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Related papers: Hamilton-Jacobi formalism for k-inflation

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In this paper we introduce the "warm vector inflation" scenario. In warm inflation scenario radiation is produced during the inflation epoch and reheating is avoided. Slow-roll and perturbation parameters of this model are presented. We…

General Relativity and Quantum Cosmology · Physics 2015-06-17 M. R. Setare , V. Kamali

We present two families of multi-field potentials that support inflation while satisfying the refined de Sitter and the distance swampland conjectures. Both families feature Planck-compatible phenomenology. The first is a helix-type…

High Energy Physics - Theory · Physics 2020-04-29 Vikas Aragam , Sonia Paban , Robert Rosati

By demanding the validity of an effective field theory description during inflation, in this note we derive some peculiar inequalities among the three interesting stringy and cosmological parameters, namely the tensor-to-scalar ratio ($r$),…

High Energy Physics - Theory · Physics 2016-07-04 Anupam Mazumdar , Pramod Shukla

In the absence of CMB precision measurements, a Taylor expansion has often been invoked to parametrize the Hubble flow function during inflation. The standard "horizon flow" procedure implicitly relies on this assumption. However, the…

Cosmology and Nongalactic Astrophysics · Physics 2015-11-25 Dries Coone , Diederik Roest , Vincent Vennin

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 explore the possibility of describing our universe with a singularity--free, closed, spatially homogeneous and isotropic cosmological model, using only general relativity and a suitable equation of state which produces an inflationary…

Astrophysics · Physics 2010-11-01 S. S. Bayin , F. I. Cooperstock , V. Faraoni

We use the 3+1 formalism of numerical relativity to investigate the robustness of Starobinsky and Higgs inflation to inhomogeneous initial conditions, in the form of either field gradient or kinetic energy density. Sub-Hubble and…

Cosmology and Nongalactic Astrophysics · Physics 2021-04-14 Cristian Joana , Sebastien Clesse

In 1998 Carlip and Solodukhin independently conjectured the equality between fluctuations in the modular Hamiltonian of black holes and its expectation value. Banks and Zurek's 2021 work generalized this observation to any causal diamonds.…

High Energy Physics - Theory · Physics 2025-09-03 Sidan A , Tom Banks

Next-to-leading order expressions related to Stewart-Lyth inverse problem are used to determine the inflationary models with a tensorial power spectrum described by a scale-invariant spectral index. Beyond power-law inflation, solutions are…

Astrophysics · Physics 2016-08-16 César A. Terrero-Escalante , Eloy Ayón-Beato , Alberto A. García

We investigate the observational constraints on three typical brane inflation models by considering the latest local measurement of the Hubble constant in the global fit. We also employ other observational data, including the Planck 2015…

Cosmology and Nongalactic Astrophysics · Physics 2018-11-30 Rui-Yun Guo , Lei Zhang , Jing-Fei Zhang , Xin Zhang

From the damping of the Cosmic Microwave Background Radiation (CMB) anisotropy power spectrum at large scale and the recent accelerating expansion of the Universe, we find that, there may be a largest scale which we can detect in the…

Astrophysics · Physics 2016-08-30 Wen Zhao , Yang Zhang

We propose a general inverse formula for extracting inflationary parameters from the observed power spectrum of cosmological perturbations. Under the general slow-roll scheme, which helps to probe the properties of inflation in a model…

Astrophysics · Physics 2009-11-10 Minu Joy , Ewan D. Stewart , Jinn-Ouk Gong , Hyun-Chul Lee

We study the complete evolution of a flat and homogeneous universe dominated by tachyonic matter. We demonstrate the attractor behaviour of the tachyonic inflation using the Hamilton-Jacobi formalism. We else obtain analytical…

High Energy Physics - Phenomenology · Physics 2007-05-23 Zong-Kuan Guo , Yun-Song Piao , Rong-Gen Cai , Yuan-Zhong Zhang

We investigate a standard minimally-coupled scalar-field inflationary scenario, which is based on a new potential, with suitably generalized plateau features, that leads to extra small tensor-to-scalar ratios. In particular, we consider a…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-13 Gerasimos Kouniatalis , Emmanuel N. Saridakis

A recent paper argued that it is not possible to infer the energy scale of inflation from the amplitude of tensor fluctuations in the Cosmic Microwave Background, because the usual connection is substantially altered if there are a large…

High Energy Physics - Theory · Physics 2016-01-20 Matthew Kleban , Mehrdad Mirbabayi , Massimo Porrati

The evolution of inflationary fluctuations can be recast as an inverse scattering problem. In this context, we employ the Gel'fand-Levitan method from inverse-scattering theory to reconstruct the evolution of both the inflaton field…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-15 Jorge Mastache , Fernando Zago , Arthur Kosowsky

We consider Higgs inflation with an $\alpha R^2$ term. It adds a new scalar degree of freedom, which leads to a two-field model of inflation. We do a complete slow-roll analysis of the three-dimensional parameter space of the $R^2$…

Cosmology and Nongalactic Astrophysics · Physics 2020-01-22 Vera-Maria Enckell , Kari Enqvist , Syksy Rasanen , Lumi-Pyry Wahlman

In this work, we present two classes of inflationary models in the framework of type IIB string theory. The inflatons correspond to blow-up K\"ahler modulus arising from compactifying type IIB string theory on a Calabi-Yau. Using…

High Energy Physics - Theory · Physics 2025-07-08 Mishaal Hai , Ahmed Rakin Kamal , Noshin Ferdous Shamma , Md Shaikot Jahan Shuvo

We consider inflation using a class of non-canonical Lagrangians for which the modification to the kinetic term depends on the field, but not its derivatives. We generalize the standard Hubble slow roll expansion to the non-canonical case…

Astrophysics · Physics 2010-10-27 Gabriela Barenboim , William H. Kinney

We propose a single field inflationary model by generalizing the inverse power law potential from the intermediate model. We study the implication of our model on the primordial anisotropy of cosmological microwave background radiation.…

High Energy Physics - Theory · Physics 2015-06-17 Zhun Lu
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