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We study the dynamics of a non-minimally coupled scalar field cosmology with a potential function. We use the framework of dynamical systems theory to investigate all evolutional paths admissible for all initial conditions. Additionally, we…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Orest Hrycyna , Marek Szydlowski

The cosmological term, $\Lambda$, in Einstein's equations is an essential ingredient of the `concordance' $\Lambda$CDM model of cosmology. In this mini-review presentation, we assess the possibility that $\Lambda$ can be a dynamical…

General Relativity and Quantum Cosmology · Physics 2022-07-19 Joan Sola Peracaula

A substantial body of phenomenological and theoretical work over the last few years strengthens the possibility that the vacuum energy density (VED) of the universe is dynamical, and in particular that it adopts the `running vacuum model'…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-31 Joan Sola Peracaula , Adria Gomez-Valent , Javier de Cruz Perez , Cristian Moreno-Pulido

We study the dynamics of homogeneous and isotropic Friedmann-Lema\^itre-Robertson-Walker cosmological models with positive spatial curvature within the context of mimetic gravity theory by employing dynamical system techniques. Our analysis…

General Relativity and Quantum Cosmology · Physics 2024-09-18 Alberto Fritis , Daniel Villalobos-Silva , Yerko Vásquez , Carlos H. López-Caraballo , Juan Carlos Helo

We investigate the effects of scale-free model on cosmology, providing, in this way, a statistical background in the framework of general relativity. In order to discuss properties and time evolution of some relevant universe dynamical…

General Relativity and Quantum Cosmology · Physics 2015-05-13 Orlando Luongo , Carmine Autieri

By means of the present geometrical and dynamical observational data, it is very hard to establish, from a statistical perspective, a clear preference among the vast majority of the proposed models for the dynamical dark energy and/or…

Cosmology and Nongalactic Astrophysics · Physics 2017-11-07 Tomasz Denkiewicz , Vincenzo Salzano

We phenomenologically derive a cosmological model that includes both a cosmological constant term $\Lambda/3$ and a dissipative driving term $\beta (2 H^{2} + \dot{H})$ by applying both the first law of thermodynamics and an effective…

General Relativity and Quantum Cosmology · Physics 2026-03-30 Nobuyoshi Komatsu

We consider cosmological dynamics in the theory of gravity with the scalar field possessing the nonminimal kinetic coupling to curvature given as $\eta G^{\mu\nu}\phi_{,\mu}\phi_{,\nu}$, where $\eta$ is an arbitrary coupling parameter, and…

General Relativity and Quantum Cosmology · Physics 2018-01-24 Jiro Matsumoto , Sergey V. Sushkov

Cosmological models in Lyra's geometry are constructed and investigated with the assumption of a minimal interaction of matter with the displacement vector field and the dynamical $\Lambda$ - term. Exact solutions of the model equations are…

General Relativity and Quantum Cosmology · Physics 2012-10-04 V. K. Shchigolev

In the context of a family os scalar-tensor theories with a dynamical $\Lambda$, that is a binomial on the scalar field, the cosmological equations are considered. A general barotropic state equation $p=(\gamma-1)\rho$, for a perfect fluid…

General Relativity and Quantum Cosmology · Physics 2009-10-31 L. M. Diaz-Rivera , L. O. Pimentel

Recent observations of Type 1a supernovae indicating an accelerating universe have once more drawn attention to the possible existence, at the present epoch, of a small positive Lambda-term (cosmological constant). In this paper we review…

Astrophysics · Physics 2009-10-31 Varun Sahni , Alexei Starobinsky

In this paper, the dynamical behavior of the accelerated expansion of the universe is discussed within the framework of $f(T)$ gravity, considering power law functional form of $ f(T)=\alpha (-T)^{n}$. Two distinct redshift-dependent…

General Relativity and Quantum Cosmology · Physics 2025-08-29 Shivank Pal , Romanshu Garg , Gyan Prakash Singh , Gauree Shanker

This paper explores cosmological scenarios in a scalar-tensor theory of gravity, including both a non-minimal coupling with scalar curvature of the form $R\phi^2$ and a non-minimal derivative coupling of the form…

General Relativity and Quantum Cosmology · Physics 2025-10-13 Ravil R. Fatykhov , Sergey V. Sushkov

We consider a $D$-dimensional Einstein-Gauss-Bonnet model with a cosmological term $\Lambda$ and two non-zero constants: $\alpha_1$ and $\alpha_2$. We restrict the metrics to be diagonal ones and study a class of solutions with exponential…

General Relativity and Quantum Cosmology · Physics 2020-07-15 K. K. Ernazarov , V. D. Ivashchuk

On the basis of the general relativistic statistical and kinetic theory, a consistent closed cosmological model is formulated. It is based on a statistical system of scalar charged fermions interacting by means of classical and phantom…

General Relativity and Quantum Cosmology · Physics 2021-11-02 Yu. G. Ignat'ev , D. Yu. Ignatyev

The paper presents the transition of universe from early decelerating phase to current accelerating phase with viscous fluid and time dependent cosmological constant $(\Lambda)$ as source of matter in Bianchi-V space-time. To study the…

General Physics · Physics 2012-07-06 Anil Kumar Yadav

We shall present a complete (compactified) dynamical systems analysis of the Quintom model comprised of an interacting quintessence scalar field and a phantom. We find a range for the model parameters $\kappa, \lambda$ such that there are…

General Relativity and Quantum Cosmology · Physics 2022-11-21 Jonathan Tot , Balkar Yildirim , Alan Coley , Genly Leon

We propose a new cosmological model with a time-dependent cosmological constant ($\Lambda\propto 1/t^2$), which starting at the Planck time as $\Lambda_{Pl}\sim M^2_{Pl}$, evolves to the present-day allowed value of…

High Energy Physics - Phenomenology · Physics 2016-09-01 J. Lopez , D. Nanopoulos

In this article, we examine the dynamical evolution of flat FRW cosmological model in $f(R, L_m)$ gravity theory. We consider the general form of $f(R, L_m)$ defined as $f(R, L_m) = \Lambda + \frac{\alpha}{2} R + \beta L_m^n$, where…

General Relativity and Quantum Cosmology · Physics 2025-02-14 Aman Shukla , Rakesh Raushan , Raghavendra Chaubey

We consider a dynamical systems formulation for models with an exponential scalar field and matter with a linear equation of state in a spatially flat and isotropic spacetime. In contrast to earlier work, which only considered linear…

General Relativity and Quantum Cosmology · Physics 2022-07-13 Artur Alho , Woei Chet Lim , Claes Uggla