko Kuroyanagi , Antonio De Felice

We review experimental and theoretical developments in inflation and its application to structure formation, including the curvaton idea. We then discuss a particle physics model of supersymmetric hybrid inflation at the intermediate scale…

High Energy Physics - Phenomenology · Physics 2008-11-26 S. F. King

In the simplest scenario for inflation, i. e. in the single-field inflation, it is presented an inflaton field with properties equivalent to a generalized Chaplygin gas. Their study is performed using the Hamilton-Jacobi approach to…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Sergio del Campo

We study cosmological gravitational particle production (CGPP) in Higgs inflation, wherein the inflaton is a scalar field with quartic self-coupling $\lambda$ and a nonminimal coupling to gravity $\xi$, and which may, but need not be, the…

High Energy Physics - Phenomenology · Physics 2025-10-29 Tammi Chowdhury , Leah Jenks , Edward W. Kolb , Evan McDonough

An extension of the Standard Model with three right-handed neutrinos and a simple invisible axion model can account for all experimentally confirmed signals of new physics (neutrino oscillations, dark matter and baryon asymmetry) in…

High Energy Physics - Phenomenology · Physics 2019-02-06 Alberto Salvio

If a coupling between the inflaton and the Gauss-Bonnet term is introduced, many models of inflation that were ruled out by the most recent Planck data can be made viable again. The predictions for the scalar spectral index and…

General Relativity and Quantum Cosmology · Physics 2025-04-22 Kamil Mudrunka , Kazunori Nakayama

Cosmological models with inflation and those with bounce have their own strengths and weaknesses. Here we construct a model in which a phase of bounce is followed by a viable inflationary phase. This incorporates several advantages of both…

Cosmology and Nongalactic Astrophysics · Physics 2024-04-02 Manjeet Kaur , Debottam Nandi , Debajyoti Choudhury , T. R. Seshadri

In the framework of classical scale invariance, we consider quadratic gravity in the Palatini formalism and investigate the inflationary predictions of the theory. Our model corresponds to a two-field scalar-tensor theory, that involves the…

Cosmology and Nongalactic Astrophysics · Physics 2021-07-28 Ioannis D. Gialamas , Alexandros Karam , Thomas D. Pappas , Vassilis C. Spanos

If the inflaton is a pseudo-scalar axion, the axion shift symmetry can protect the flatness of its potential from too large radiative corrections. This possibility, known as natural inflation, requires an axion scale which is greater than…

High Energy Physics - Phenomenology · Physics 2009-11-10 Jihn E. Kim , Hans Peter Nilles , Marco Peloso

A family of de Sitter vacua introduced in hep-th/0203198 as plausible initial conditions for inflation, are discussed from the point of view of de Sitter holography. The vacua are argued to be physically acceptable and the inflationary…

High Energy Physics - Theory · Physics 2009-11-07 Ulf H. Danielsson

A correction to the Quartic Hilltop inflationary model is proposed to account for stabilising terms in the potential. We derive analytical predictions for the spectral index $n_s$ and tensor-scalar ratio $r$ which lie within the Planck 2018…

General Relativity and Quantum Cosmology · Physics 2022-01-05 Josh Hoffmann , David Sloan

We argue that all the necessary ingredients for successful inflation are present in the flat directions of the Minimally Supersymmetric Standard Model. We show that out of many gauge invariant combinations of squarks, sleptons and Higgses,…

High Energy Physics - Phenomenology · Physics 2008-11-26 Rouzbeh Allahverdi , Juan Garcia-Bellido , Kari Enqvist , Anupam Mazumdar

We study the scenario of inflection point inflation where a flat direction of the minimal supersymmetric standard model (MSSM) is identified with the inflaton. Specifically, we consider in full generality the cases where a MSSM flat…

High Energy Physics - Phenomenology · Physics 2024-08-27 Naoyuki Haba , Yasuhiro Shimizu , Yoshihiro Tanabe , Toshifumi Yamada

For hybrid inflationary potentials, we derive the tunneling rate from field configurations along the flat direction towards the waterfall regime. This process competes with the classically rolling evolution of the scalar fields and needs to…

High Energy Physics - Phenomenology · Physics 2010-10-27 Bjorn Garbrecht , Thomas Konstandin

We study a generalized version of hilltop inflation where the standard hilltop potential has been raised to a power and we allow fractional numbers for both the original hilltop power ($m$) and the overall exponent ($n$). In the parameter…

Cosmology and Nongalactic Astrophysics · Physics 2023-10-12 Helena Grete Lillepalu , Antonio Racioppi

We consider hybrid inflation for small couplings of the inflaton to matter such that the critical value of the inflaton field exceeds the Planck mass. It has recently been shown that inflation then continues at subcritical inflaton field…

High Energy Physics - Phenomenology · Physics 2015-04-16 Wilfried Buchmuller , Koji Ishiwata

We study inflection point inflation using Singularity Theory, which relates degenerate critical points of functions to their local behavior. This approach illuminates universal features of small-field models and gives analytic control over…

High Energy Physics - Theory · Physics 2011-09-28 Sean Downes , Bhaskar Dutta , Kuver Sinha