論文

査読有り
2014年3月

Master equation for the Unruh-DeWitt detector and the universal relaxation time in de Sitter space

PHYSICAL REVIEW D
  • Masafumi Fukuma
  • ,
  • Sotaro Sugishita
  • ,
  • Yuho Sakatani

89
6
開始ページ
064024
終了ページ
記述言語
英語
掲載種別
研究論文(学術雑誌)
DOI
10.1103/PhysRevD.89.064024
出版者・発行元
AMER PHYSICAL SOC

We derive the master equation that completely determines the time evolution of the density matrix of the Unruh-DeWitt detector in an arbitrary background geometry. We apply the equation to reveal a nonequilibrium thermodynamic character of de Sitter space. This generalizes an earlier study on the thermodynamic property of the Bunch-Davies vacuum that an Unruh-DeWitt detector staying in the Poincare patch and interacting with a scalar field in the Bunch-Davies vacuum behaves as if it is in a thermal bath of finite temperature. In this paper, instead of the Bunch-Davies vacuum, we consider a class of initial states of scalar field, for which the detector behaves as if it is in a medium that is not in thermodynamic equilibrium and that undergoes a relaxation to the equilibrium corresponding to the Bunch-Davies vacuum. We give a prescription for calculating the relaxation times of the nonequilibrium processes. We particularly show that, when the initial state of the scalar field is the instantaneous ground state at a finite past, the relaxation time is always given by a universal value of half the curvature radius of de Sitter space. We expect that the relaxation time gives a nonequilibrium thermodynamic quantity intrinsic to de Sitter space.

Web of Science ® 被引用回数 : 8

リンク情報
DOI
https://doi.org/10.1103/PhysRevD.89.064024
Web of Science
https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=JSTA_CEL&SrcApp=J_Gate_JST&DestLinkType=FullRecord&KeyUT=WOS:000333107900005&DestApp=WOS_CPL
URL
http://orcid.org/0000-0001-8146-5034

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