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Related papers: Initial conditions in hybrid inflation: exploratio…

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A scenario with two subsequent periods of inflationary expansion in the very early universe is examined. The model is based on a potential motivated by symmetries being found in field theory at high energy. For various parameter sets of the…

Cosmology and Nongalactic Astrophysics · Physics 2016-01-13 Simon Schettler , Jurgen Schaffner-Bielich

The early Universe inflation is well known as a promising theory to explain the origin of large scale structure of Universe and to solve the early universe pressing problems. For a resonable inflation model, the potential during inflation…

High Energy Physics - Phenomenology · Physics 2007-05-23 Xin He Meng

We analyze the onset of inflation for a simple single-field model when the system begins with significant inhomogeneities on length-scales shorter than the initial Hubble radius. We incorporate certain nonlinear interactions among the…

Cosmology and Nongalactic Astrophysics · Physics 2019-09-17 Jolyon K. Bloomfield , Patrick Fitzpatrick , Kiriakos Hilbert , David I. Kaiser

Many different models of inflation give rise to the same effective field theory of the inflaton. While effective field theories in flat space provide little information about UV physics, we propose that in inflationary backgrounds a large…

High Energy Physics - Theory · Physics 2012-01-04 Ross O'Connell , R. Holman

Computing the marginal likelihood or evidence is one of the core challenges in Bayesian analysis. While there are many established methods for estimating this quantity, they predominantly rely on using a large number of posterior samples…

Computation · Statistics 2021-02-26 Eric Chuu , Debdeep Pati , Anirban Bhattacharya

We reconsider the original model of quadratic hybrid inflation in light of the WMAP three-year results and study the possibility of obtaining a spectral index of primordial density perturbations, $n_s$, smaller than one from this model. The…

Astrophysics · Physics 2008-11-26 Antonio Cardoso

Inflation is now an accepted paradigm in standard cosmology, with its predictions consistent with observations of the cosmic microwave background. It lacks, however, a firm physical theory, with many possible theoretical origins beyond the…

Astrophysics · Physics 2009-01-16 Nishant Agarwal , Rachel Bean

Multifield models of inflation with nonminimal couplings are in excellent agreement with the recent results from {\it Planck}. Across a broad range of couplings and initial conditions, such models evolve along an effectively single-field…

Cosmology and Nongalactic Astrophysics · Physics 2014-01-08 David I. Kaiser , Evangelos I. Sfakianakis

Supersymmetric hybrid inflation is an exquisite framework to connect inflationary cosmology to particle physics at the scale of grand unification. Ending in a phase transition associated with spontaneous symmetry breaking, it can naturally…

High Energy Physics - Phenomenology · Physics 2014-07-31 Wilfried Buchmuller , Valerie Domcke , Kohei Kamada , Kai Schmitz

We introduce a numerical method specifically designed for investigating generic multifield models of inflation where a number of scalar fields $\phi^K$ are minimally coupled to gravity and live in a field space with a non-trivial metric…

Cosmology and Nongalactic Astrophysics · Physics 2023-12-14 William Giarè , Mariaveronica De Angelis , Carsten van de Bruck , Eleonora Di Valentino

We report first study of complex field inflation. Although understood as a specific two-field inflation, a complex field inflation is able to make more robust model predictions on primordial curvature perturbation. Explicitly we discuss the…

Cosmology and Nongalactic Astrophysics · Physics 2022-02-22 Ruopeng Zhang , Sibo Zheng

I give a brief review of the status of research on the nature of initial conditions required to obtain a period of cosmological inflation. It is shown that there is good evidence that in the case of large field models, the inflationary…

High Energy Physics - Theory · Physics 2017-02-08 Robert Brandenberger

We investigate the initial conditions of inflation in a Bianchi~I universe that is homogeneous but not isotropic. We use the Eisenhart lift to describe such a theory geometrically as geodesics on a field space manifold. We construct the…

General Relativity and Quantum Cosmology · Physics 2020-03-18 Kieran Finn

We consider the robustness of small-field inflation in the presence of scalar field inhomogeneities. Previous numerical work has shown that if the scalar potential is flat only over a narrow interval, such as in commonly considered…

General Relativity and Quantum Cosmology · Physics 2018-09-05 M. C. David Marsh , John D. Barrow , Chandrima Ganguly

We perform a numerical investigation of the fields evolution in the supersymmetric inflationary model based on radiative corrections. Supergravity corrections are also included. We find that, out of all the examined initial data, only about…

High Energy Physics - Phenomenology · Physics 2008-11-26 G. Lazarides , N. D. Vlachos

We consider a variant of Hybrid Inflation, where inflation is driven by two interacting scalar fields, one of which has a `Mexican hat' potential and the other a quartic potential. Given the appropriate initial conditions one of the fields…

Astrophysics · Physics 2016-08-24 David Roberts , Andrew R Liddle , David H Lyth

Recently, there are several reports that the cosmic magnetic fields on Mpc scale in void region is larger than $\sim 10^{-15}$G with an uncertainty of a few orders from the current blazar observations. On the other hand, in inflationary…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 Tomohiro Fujita , Shuichiro Yokoyama

The original model of axion natural inflation produces a tensor-to-scalar ratio above the experimental limit. Aligned axion inflation admits inflationary trajectories that originate near a saddle point of the two-field potential, and…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-20 Federico Greco , Marco Peloso

We revisit the status of hybrid inflation in the light of Planck and recent BICEP2 results, taking care of possible transient violations of the slow-roll conditions as the field passes from the large field to the vacuum dominated phase. The…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-05 Sebastien Clesse , Jeremy Rekier

We suggest a new type of hill-top inflation originating from the initial conditions in the form of the microcanonical density matrix for the cosmological model with a large number of quantum fields conformally coupled to gravity. Initial…

High Energy Physics - Theory · Physics 2016-01-27 A. O. Barvinsky , A. Yu. Kamenshchik , D. V. Nesterov