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We discuss a new scenario for early cosmology, when inflationary de Sitter phase dynamically emergent. This genuine quantum effect occurs as a result of dynamics of the topologically nontrivial sectors in a (conjectured) strongly coupled…

High Energy Physics - Phenomenology · Physics 2014-08-13 Ariel R. Zhitnitsky

The scalar perturbations in inflationary models, based on a two-component diagonal non-linear sigma model, are considered. For inhomogeneities generated at an inflationary stage, the law of motion of the comoving curvature ${\cal R}$ is…

Astrophysics · Physics 2007-05-23 N. A. Koshelev

We consider inflation with a constant rate of rolling in which a complex scalar field plays the role of inflaton during the inflationary epoch. We implement the inflationary analysis for an accredited angular speed $\dot{\theta}$ which…

General Relativity and Quantum Cosmology · Physics 2024-05-16 Ramón Herrera , Mehdi Shokri , Jafar Sadeghi

We propose a cosmological framework in which neutrino masses evolve dynamically through coupling with a scalar field that simultaneously drives inflation. The neutrino mass is modeled as a power-law, exponential, or hybrid function of the…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-01 Hemanshi Bundeliya , Gaurav Bhandari , S. D. Pathak , V. K. Sharma

SU(2) gauge fields coupled to an axion field can acquire an isotropic background solution during inflation. We study homogeneous but anisotropic inflationary solutions in the presence of such (massless) gauge fields. A gauge field in the…

General Relativity and Quantum Cosmology · Physics 2021-09-28 Ira Wolfson , Azadeh Maleknejad , Tomoaki Murata , Eiichiro Komatsu , Tsutomu Kobayashi

We investigate the inflationary predictions of a simple Horndeski theory where the inflaton scalar field has a non-minimal derivative coupling (NMDC) to the Einstein tensor. The NMDC is very motivated for the construction of successful…

General Relativity and Quantum Cosmology · Physics 2017-02-22 Ioannis Dalianis , George Koutsoumbas , Konstantinos Ntrekis , Eleftherios Papantonopoulos

Slow-roll inflation can be studied as an effective field theory. The form of the inflaton potential consistent with the data is V(phi) = N M^4 w(phi/[sqrt{N} M_{Pl}]) where phi is the inflaton field, M is the inflation energy scale, and N ~…

Astrophysics · Physics 2007-05-23 D. Boyanovsky , H. J. de Vega , N. G. Sanchez

We study nonlinear cosmological perturbations and their possible non-Gaussian character in an extended non-minimal inflation where gravity is coupled non-minimally to both the scalar field and its derivatives. By expansion of the action up…

General Relativity and Quantum Cosmology · Physics 2019-10-09 Raheleh Shojaee , Kourosh Nozari , Farhad Darabi

We study the intermediate tachyon inflation in an anisotropic background. By using the Friedmann equations obtained in the anisotropic geometry, we obtain the slow-roll parameters in the tachyon model. The presence of the anisotropic…

Cosmology and Nongalactic Astrophysics · Physics 2024-02-05 Narges Rashidi

We study primordial anisotropies generated in the model of gauged hybrid inflation in which the complex waterfall field is charged under a $U(1)$ gauge field. Primordial anisotropies are generated either actively during inflation or from…

High Energy Physics - Theory · Physics 2015-06-17 Ali Akbar Abolhasani , Razieh Emami , Hassan Firouzjahi

We discuss the hybrid inflation model where the inflaton field is nonminimally coupled to gravity. In the Jordan frame, the potential contains $\phi^4$ term as well as terms in the original hybrid inflation model. In our model, inflation…

High Energy Physics - Theory · Physics 2011-02-22 Seoktae Koh , Masato Minamitsuji

During inflation, higher derivative terms in the gravitational action may play a significant role. Building on new stable formulations of four-derivative scalar-tensor theories, we study the impact of these corrections in the case where the…

General Relativity and Quantum Cosmology · Physics 2025-05-26 Sam E. Brady , Katy Clough , Pau Figueras , Áron D. Kovács

We investigate the cosmological inflation for the Einstein-Hilbert action plus the Higgs potential function and the Gauss-Bonnet term coupled with the Higgs scalar field through a dilaton-like coupling. Then, using the…

General Relativity and Quantum Cosmology · Physics 2026-05-29 Zahra Ahghari , Mehrdad Farhoudi

We consider initial conditions for inflation in non-minimal kinetic coupling theory. If inflation is driven solely by kinetic term with no potential, the resulting number of e-folds depends only upon initial velocity of the scalar field…

General Relativity and Quantum Cosmology · Physics 2021-09-29 N. Avdeev , A. Toporensky

We derive the power spectra of the scalar- and tensor-type structures generated in a chaotic-type inflation model based on non-minimally coupled scalar field with a self interaction. By comparing contributions of both-structures to the…

Astrophysics · Physics 2007-05-23 J. Hwang , H. Noh

We show how we can implement chaotic inflation in the context of supergravity by conveniently selecting the functional form of a strong enough non-minimal coupling between the inflaton and the Ricci scalar curvature. The procedure can be…

High Energy Physics - Phenomenology · Physics 2014-12-12 C. Pallis

We examine the inflationary modes in the cubic curvature theories in the context of asymptotically safe gravity. On the phase space of the Hubble parameter, there exists a critical point which corresponds to the slow-roll inflation in…

General Relativity and Quantum Cosmology · Physics 2012-08-09 Sungwook E. Hong , Young Jae Lee , Heeseung Zoe

Tensor non-Gaussianity represents an important future probe of the physics of inflation. Inspired by recent works, we elaborate further on the possibility of significant primordial tensor non-Gaussianities sourced by extra fields during…

Cosmology and Nongalactic Astrophysics · Physics 2019-02-20 Emanuela Dimastrogiovanni , Matteo Fasiello , Gianmassimo Tasinato , David Wands

In this paper, we would like to examine whether the S\'aez-Ballester theory admits stable and attractive Bianchi type I inflationary solutions in the presence of a non-minimal coupling between scalar and vector fields such as…

General Relativity and Quantum Cosmology · Physics 2025-07-04 Tuan Q. Do , Phung V. Dong , Duy H. Nguyen , J. K. Singh

Evidence for the presence of extra fields during inflation may be found in the anisotropies of the scalar and tensor spectra across a vast range of scales. Indeed, beyond the single-field slow-roll paradigm, a long tensor mode can modulate…

Cosmology and Nongalactic Astrophysics · Physics 2020-02-19 Emanuela Dimastrogiovanni , Matteo Fasiello , Gianmassimo Tasinato