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Related papers: Noncommutativity, Saez-Ballester theory and kineti…

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Noncommutative geometry can provide effective description of physics at very short distances taking into account generic effects of quantum gravity. Inflation amplifies tiny quantum fluctuations in the early universe to macroscopic scales…

Cosmology and Nongalactic Astrophysics · Physics 2011-03-18 Tomi S. Koivisto , David F. Mota

In this paper, we would like to examine whether the S\'aez-Ballester theory admits stable and attractive Bianchi type I inflationary solutions in the presence of a non-minimal coupling between scalar and vector fields such as…

General Relativity and Quantum Cosmology · Physics 2025-07-04 Tuan Q. Do , Phung V. Dong , Duy H. Nguyen , J. K. Singh

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 investigate how the uncertainty of noncommutative spacetime affects on inflation. For this purpose, the noncommutative parameter $\mu_0$ is taken to be a zeroth order slow-roll parameter. We calculate the noncommutative power spectrum up…

High Energy Physics - Theory · Physics 2009-11-10 Hungsoo Kim , Gil Sang Lee , Hyung Won Lee , Yun Soo Myung

We study the production of observable primordial local non-Gaussianity in two opposite regimes of canonical single field inflation: attractor (standard single field slow-roll inflation) and non attractor (ultra slow-roll inflation). In the…

Cosmology and Nongalactic Astrophysics · Physics 2018-05-15 Rafael Bravo , Sander Mooij , Gonzalo A. Palma , Bastián Pradenas

Non-commutative inflation is a modification of standard general relativity inflation which takes into account some effects of the space-time uncertainty principle motivated by ideas from string theory. The corrections to the primordial…

Astrophysics · Physics 2009-03-31 Shinji Tsujikawa , Roy Maartens , Robert Brandenberger

In this paper we investigate to which extent noncommutativity, a intrinsically quantum property, may influence the Friedmann-Robertson-Walker cosmological dynamics at late times/large scales. To our purpose it will be enough to explore the…

General Relativity and Quantum Cosmology · Physics 2011-08-10 Octavio Obregon , Israel Quiros

In this work, we study inflation in a particular scalar-vector-tensor theory of gravitation without the $U(1)$ gauge symmetry. The model is constructed from the more general action introduced in Heisenberg et al. (Phys Rev D 98:024038,…

Cosmology and Nongalactic Astrophysics · Physics 2022-01-20 A. Oliveros , Cristhian J. Rodríguez

Very recent CMB data of WMAP offers an opportunity to test inflation models, in particular, the running of spectral index is quite new and can be used to rule out some models. We show that an noncommutative spacetime inflation model gives a…

High Energy Physics - Theory · Physics 2009-11-10 Qing Guo Huang , Miao Li

In this paper we develop the formalism for the stochastic approach to inflation at all order in slow-roll parameters. This is done by including the momentum and Hamiltonian constraints into the stochastic equations. We then specialise to…

General Relativity and Quantum Cosmology · Physics 2022-02-09 Diego Cruces , Cristiano Germani

For simple inflationary models, we provide a consistent and complete scheme by which the macro-physical details of early universe inflation may be determined explicitly from the underlying micro-physical theory. We examine inflationary…

High Energy Physics - Phenomenology · Physics 2007-05-23 D. Cormier

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

We study the stochastic formalism of inflation beyond the usual slow-roll approximation. We verify that the assumptions on which the stochastic formalism relies still hold even far from the slow-roll attractor. This includes demonstrating…

Cosmology and Nongalactic Astrophysics · Physics 2019-11-05 Chris Pattison , Vincent Vennin , Hooshyar Assadullahi , David Wands

We present a unified framework that simultaneously addresses the dynamics of early-time cosmic inflation and late-time cosmic acceleration within the context of a single scalar field non-minimally coupled to gravity. By employing an…

General Relativity and Quantum Cosmology · Physics 2025-10-27 Seong Chan Park

We consider a semi-classical approximation to the dynamics of a point particle in a noncommutative space. In this approximation, the noncommutativity of space coordinates is described by a Poisson bracket. For linear Poisson brackets, the…

High Energy Physics - Theory · Physics 2024-05-24 Vladislav Kupriyanov , Maxim Kurkov , Alexey Sharapov

In this study, we explore the dynamics of warm inflation within a non-minimally coupled Peccei-Quinn (PQ) framework and evaluate its compatibility with the de Sitter Swampland Conjecture. Our model incorporates a PQ scalar field that is…

General Relativity and Quantum Cosmology · Physics 2024-10-17 Jureeporn Yuennan , Phongpichit Channuie , Davood Momeni

Following an elegant approach that merge the effects of the stringy spacetime uncertainty relation into primordial perturbations suggested by Brandenberger and Ho, we show the mode equation up to the first order of non-commutative…

High Energy Physics - Theory · Physics 2009-11-10 Dao-jun Liu , Xin-zhou Li

In [arXiv:1102.1513] we introduced an inflationary scenario, Non-Abelian Gauge Field Inflation or gauge-flation for short, in which slow-roll inflation is driven by non-Abelian gauge field minimally coupled to gravity. We present a more…

High Energy Physics - Phenomenology · Physics 2015-03-18 A. Maleknejad , M. M. Sheikh-Jabbari

We study a single field inflationary model modified by a non-minimal coupling term between the Ricci scalar $R$ and the scalar field $\varphi$ in the context of constant-roll inflation. The first-order formalism is used to analyse the…

General Relativity and Quantum Cosmology · Physics 2021-08-11 Mehdi Shokri , Jafar Sadeghi , Mohammad Reza Setare , Salvatore Capozziello

We study the implications of a noncommutative geometry of the minisuperspace variables for the FRW universe with a conformally coupled scalar field. The investigation is carried out by means of a comparative study of the universe evolution…

High Energy Physics - Theory · Physics 2009-11-10 G. D. Barbosa