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Related papers: Emergent Spacetime and Cosmic Inflation

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We study a class of non-local, action-based, and purely gravitational models. These models seek to describe a cosmology in which inflation is driven by a large, bare cosmological constant that is screened by the self-gravitation between the…

General Relativity and Quantum Cosmology · Physics 2016-08-17 N. C. Tsamis , R. P. Woodard

Cosmic inflation is arguably the most favoured paradigm of the very early Universe. It postulates an early phase of fast, nearly exponential, and accelerated expansion. Inflationary models are capable of explaining the overall flatness and…

Cosmology and Nongalactic Astrophysics · Physics 2022-11-08 Cristian Joana

We present an introduction to cosmic inflation in the framework of Palatini gravity, which provides an intriguing alternative to the conventional metric formulation of gravity. In the latter, only the metric specifies the spacetime…

General Relativity and Quantum Cosmology · Physics 2025-01-23 Ioannis D. Gialamas , Alexandros Karam , Thomas D. Pappas , Eemeli Tomberg

Observations of the cosmic microwave sky are revealing the primordial non-uniformities from which all structure in the Universe grew. The only known physical mechanism for generating the inhomogeneities we see involves the amplification of…

Astrophysics · Physics 2009-10-31 Neil Turok

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…

High Energy Physics - Theory · Physics 2009-11-10 Jerome Martin

We suggest a new conceptual frame where inflationary Cosmology is quantum mechanically described using the Hilbert space representation of the crossed product of the type $III$ factor associated with the algebra of local operators on the de…

High Energy Physics - Theory · Physics 2022-07-15 Cesar Gomez

We revisit an inflationary scenario in which primordial inhomogeneities arise from a quantum collapse, a stochastic mechanism described in the context of quantum collapse theories in its continuous version and within semiclassical gravity.…

General Relativity and Quantum Cosmology · Physics 2026-03-04 María Pía Piccirilli , Gabriel León , Rosa-Laura Lechuga-Solis , Daniel Sudarsky

This article provides an introductory review of inflation and cosmological perturbation theory. I begin by motivating the need for an epoch of inflation during the early stages of the radiation dominated era, and describe how inflation is…

Cosmology and Nongalactic Astrophysics · Physics 2024-07-08 L. Sriramkumar

In a unified picture both inflation and present dynamical dark energy arise from the same scalar field. The history of the Universe describes a crossover from a scale invariant "past fixed point" where all particles are massless, to a…

High Energy Physics - Theory · Physics 2015-12-09 C. Wetterich

Inflation has been the leading early universe scenario for two decades, and has become an accepted element of the successful `cosmic concordance' model. However, there are many puzzling features of the resulting theory. It requires both…

High Energy Physics - Theory · Physics 2009-11-10 Neil Turok , Paul J. Seinhardt

Many inflating spacetimes are likely to violate the weak energy condition, a key assumption of singularity theorems. Here we offer a simple kinematical argument, requiring no energy condition, that a cosmological model which is inflating --…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Arvind Borde , Alan H. Guth , Alexander Vilenkin

After a brief summary of general relativity and cosmology, we present the basic concepts underlying inflation, the currently best motivated models for the early Universe. We describe the simplest inflation models, based on a single scalar…

General Relativity and Quantum Cosmology · Physics 2008-11-27 David Langlois

We study a model of power-law inflationary inflation using the Space-Time-Matter (STM) theory of gravity for a five dimensional (5D) canonical metric that describes an apparent vacuum. In this approach the expansion is governed by a single…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Mariano Anabitarte , Mauricio Bellini

We propose a method to extract predictions from quantum cosmology for inflation that can be confronted with observations. Employing the tunneling boundary condition in quantum geometrodynamics, we derive a probability distribution for the…

General Relativity and Quantum Cosmology · Physics 2015-07-21 Gianluca Calcagni , Claus Kiefer , Christian F. Steinwachs

We present an introduction to cosmic inflation in the context of Palatini gravity, which is an interesting alternative to the usual metric theory of gravity. In the latter case only the metric $g_{\mu\nu}$ determines the geometry of…

Cosmology and Nongalactic Astrophysics · Physics 2020-04-10 Tommi Tenkanen

In this paper, we consider a nonminimal coupling model between gravity and nonlinear electrodynamics with cosmological constant. This cosmological model is designed to account for both the inflationary epoch of the early universe and the…

General Relativity and Quantum Cosmology · Physics 2024-10-10 Chilwatun Nasiroh , Ramy F. Izzah , Fiki T. Akbar , Bobby E. Gunara

Cosmic inflation provides a window to the highest energy densities accessible in nature, far beyond those achievable in any realistic terrestrial experiment. Theoretical insights into the inflationary era and its observational probes may…

We compute the spectrum of cosmological perturbations in a scenario in which inflation is driven by radiation in a non-commutative space-time. In this scenario, the non-commutativity of space and time leads to a modified dispersion relation…

High Energy Physics - Theory · Physics 2010-10-27 Seoktae Koh , Robert H. Brandenberger

Warm inflation has normalized two ideas in cosmology, that in the early universe the initial primordial density perturbations generally could be of classical rather than quantum origin and that during inflation, particle production from…

High Energy Physics - Phenomenology · Physics 2023-06-23 Arjun Berera

Inflation provides a natural mechanism to account for the origin of cosmic structures. The generation of primordial inhomogeneities during inflation can be understood via the spontaneous creation of quanta from the vacuum. We show that when…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Ivan Agullo , Leonard Parker