Scalar Dark Energy Models and Scalar-Tensor Gravity: Theoretical Explanations for the Accelerated Expansion of Present Universe

Fuente: arXiv
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Autori principali: Ji, Peixiang, Shao, Lijing
Natura: Preprint
Pubblicazione: 2024
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author Ji, Peixiang
Shao, Lijing
author_facet Ji, Peixiang
Shao, Lijing
contents The reason for the present accelerated expansion of the Universe stands as one of the most profound questions in the realm of science, with deep connections to both cosmology and fundamental physics. From a cosmological point of view, physical models aimed at elucidating the observed expansion can be categorized into two major classes: dark energy and modified gravity. We review various major approaches that employ a single scalar field to account for the accelerating phase of our present Universe. Dynamical system analysis is employed in several important models to seek for cosmological solutions that exhibit an accelerating phase as an attractor. For scalar field models of dark energy, we consistently focus on addressing challenges related to the fine-tuning and coincidence problems in cosmology, as well as exploring potential solutions to them. For scalar-tensor theories and their generalizations, we emphasize the importance of constraints on theoretical parameters to ensure overall consistency with experimental tests. Models or theories that could potentially explain the Hubble tension are also emphasized throughout this review.
format Preprint
id arxiv_https___arxiv_org_abs_2406_04954
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Scalar Dark Energy Models and Scalar-Tensor Gravity: Theoretical Explanations for the Accelerated Expansion of Present Universe
Ji, Peixiang
Shao, Lijing
General Relativity and Quantum Cosmology
The reason for the present accelerated expansion of the Universe stands as one of the most profound questions in the realm of science, with deep connections to both cosmology and fundamental physics. From a cosmological point of view, physical models aimed at elucidating the observed expansion can be categorized into two major classes: dark energy and modified gravity. We review various major approaches that employ a single scalar field to account for the accelerating phase of our present Universe. Dynamical system analysis is employed in several important models to seek for cosmological solutions that exhibit an accelerating phase as an attractor. For scalar field models of dark energy, we consistently focus on addressing challenges related to the fine-tuning and coincidence problems in cosmology, as well as exploring potential solutions to them. For scalar-tensor theories and their generalizations, we emphasize the importance of constraints on theoretical parameters to ensure overall consistency with experimental tests. Models or theories that could potentially explain the Hubble tension are also emphasized throughout this review.
title Scalar Dark Energy Models and Scalar-Tensor Gravity: Theoretical Explanations for the Accelerated Expansion of Present Universe
topic General Relativity and Quantum Cosmology
url https://arxiv.org/abs/2406.04954