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Related papers: Inflation after Curvature Bounce

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We propose a novel scenario to explain the small cosmological constant (CC) by a finely tuned inflaton potential. The tuned shape is stable under radiative corrections, and our setup is technically natural. The peculiar po- tential…

High Energy Physics - Phenomenology · Physics 2022-10-05 Wen Yin

We study a nonsingular bounce inflation model, which can drive the early universe from a contracting phase, bounce into an ordinary inflationary phase, followed by the reheating process. Besides the bounce that avoided the Big-Bang…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Taotao Qiu , Yu-Tong Wang

A bouncing cosmology with an initial matter-dominated phase of contraction during which scales which are currently probed with cosmological observations exit the Hubble radius provides a mechanism alternative to inflation for producing a…

Cosmology and Nongalactic Astrophysics · Physics 2012-06-20 Robert H. Brandenberger

Inflationary homogeneous isotropic cosmological models filled by scalar fields and ultrarelativistic matter are examined in the framework of gauge theories of gravitation. By using quadratic scalar field potential numerical analysis of…

General Relativity and Quantum Cosmology · Physics 2007-05-23 A. V. Minkevich , A. S. Garkun

We investigate the cosmic inflation within a class of the scalar-tensor model with the scalar-dependent non-minimal kinetic couplings. The inflationary dynamical potential will be applied. Using the slow-roll approximation, we compute…

General Relativity and Quantum Cosmology · Physics 2025-12-01 Feyzollah Younesizadeh , Davoud Kamani

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

In this paper we study possible observational consequences of the bouncing cosmology. We consider a model where a phase of inflation is preceded by a cosmic bounce. While we consider in this paper only that the bounce is due to loop quantum…

General Relativity and Quantum Cosmology · Physics 2014-11-21 Jakub Mielczarek , Michal Kamionka , Aleksandra Kurek , Marek Szydlowski

Current observational data is consistent with the universe being slightly closed. We investigate families of singular and non-singular closed instantons that could describe the beginning of a closed inflationary universe. We calculate the…

Astrophysics · Physics 2009-11-07 Steven Gratton , Antony Lewis , Neil Turok

Modeling of matter bounce in $f(R,T)$ gravity has been presented with no violation of the null energy condition. Only a closed universe with negative pressure is allowed in good agreement with some recent observations which favor a universe…

General Relativity and Quantum Cosmology · Physics 2022-06-22 Vinod Kumar Bhardwaj , Anirudh Pradhan , Nasr Ahmed , A. A. Shaker

A viable model for inflation driven by a torsion function in a Friedmann background is presented. The scalar spectral index in the interval $0.92\lesssim n_{s}\lesssim 0.97$ is obtained in order to satisfy the initial conditions for…

General Relativity and Quantum Cosmology · Physics 2022-09-22 T. M. Guimarães , R. de C. Lima , S. H. Pereira

It is very difficult to obtain a realistic model of a closed inflationary universe. Even if one fine-tunes the total number of e-folds to be sufficiently small, the resulting universe typically has large density perturbations on the scale…

Astrophysics · Physics 2009-09-29 Andrei Linde

Using computer simulations we study the geometry of a typical quantum universe, i.e. the geometry one might expect before a possible period of inflation. We display it using coordinates defined by means of four classical scalar fields…

General Relativity and Quantum Cosmology · Physics 2021-09-01 J. Ambjorn , Z. Drogosz , J. Gizbert-Studnicki , A. Görlich , J. Jurkiewicz , D. Németh

Nonlinear electrodynamics with two dimensional parameters is studied. The range of electromagnetic fields when principles of causality, unitarity and the classical stability hold, are obtained. A singularity of the electric field at the…

General Relativity and Quantum Cosmology · Physics 2022-12-27 S. I. Kruglov

We propose a new cosmological paradigm in which our observed expanding phase is originated from an initially large contracting Universe that subsequently experienced a bounce. This category of models, being geodesically complete, is…

General Relativity and Quantum Cosmology · Physics 2008-11-07 Patrick Peter , Nelson Pinto-Neto

We develop a cosmological model where primordial inflation is driven by a 'solid', defined as a system of three derivatively coupled scalar fields obeying certain symmetries and spontaneously breaking a certain subgroup of these. The…

High Energy Physics - Theory · Physics 2015-06-11 Solomon Endlich , Alberto Nicolis , Junpu Wang

In this paper, we investigate the evolution of the early universe within an emergent fractional cosmological framework. The underlying formulation is conceptually rooted in generalized measure constructions, closely related to fractal…

General Relativity and Quantum Cosmology · Physics 2026-04-16 S. M. M. Rasouli

The braneworld cosmology, in which our universe is imbedded as a hypersurface in a higher dimensional bulk, has the peculiar property that the inflationary consistency relation derived in a four-dimensional cosmology persists. This…

Astrophysics · Physics 2008-04-22 David Seery , Andy Taylor

Based on the effective field theory (EFT) of nonsingular cosmologies, we build a stable model, without the ghost and gradient instabilities, of bounce inflation (inflation is preceded by a cosmological bounce). We perform a full simulation…

Cosmology and Nongalactic Astrophysics · Physics 2018-06-06 Yong Cai , Yu-Tong Wang , Jin-Yun Zhao , Yun-Song Piao

Cosmological equations for homogeneous isotropic models filled by scalar fields and ultrarelativistic matter are investigated in the framework of gauge theories of gravity. Regular inflationary cosmological models of flat, closed and open…

General Relativity and Quantum Cosmology · Physics 2014-11-17 A. V. Minkevich

Inflationary models, especially those with plateau-type potentials, are consistent with the cosmological data, but inflation itself does not resolve the initial singularity. This singularity is resolved, for example, by the idea of the…

General Relativity and Quantum Cosmology · Physics 2024-05-16 Hiroki Matsui , Alexandros Papageorgiou , Fuminobu Takahashi , Takahiro Terada