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Recently a class of inflationary models satisfying the constant rate of roll constraint, $\ddot{\phi}+(3+\alpha)H\dot{\phi}=0$, has been studied and compared with the latest cosmological observational data. We consider the broader class of…

General Relativity and Quantum Cosmology · Physics 2019-11-11 B. Boisseau , H. Giacomini

We derive consistency conditions for sustained slow roll and rapid turn inflation in two-field cosmological models with oriented scalar field space, which imply that inflationary models with field-space trajectories of this type are…

High Energy Physics - Theory · Physics 2023-05-18 Lilia Anguelova , Calin Iuliu Lazaroiu

In this paper we find a solution for a quasi-isotropic inflationary Universe which allows to introduce in the problem a certain degree of inhomogeneity. We consider a model which generalize the (flat) FRW one by introducing a first order…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Giovanni Paolo Imponente , Giovanni Montani

A stiff matter-dominated universe modeled by a free massless scalar field minimally coupled to gravity in a Friedmann-Lema\^{\i}tre-Robertson-Walker (FLRW) geometry is quantized. Generalized complex-width gaussian superpositions of the…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Felipe T. Falciano , Nelson Pinto-Neto , E. Sergio Santini

We develop a potential-independent cosmographic framework, in which cosmographic parameters are promoted to dynamical variables within a closed autonomous system. Although the cosmographic hierarchy is formally infinite, we achieve closure…

General Relativity and Quantum Cosmology · Physics 2026-05-13 Seturumane Tema , S. Shajidul Haque , Saurya Das , Peter Dunsby

We derive an $\alpha=1/3$ - attractor potential of slow-roll inflation in the geometric set-up of three intersecting $D7$ branes under $T^6/Z_N$ type of $CY_3$-compactification within type IIB/F theory with some near-conifold regions. The…

High Energy Physics - Theory · Physics 2024-05-01 Arunoday Sarkar , Buddhadeb Ghosh

We investigate the dynamical properties of a class of spatially homogeneous and isotropic cosmological models containing a barotropic perfect fluid and multiple scalar fields with independent exponential potentials. We show that the…

General Relativity and Quantum Cosmology · Physics 2009-10-31 A. A. Coley , R. J. van den Hoogen

In this work, we systematically present a new dynamical systems approach to standard inflationary processes and their variants as constant-roll inflation. Using the techniques presented in our work one can in general investigate the…

General Relativity and Quantum Cosmology · Physics 2026-01-13 Sandip Biswas , Saddam Hussain , Kaushik Bhattacharya

In Ref. [1], it was claimed that in the spatially flat cosmological case there exists a unique conserved measure (up to normalization) on the $(\phi,\dot{\phi})$ phase space for scalar field with $m^2\phi^2$ potential by finding a unique…

General Relativity and Quantum Cosmology · Physics 2025-10-31 Yu Han , Long Chen

We study a class of minimally coupled scalar field theories which leads to analytic solutions for the Hubble rate and the scalar field, where the scalar field obeys a generalized tracking law $\dot{\phi}^2\sim H^{-m}$. The inflationary…

General Relativity and Quantum Cosmology · Physics 2026-03-17 V. K. Oikonomou

In this letter we will study the cosmological dynamical system of an $f(R)$ gravity in the presence of a canonical scalar field $\phi$ with an exponential potential, by constructing the dynamical system in a way that it is render…

General Relativity and Quantum Cosmology · Physics 2019-01-09 K. Kleidis , V. K. Oikonomou

We analyse the evolution of the reduced density matrix of inflationary perturbations, coupled to a heavy entropic field via the leading-order term within the Effective Field Theory of Inflation, for two nearly de Sitter backgrounds. We…

High Energy Physics - Theory · Physics 2024-11-14 Suddhasattwa Brahma , Jaime Calderón-Figueroa , Xiancong Luo , David Seery

We briefly review the arising of an inflationary phase in the Universe evolution in order to discuss an inhomogeneous cosmological solution in presence of a real self interacting scalar field minimally coupled to gravity in the region of a…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Giovanni Imponente

We generalize the notion of constant-roll inflation earlier introduced in General Relativity (GR) and $f(R)$ gravity to inflationary models in more general scalar-tensor gravity. A number of novel exact analytic solutions for a FLRW…

General Relativity and Quantum Cosmology · Physics 2020-02-25 Hayato Motohashi , Alexei A. Starobinsky

Multi-field inflation with a curved scalar geometry has been found to support background trajectories that violate the slow-roll, slow-turn conditions and thus have the potential to evade the swampland constraints. In order to understand…

High Energy Physics - Theory · Physics 2020-01-08 Perseas Christodoulidis , Diederik Roest , Evangelos I. Sfakianakis

We consider inflation driven near a saddle point in a higher dimensional field space, which is the most likely type of slow roll inflation on the string theoretical landscape; anthropic arguments need to be invoked in order to find a…

High Energy Physics - Theory · Physics 2013-07-25 Diana Battefeld , Thorsten Battefeld

We explore the dynamics of multi-field models of inflation in which the field-space metric is a hyperbolic manifold of constant curvature. Such models are known as $\alpha$-attractors and their single-field regimes have been extensively…

High Energy Physics - Theory · Physics 2021-12-14 Perseas Christodoulidis , Diederik Roest , Evangelos I. Sfakianakis

We consider a cosmological model consisting of two scalar fields defined in the hyperbolic plane known as hyperbolic inflation. For the background space, we consider a homogeneous and isotropic spacetime with nonzero curvature. We study the…

General Relativity and Quantum Cosmology · Physics 2022-08-31 Andronikos Paliathanasis , Genly Leon

At high e-foldings of expansion, the inflation with the quartic potential exhibits the parametric attractor governed by the slowly running Hubble rate. This quasiattractor simplifies the analysis of predictions for the inhomogeneity…

General Relativity and Quantum Cosmology · Physics 2008-06-11 V. V. Kiselev , S. A. Timofeev

In this work we study slow-roll inflation for a vector-tensor model with massive vector fields non-minimally coupled to gravity. The model under consideration has arbitrary parameters for each geometrical coupling. Taking into account a…

General Relativity and Quantum Cosmology · Physics 2016-12-21 A. Oliveros