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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 consider approaches to cosmological parameter estimation in the inflationary cosmology, focussing on the required accuracy of the initial power spectra. Parametrizing the spectra, for example by power-laws, is well suited to testing the…

Astrophysics · Physics 2009-11-07 Samuel M. Leach , Andrew R. Liddle , Jerome Martin , Dominik J. Schwarz

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

Inflationary cosmology proposes that the early Universe undergoes accelerated expansion, driven, in simple scenarios, by a single scalar field, or inflaton. The form of the inflaton potential determines the initial spectra of density…

Cosmology and Nongalactic Astrophysics · Physics 2022-09-21 Richard Easther , Benedict Bahr-Kalus , David Parkinson

A rigorous constraint analysis on cosmic inflation entails several probes which collectively survey an extensive range of energy scales. We complement the cosmic microwave background data with an updated compilation of the cosmic abundance…

Cosmology and Nongalactic Astrophysics · Physics 2019-04-23 Jurgen Mifsud , Carsten van de Bruck

We propose a mechanism for generating an inflationary phase in the early universe without resorting to any type of scalar field(s). Instead, this accelerated expansion is driven by a dynamical "cosmological constant" in the framework of…

General Relativity and Quantum Cosmology · Physics 2022-03-18 Gabriel Leon

The inflationary paradigm is an important cornerstone of the concordance cosmological model. However, standard inflation cannot fully address the transition from an early homogeneous and isotropic stage, to another one lacking such…

General Relativity and Quantum Cosmology · Physics 2015-12-08 Mauro Mariani , Gabriel R. Bengochea , Gabriel Leon

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

Using an approximate likelihood method adapted to band--power estimates, we analyze the ensemble of first generation cosmic microwave background anisotropy experiments to deduce constraints over a six--dimensional parameter space describing…

Astrophysics · Physics 2011-05-23 M. Le Dour , M. Douspis , J. G. Bartlett , A. Blanchard

An approach to construct cosmological inflation models on the basis of a certain dependence of the scalar field evolution on the e-folds number is considered. The reconstruction of the model background parameters according to the kind of…

General Relativity and Quantum Cosmology · Physics 2025-12-23 Igor V. Fomin , Vladimir L. Glushkov , Evgenii S. Dentsel , Gevorg D. Manucharyan , Vyacheslav A. Sizov

In this paper we use two methods to constrain the the canonical single-field slow-roll inflation model. The first method exploits the analytic slow-roll-parameter dependence of primordial perturbations, and the second consists of a…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-17 Jun Li , Guang-Hai Guo

We study the most general cosmological model with real scalar field which is minimally coupled to gravity. Our calculations are based on Friedmann-Lemaitre-Robertson-Walker (FLRW) background metric. Field equations consist of three…

General Relativity and Quantum Cosmology · Physics 2023-03-22 Medine Ildes , Metin Arik

We investigate constraints on power spectra of the primordial curvature and tensor perturbations with priors based on single-field slow-roll inflation models. We stochastically draw the Hubble slow-roll parameters and generate the…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Masahiro Kawasaki , Toyokazu Sekiguchi

Inflationary cosmology predicts that the particle horizon should be generically much bigger than the present-day Hubble radius, $1/H_0$. This implies a special regime of super-Hubble scale energy density fluctuations imprinted on the cosmic…

Astrophysics · Physics 2009-10-30 Arjun Berera , Li-Zhi Fang , Gary Hinshaw

This paper investigates a scale-invariant inflationary model characterized by a scalar field non-minimally coupled to gravity and a curvature term quadratic in the Ricci scalar. The model's dynamic is analyzed using a full numerical…

High Energy Physics - Theory · Physics 2024-10-10 Mariaveronica De Angelis , Chiara Cecchini , Massimiliano Rinaldi

We propose a new four-parameter entropy function that generalizes the Tsallis, R\'{e}nyi, Barrow, Sharma-Mittal, Kaniadakis and Loop Quantum Gravity entropies for suitable limits of the parameters. Consequently, we address the early and…

General Relativity and Quantum Cosmology · Physics 2022-06-15 Shin'ichi Nojiri , Sergei D. Odintsov , Tanmoy Paul

The capability of Cosmic Inflation to explain the latest Cosmic Microwave Background and Baryonic Acoustic Oscillation data is assessed by performing Bayesian model comparison within the landscape of nearly three-hundred models of…

Cosmology and Nongalactic Astrophysics · Physics 2024-08-27 Jerome Martin , Christophe Ringeval , Vincent Vennin

A Friedman cosmology is investigated based on scalar-tensor gravitation with general metric coupling and scalar potential functions. We show that for a broad class of such functions, the scalar field can be dynamically trapped using a…

General Relativity and Quantum Cosmology · Physics 2016-10-05 C. H. -T. Wang , J. A. Reid , A. St J. Murphy , D. Rodrigues , M. Al Alawi , R. Bingham , J. T. Mendonca , T. B. Davies

We calculate power spectra of cosmological perturbations at high accuracy for two classes of inflation models. We classify the models according to the behaviour of the Hubble distance during inflation. Our approximation works if the Hubble…

Astrophysics · Physics 2009-11-06 Dominik J. Schwarz , Cesar A. Terrero-Escalante , Alberto A. Garcia

Single-field models of $\alpha$-attractor quintessential inflation provide a unified picture of the two periods of early- and late-time cosmic acceleration, where both inflation and dark energy are described by a single scalar degree of…

Cosmology and Nongalactic Astrophysics · Physics 2021-04-05 Yashar Akrami , Santiago Casas , Senwen Deng , Valeri Vardanyan