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We explore a model of inflation where the inflaton mass-squared is generated at a high scale by gravity-mediated soft supersymmetry breaking, and runs at lower scales to the small value required for slow-roll inflation. The running is…

High Energy Physics - Phenomenology · Physics 2009-10-31 Laura Covi , David H. Lyth , Leszek Roszkowski

CMB anisotropies are modified by the weak lensing effect of intervening large scale structures on the photon path from the last scattering surface to the observer. This has to be accounted for when observational data of sensitive…

Astrophysics · Physics 2010-10-27 Jonathan Rocher , Karim Benabed , Francois Bouchet

It is conjectured that inflation, taking account of quantum gravity, leads to a discrete spectrum of cosmological perturbations, instead of the continuous Gaussian spectrum predicted by standard field theory in an unquantized background.…

Astrophysics · Physics 2009-11-10 Craig J. Hogan

We study a warm inflationary model for different expansions assuming an anisotropic universe described by Bianchi I metric. The universe is filled with a scalar field or inflaton, radiation, and bulk viscous pressure. We carry out the…

General Relativity and Quantum Cosmology · Physics 2022-02-07 Mehdi Shokri , Jafar Sadeghi , Ramón Herrera , Saeed Noori Gashti

We develop the stochastic formalism for $\mathrm{U}(1)$ gauge fields that has the Chern-Simons coupling to a rolling pseudo-scalar field during inflation. The Langevin equations for the physical electromagnetic fields are derived and the…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-11 Tomohiro Fujita , Kyohei Mukaida , Yuichiro Tada

We propose a scenario where inflation is driven by non-minimally coupled massive vector fields. In an isotropic homogeneous universe these fields behave in presicely the same way as a massive minimally coupled scalar field. Therefore our…

Astrophysics · Physics 2009-03-20 Alexey Golovnev , Viatcheslav Mukhanov , Vitaly Vanchurin

Gauge-flation, non-Abelian gauge field inflation, which was introduced in arXiv:1102.1513 and analyzed more thoroughly in arXiv:1102.1932, is a model of inflation driven by non-Abelian gauge fields minimally coupled to Einstein gravity. In…

High Energy Physics - Theory · Physics 2015-06-04 M. M. Sheikh-Jabbari

We investigate the possibility of inflation with models of antisymmetric tensor field having minimal and nonminimal couplings to gravity. Although the minimal model does not support inflation, the nonminimal models, through the introduction…

General Relativity and Quantum Cosmology · Physics 2018-11-02 Sandeep Aashish , Abhilash Padhy , Sukanta Panda , Arun Rana

We study the observational implications of a class of inflationary models wherein the inflaton is coupled to the Einstein tensor through a generalized non-minimal derivative coupling (GNMDC). In particular, we explore whether these models…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-03 Yashi Tiwari , Nilanjandev Bhaumik , Rajeev Kumar Jain

We show that the difference between the theoretically expected and measured by WMAP amplitude of the quadrupole fluctuations of CMB can be related to the impact of the anisotropic curvature of the homogeneous universe dominated by the dark…

Astrophysics · Physics 2008-11-26 M. Demiański , A. G. Doroshkevich

Inflation may provide a suitable collider to probe physics at very high energies. In this paper we investigate the impact on the CMB bispectrum of higher spin fields which are long-lived on super-Hubble scales, e.g. partially massless…

Cosmology and Nongalactic Astrophysics · Physics 2018-08-30 Gabriele Franciolini , Alex Kehagias , Antonio Riotto , Maresuke Shiraishi

We consider a double-inflationary model with two massive scalar fields interacting only gravitationally in the context of a flat cold dark matter (CDM) Universe. The cosmic microwave background (CMB) temperature anisotropies produced in…

Astrophysics · Physics 2009-10-30 Julien Lesgourgues , David Polarski

The stochastic inflation program is a framework for understanding the dynamics of a quantum scalar field driving an inflationary phase. Though widely used and accepted, there have over recent years been serious criticisms of this theory. In…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Andrew Matacz

We propose a model for cosmic inflation which is based on an effective description of strongly interacting, nonsupersymmetric matter within the framework of dynamical abelian projection and centerization. The underlying gauge symmetry is…

High Energy Physics - Phenomenology · Physics 2007-05-23 Ralf Hofmann , Mathias Th. Keil

We present the effective field theory studies of primordial statistical anisotropies in models of anisotropic inflation. The general action in unitary gauge is presented to calculate the leading interactions between the gauge field…

Cosmology and Nongalactic Astrophysics · Physics 2020-05-26 Tahereh Rostami , Asieh Karami , Hassan Firouzjahi

As opposed to Wald's cosmic no-hair theorem in general relativity, it is shown that the Horndeski theory (and its generalization) admits anisotropic inflationary attractors if the Lagrangian depends cubically on the second derivatives of…

General Relativity and Quantum Cosmology · Physics 2018-08-01 Hiroaki W. H. Tahara , Sakine Nishi , Tsutomu Kobayashi , Jun'ichi Yokoyama

We propose a new mechanism to generate density perturbations in inflationary models. Spatial fluctuations in the decay rate of the inflaton field to ordinary matter lead to fluctuations in the reheating temperature. We argue that in most…

Astrophysics · Physics 2009-11-07 Gia Dvali , Andrei Gruzinov , Matias Zaldarriaga

This paper is aimed to study the compelling issue of cosmic inflation during rapid oscillations using the framework of non-minimal derivative coupling. To this end, an anisotropic and homogeneous Bianchi I background is considered. In this…

General Relativity and Quantum Cosmology · Physics 2018-11-29 Rabia Saleem

The simplicity of the CMB data, so well described by single-field inflation, raises the question whether there might be an equally simple multi-field realization consistent with the observations. We explore the idea that an approximate…

High Energy Physics - Theory · Physics 2019-07-04 Ana Achucarro , Yvette Welling

We consider the non-minimal model of gravity in $Y(R) F^2$-form. We investigate a particular case of the model, for which the higher order derivatives are eliminated but the scalar curvature $R$ is kept to be dynamical via the constraint…

General Relativity and Quantum Cosmology · Physics 2017-11-17 Muzaffer Adak , Ozgur Akarsu , Tekin Dereli , Ozcan Sert