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Related papers: Conformal inflation in the metric-affine geometry

200 papers

Recently, several broad classes of inflationary models have been discovered whose cosmological predictions are stable with respect to significant modifications of the inflaton potential. Some classes of models are based on a non-minimal…

High Energy Physics - Theory · Physics 2015-04-16 Mario Galante , Renata Kallosh , Andrei Linde , Diederik Roest

We define a general class of superconformal inflationary attractor models studied in our previous papers [1,2], which include, among others, inflationary models of 'induced gravity' which were argued to retain perturbative unitarity up to…

High Energy Physics - Theory · Physics 2015-06-18 Renata Kallosh

Infrared growth of geometrical fluctuations in inflationary spacetimes is investigated. The problem of gauge-invariant characterization of growth of perturbations, which is of interest also in other spacetimes such as black holes, is…

High Energy Physics - Theory · Physics 2013-05-30 Steven B. Giddings , Martin S. Sloth

We elaborate on a minimal inflation scenario based entirely on the general properties of supersymmetry breaking in supergravity models. We identify the inflaton as the scalar component of the Goldstino superfield. We write plausible…

High Energy Physics - Theory · Physics 2011-10-19 Luis Alvarez-Gaume , Cesar Gomez , Raul Jimenez

During inflation, spacetime is approximately described by de Sitter space which is conformally invariant with the symmetry group SO(1,4). This symmetry can significantly constrain the quantum perturbations which arise in the inflationary…

High Energy Physics - Theory · Physics 2013-10-30 Ishan Mata , Suvrat Raju , Sandip Trivedi

We study the generation of local non-Gaussianity in models of canonical single field inflation when their backgrounds are either attractor or non-attractor. We show that the invariance of inflation under space-time diffeomorphisms can be…

High Energy Physics - Theory · Physics 2023-04-13 Rafael Bravo , Gonzalo A. Palma

We introduce a new approach for computing curvature of sub-Riemannian manifolds. Curvature is here meant as symplectic invariants of Jacobi curves of geodesics, as introduced by Zelenko and Li. We describe how they can be expressed using a…

Differential Geometry · Mathematics 2020-03-24 Erlend Grong

We consider an additional fine-tuning problem which afflicts scalar-driven models of inflation. The problem is that successful reheating requires the inflaton be coupled to ordinary matter, and quantum fluctuations of this matter induces…

General Relativity and Quantum Cosmology · Physics 2019-05-22 Z. H. Liao , S. P. Miao , R. P. Woodard

We review and relate two recent complementary constructions of linear local gauge-invariant observables for cosmological perturbations in generic spatially flat single-field inflationary cosmologies. After briefly discussing their physical…

General Relativity and Quantum Cosmology · Physics 2019-09-20 Markus B. Fröb , Thomas-Paul Hack , Igor Khavkine

Extensions of the Standard Model and general relativity featuring a UV fixed point can leave observable implications at accessible energies. Although mass parameters such as the Planck scale can appear through dimensional transmutation, all…

High Energy Physics - Phenomenology · Physics 2019-09-13 Alberto Salvio

We perform an analysis of models of chaotic inflation where the inflaton field $\phi$ is coupled non-minimally to gravity via $\xi \phi^n g^{\mu\nu}R_{\mu\nu}(\Gamma), n>0$. We focus on the Palatini theory of gravity, i.e. the case where…

General Relativity and Quantum Cosmology · Physics 2018-04-20 Laur Järv , Antonio Racioppi , Tommi Tenkanen

In this paper we study non-abelian gauge field inflation (gauge-flation) model in the context of intermediate and logamediate scenario. Important parameters of this model are presented for these two cases. Numerical study shows that the…

General Relativity and Quantum Cosmology · Physics 2014-01-08 M. R. Setare , V. Kamali

Given a flat metric one may generate a local Hamiltonian structure via the fundamental result of Dubrovin and Novikov. More generally, a flat pencil of metrics will generate a local bi-Hamiltonian structure, and with additional…

Differential Geometry · Mathematics 2020-12-16 Liana David , Ian A. B. Strachan

Pseudo-Riemannian metrics with Levi-Civita connection in the projective class of a given torsion free affine connection can be obtained from (and are equivalent to) the maximal rank solutions of a certain overdetermined projectively…

Differential Geometry · Mathematics 2018-03-05 Keegan J. Flood , A. Rod Gover

It has been previously shown that the linear inflation appears naturally as a solution of Coleman-Weinberg inflation, provided that the inflaton has a non-minimal coupling to gravity and the Planck scale is dynamically generated. We revisit…

Cosmology and Nongalactic Astrophysics · Physics 2018-01-09 Antonio Racioppi

The nonlinear affine Goldstone model of the emergent gravity, built on the nonlinearly realized/hidden affine symmetry, is concisely revisited. Beyond General Relativity, the explicit violation of general invariance/relativity, under…

General Relativity and Quantum Cosmology · Physics 2015-06-19 Yu. F. Pirogov

We apply the Effective Field Theory of Inflation to study the case where the continuous shift symmetry of the Goldstone boson \pi is softly broken to a discrete subgroup. This case includes and generalizes recently proposed String Theory…

High Energy Physics - Theory · Physics 2015-06-03 Siavosh R. Behbahani , Anatoly Dymarsky , Mehrdad Mirbabayi , Leonardo Senatore

The intrinsic transverse size of nucleons, parameterized by a Gaussian width $w$, is a critical yet uncertain input in the initial-state modeling of relativistic heavy-ion collisions. Using a finite $w$ in standard initial geometry models…

Nuclear Theory · Physics 2026-02-27 Jian-fei Wang , Hao-jie Xu

This article presents an exhaustive classification of metric-affine theories according to their scale symmetries. First it is clarified that there are three relevant definitions of a scale transformation. These correspond to a projective…

General Relativity and Quantum Cosmology · Physics 2021-04-02 Damianos Iosifidis , Tomi Koivisto

This is the second in a series of papers where we prove a conjecture of Deser and Schwimmer regarding the algebraic structure of ``global conformal invariants''; these are defined to be conformally invariant integrals of geometric scalars.…

Differential Geometry · Mathematics 2009-12-21 Spyros Alexakis