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Arrow of time in dissipationless cosmologyстатья
Статья опубликована в высокорейтинговом журнале
Информация о цитировании статьи получена из
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Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 11 ноября 2015 г.
- Авторы: Sahni Varun, Shtanov Yuri, Toporensky Aleksey
- Журнал: Classical and Quantum Gravity
- Том: 32
- Номер: 18
- Год издания: 2015
- Издательство: IOP Publishing
- Местоположение издательства: [Bristol, UK], England
- Первая страница: 182001
- DOI: 10.1088/0264-9381/32/18/182001
- Аннотация: t is generally believed that a cosmological arrow of time must be associated with entropy production. Indeed, in his seminal work on cyclic cosmology, Tolman introduced a viscous fluid in order to make successive expansion/contraction cycles larger than previous ones, thereby generating an arrow of time. However, as we demonstrate in this letter, the production of entropy is not the only means by which a cosmological arrow of time may emerge. Remarkably, systems which are dissipationless may nevertheless demonstrate a preferred direction of time provided they possess attractors. An example of a system with well defined attractors is scalar-field driven cosmology. In this case, for a wide class of potentials (especially those responsible for inflation), the attractor equation of state during expansion can have the form p \simeq -\rho, and during contraction p \simeq \rho. If the resulting cosmology is cyclic, then the presence of cosmological hysteresis, \oint p~dV \neq 0 during successive cycles, causes an arrow of time to emerge in a system which is formally dissipationless. An important analogy is drawn between the arrow of time in cyclic cosmology and an arrow of time in an N-body system of gravitationally interacting particles. We find that, like the N-body system, a cyclic universe can evolve from a single past into two futures with oppositely directed arrows of time.
- Добавил в систему: Топоренский Алексей Владимирович