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Related papers: K-inflationary Power Spectra in the Uniform Approx…

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We consider an action for gravity that, in addition to the Einstein-Hilbert term, contains a function of the Ricci scalar and the Gauss-Bonnet invariant. The specific form of the function considered is motivated by holographic cosmology. At…

General Relativity and Quantum Cosmology · Physics 2022-01-27 Nicolas R. Bertini , Neven Bilic , Davi C. Rodrigues

We develop a frame-covariant formulation of inflation in the slow-roll approximation by generalizing the inflationary attractor solution for scalar-curvature theories. Our formulation gives rise to new generalized forms for the potential…

High Energy Physics - Phenomenology · Physics 2016-06-22 Daniel Burns , Sotirios Karamitsos , Apostolos Pilaftsis

In the present paper, we perform a sub-Planckian quantum mode analysis of linear cosmological perturbation in the inflaton field over a classical quasi de-Siter metric background by dynamical horizon exit (DHE) method. In this way, we probe…

General Relativity and Quantum Cosmology · Physics 2023-05-05 Arunoday Sarkar , Buddhadeb Ghosh

We construct ensembles of random scalar potentials for $N_f$ interacting scalar fields using non-equilibrium random matrix theory, and use these to study the generation of observables during small-field inflation. For $N_f={\cal O}({\rm…

Cosmology and Nongalactic Astrophysics · Physics 2016-10-05 Mafalda Dias , Jonathan Frazer , M. C. David Marsh

We derive the primordial power spectrum of density fluctuations in the framework of quantum cosmology. For this purpose we perform a Born-Oppenheimer approximation to the Wheeler-DeWitt equation for an inflationary universe with a scalar…

General Relativity and Quantum Cosmology · Physics 2012-01-17 Claus Kiefer , Manuel Kraemer

Prior to recombination, Silk damping causes the dissipation of energy from acoustic waves into the monopole of the Cosmic Microwave Background (CMB), resulting in spectral distortions. These can be used to probe the primordial scalar power…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 Sebastien Clesse , Björn Garbrecht , Yi Zhu

The bispectrum of single-field inflationary trajectories in which the speed of sound of the inflationary trajectories $c_s$ is constant but not equal to the speed of light $c=1$ is explored. The trajectories are generated as random…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-30 Jonathan S. Horner , Carlo R. Contaldi

We derive a general expression for the power spectra of scalar and tensor fluctuations generated during inflation given an arbitrary choice of boundary condition for the mode function at a short distance. We assume that the boundary…

High Energy Physics - Theory · Physics 2008-11-26 Richard Easther , Brian R. Greene , William H. Kinney , Gary Shiu

We describe models of single-field inflation with small and sharp step features in the potential (and sound speed) of the inflaton field, in the context of the Effective Field Theory of Inflation. This approach allows us to study the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Nicola Bartolo , Dario Cannone , Sabino Matarrese

The next decade will feature an abundance of novel cosmological data, while many fundamental questions about inflation remain. Given this, there is ample need for maximally efficient calculations, especially in non-standard scenarios for…

General Relativity and Quantum Cosmology · Physics 2023-05-10 Panagiotis Christeas , Logan Thomas

Standard inflationary models yield a characteristic signature of a primordial power spectrum with a red tensor and scalar tilt. Nevertheless, Cannone et al recently suggested that, by breaking the assumption of spatial diffeomorphism…

Cosmology and Nongalactic Astrophysics · Physics 2018-11-20 Leila Graef , Robert Brandenberger

We propose a warm inflationary model in the context of relativistic D-brane inflation in a warped throat, which has Dirac-Born-Infeld (DBI) kinetic term and is coupled to radiation through a dissipation term. The perturbation freezes at the…

High Energy Physics - Theory · Physics 2011-05-23 Yi-Fu Cai , James B. Dent , Damien A. Easson

The ultra-slow-roll (USR) inflationary models predict large-amplitude scalar perturbations at small scales which can lead to the primordial black hole production and scalar-induced gravitational waves. In general scalar perturbations in the…

Cosmology and Nongalactic Astrophysics · Physics 2020-04-29 Jing Liu , Zong-Kuan Guo , Rong-Gen Cai

We obtain the effective inflaton potential during slow roll inflation by including the one loop quantum corrections to the energy momentum tensor from scalar curvature and tensor perturbations as well as quantum fluctuations from light…

Astrophysics · Physics 2009-11-13 D. Boyanovsky , H. J. de Vega , N. G. Sanchez

We compute the universal generic corrections to the inflationary power spectrum due to unknown high-energy physics. We arrive at this result via a careful integrating out of massive fields in the "in-in" formalism yielding a consistent and…

High Energy Physics - Theory · Physics 2013-05-30 Mark G. Jackson , Koenraad Schalm

The observational constraints on the primordial power spectrum have tightened considerably with the release of the first year analysis of the WMAP observations, especially when combined with the results from other CMB experiments and galaxy…

High Energy Physics - Phenomenology · Physics 2009-11-10 Dominik J. Schwarz , Cesar A. Terrero-Escalante

For the inflaton perturbations it is shown that the evolution of the difference between the spectral indices can be translated into information on the scale dependence of the tensor to scalar amplitudes ratio, $r$, and how the scalar field…

Astrophysics · Physics 2009-11-07 C. A. Terrero-Escalante

Inflation produces nearly Harrison-Zel'dovich scalar and tensor perturbation spectra which lead to anisotropy in the cosmic microwave background (CMB). The amplitudes and shapes of these spectra can be parametrized by $Q_S^2$, $r\equiv…

Astrophysics · Physics 2009-10-28 Lloyd Knox

We consider slow-roll inflation for a single scalar field with an arbitrary potential and an arbitrary nonminimal coupling to the Gauss-Bonnet term. By introducing a combined hierarchy of Hubble and Gauss-Bonnet flow functions, we…

High Energy Physics - Theory · Physics 2014-11-20 Zong-Kuan Guo , Dominik J. Schwarz

Until recently our knowledge of the primordial curvature perturbation was relatively modest. Ever since COBE delivered its map of data we know the scalar spectrum of primordial perturbations is approximately flat, with the power being only…

Cosmology and Nongalactic Astrophysics · Physics 2013-09-24 Raquel H. Ribeiro
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