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The expansion rate of `Intermediate inflation' lies between the exponential and power law expansion but corresponding accelerated expansion does not start at the onset of cosmological evolution. Present study of `Intermediate inflation'…

天体物理学 · 物理学 2009-12-17 Abhik Kumar Sanyal

After decades of successful hot big-bang paradigm, Cosmology still lacks a framework in which the early inflationary phase of the universe smoothly matches the radiation epoch and evolves to the present `quasi' de Sitter spacetime. No less…

宇宙学与河外天体物理 · 物理学 2015-06-16 S. Basilakos , J. A. S. Lima , J. Solà

We propose a scenario that can explain the early-time inflation and the late-time dark energy within a unified framework. A scalar potential combining power-law and exponential type in a context of extended Jordan-Brans-Dicke gravity is…

宇宙学与河外天体物理 · 物理学 2024-07-15 Kunio Kaneta , Kin-ya Oda , Motohiko Yoshimura

In this seven-part paper, we show that gravitational waves (classical and quantum) produce the accelerated de Sitter expansion at the start and at the end of the cosmological evolution of the Universe. In these periods, the Universe…

综合物理 · 物理学 2017-11-16 Leonid Marochnik

We consider a novel model of cosmic inflation. In our model one does not need any specific matter field to drive inflation, but inflation stems from the microscopic, Planck scale structure of spacetime, thus being of quantum gravitational…

广义相对论与量子宇宙学 · 物理学 2014-08-28 Jarmo Mäkelä

Quantum geometry predicts that a universe evolves through an inflationary phase at small volume before exiting gracefully into a standard Friedmann phase. This does not require the introduction of additional matter fields with ad hoc…

广义相对论与量子宇宙学 · 物理学 2008-11-26 Martin Bojowald

For simple inflationary models, we provide a consistent and complete scheme by which the macro-physical details of early universe inflation may be determined explicitly from the underlying micro-physical theory. We examine inflationary…

高能物理 - 唯象学 · 物理学 2007-05-23 D. Cormier

In the framework of Born-Infeld inspired gravity theories, which deviates from General Relativity (GR) in the high curvature regime, we discuss the viability of Cosmic Inflation without scalar fields. For energy densities higher than the…

广义相对论与量子宇宙学 · 物理学 2016-03-10 Jose Beltran Jimenez , Lavinia Heisenberg , Gonzalo J. Olmo , Christophe Ringeval

It is shown here that a dynamical Planck mass can drive the scale factor of the universe to accelerate. The negative pressure which drives the cosmic acceleration is identified with the unusual kinetic energy density of the Planck field. No…

广义相对论与量子宇宙学 · 物理学 2010-11-01 Janna Levin

We construct a model of quintessential inflation in Palatini $R^2$ gravity employing a scalar field with a simple exponential potential and coupled to gravity with a running non-minimal coupling. At early times, the field acts as the…

广义相对论与量子宇宙学 · 物理学 2022-11-03 Konstantinos Dimopoulos , Alexandros Karam , Samuel Sánchez López , Eemeli Tomberg

We briefly discuss cosmic inflation, which is the dominant paradigm for the generation of the large scale structure in the Universe and also for arranging for the initial conditions of the hot Big Bang. We then present quintessential…

高能物理 - 唯象学 · 物理学 2024-03-01 Konstantinos Dimopoulos

In this paper we investigate the cosmological dynamics of geometric inflation by means of the tools of the dynamical systems theory. We focus in the study of two explicit models where it is possible to sum the infinite series of higher…

广义相对论与量子宇宙学 · 物理学 2021-03-31 Israel Quiros , Roberto De Arcia , Ricardo García-Salcedo , Tame Gonzalez , Francisco X. Linares Cedeño , Ulises Nucamendi

We study accelerating dynamics from Born-Infeld-$f(R)$ gravity in a simplified conformal approach without matter. In our work (A.N. Makarenko, S. Odintsov, G.J. Olmo, Phys.Lett. B734 (2014) 36, [arXiv:1403.2850]) it was derived eventually…

广义相对论与量子宇宙学 · 物理学 2014-07-22 Andrey N. Makarenko

This review article aims at presenting the theory of inflation. We first describe the background spacetime behavior during the slow-roll phase and analyze how inflation ends and the Universe reheats. Then, we present the theory of…

高能物理 - 理论 · 物理学 2009-11-10 Jerome Martin

A quantum field theory warm inflation model is presented that solves the horizon/flatness problems. The model obtains, from the elementary dynamics of particle physics, cosmological scale factor trajectories that begin in a radiation…

高能物理 - 唯象学 · 物理学 2008-11-26 Arjun Berera , Marcelo Gleiser , Rudnei O. Ramos

There is sufficient amount of internal evidence in the nature of gravitational theories to indicate that gravity is an emergent phenomenon like, e.g, elasticity. Such an emergent nature is most apparent in the structure of gravitational…

宇宙学与河外天体物理 · 物理学 2015-06-05 T. Padmanabhan

An exponential kind of quintessential inflation potential motivated by supergravity is studied. This type belongs to the class of {\alpha}-attractor models. The model was studied for the first time by Dimopoulos and Owen in [J. Cosmol.…

宇宙学与河外天体物理 · 物理学 2021-07-01 Llibert Aresté Saló , David Benisty , Eduardo I. Guendelman , Jaume de Haro

In the present paper, it is found that dark energy emerges spontaneously from the modified gravity. According to cosmological scenario, obtained here, the universe inflates for $\sim 10^{-37}$ sec. in the beginning and late universe…

天体物理学 · 物理学 2008-11-26 S. K. Srivastava

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…

广义相对论与量子宇宙学 · 物理学 2022-03-18 Gabriel Leon

We study inflation and late-time acceleration in the expansion of the universe in non-minimal electromagnetism, in which the electromagnetic field couples to the scalar curvature function. It is shown that power-law inflation can be…

天体物理学 · 物理学 2009-06-23 Kazuharu Bamba , Sergei D. Odintsov