Thermodynamical properties of dark energy with the equation of state $% ω=ω_{0}+ω_{1}z$

Yongping Zhang; Ze-Long Yi; Tong-Jie Zhang; Wenbiao Liu

doi:10.1103/physrevd.77.023502

Home/Archive/arXiv

arXiv · 0709.2745

Thermodynamical properties of dark energy with the equation of state $% ω=ω_{0}+ω_{1}z$

Yongping Zhang·Ze-Long Yi·Tong-Jie Zhang·Wenbiao Liu

View original source ↗Read source document ↗Export metadata ↓

Abstract

The thermodynamical properties of dark energy are usually investigated with the equation of state $ω=ω_{0}+ω_{1}z$. Recent observations show that our universe is accelerating, and the apparent horizon and the event horizon vary with redshift $z$. When definitions of the temperature and entropy of a black hole are used to the two horizons of the universe, we examine the thermodynamical properties of the universe which is enveloped by the apparent horizon and the event horizon respectively. We show that the first and the second laws of thermodynamics inside the apparent horizon in any redshift are satisfied, while they are broken down inside the event horizon in some redshift. Therefore, the apparent horizon for the universe may be the boundary of thermodynamical equilibrium for the universe like the event horizon for a black hole.

Explore related subjects

astro-ph

Keep this discovery

BibTeX RIS

Yongping Zhang, Ze-Long Yi, Tong-Jie Zhang, Wenbiao Liu. 2007-10-30. Thermodynamical properties of dark energy with the equation of state $% ω=ω_{0}+ω_{1}z$. https://doi.org/10.1103/physrevd.77.023502

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2019

A new paradigm for the universe

This book provides a completely new approach to understanding the universe. The main idea is that the principal objects in the universe form a spectrum unified by the presence of a massive or hypermassive black hole. These objects are variously called quasars, active galaxies and spiral galaxies. The key to understanding their dynamics is angular momentum and the key tool, and main innovative idea of this work, is a proper formulation of "Mach's principle" using Sciama's ideas. In essence, what is provided here is a totally new paradigm for the universe. In this paradigm, there is no big bang, and the universe is many orders of magnitude older than current estimates for its age. Indeed there is no natural limit for its age.

astro-ph↗

arXiv2019

Rotation Curves of Spiral Galaxies

Rotation curves of spiral galaxies are the major tool for determining the distribution of mass in spiral galaxies. They provide fundamental information for understanding the dynamics, evolution and formation of spiral galaxies. We describe various methods to derive rotation curves, and review the results obtained. We discuss the basic characteristics of observed rotation curves in relation to various galaxy properties, such as Hubble type, structure, activity, and environment.

astro-ph↗

arXiv2018

Abrupt global events in the Earth's history: a physics perspective

The timeline of the Earth's history reveals quasi-periodicity of the geological record over the last 542 Myr, on timescales close, in the order of magnitude, to 1 Myr. What is the origin of this quasi-periodicity? What is the nature of the global events that define the boundaries of the geological time scale? I propose that a single mechanism is responsible for all three types of such events: mass extinctions, geomagnetic polarity reversals, and sea-level fluctuations. The mechanism is fast, and involves a significant energy release. The mechanism is unlikely to have astronomical causes, both because of the energies involved, and because it acts quasi-periodically. It must then be sought within the Earth itself. And it must be capable of reversing the Earth's magnetic field. The last requirement makes it incompatible with the consensus model of the origin of the geomagnetic field - the hydromagnetic dynamo operating in the Earth's fluid core. In the second part of the paper, I show that a vast amount of seemingly unconnected geophysical and geological data can be understood in a unified way if the source of the Earth's main magnetic field is a ~200-km-thick lithosphere, repeatedly magnetized as a result of methane-driven oceanic eruptions, which produce ocean flow capable of dynamo action. The eruptions are driven by the interplay of buoyancy forces and exsolution of dissolved gas, which accumulates in the oceanic water masses prone to stagnation and anoxia. Polarity reversals, mass extinctions, and sequence boundaries are consequences of these eruptions. Unlike the consensus model of geomagnetism, this scenario is consistent with the paleomagnetic data showing that "directional changes during a [geomagnetic polarity] reversal can be astonishingly fast, possibly occurring as a nearly instantaneous jump from one inclined dipolar state to another in the opposite hemisphere".

astro-ph↗