Publication:
Vector perturbations in bouncing cosmology

Дата
2020
Авторы
Pinto-Neto, N.
Fabris, J. C.
Toniato, J. D.
Vicente, G. S.
Journal Title
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Volume Title
Издатель
Научные группы
Организационные подразделения
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Организационная единица
Институт ядерной физики и технологий
Цель ИЯФиТ и стратегия развития - создание и развитие научно-образовательного центра мирового уровня в области ядерной физики и технологий, радиационного материаловедения, физики элементарных частиц, астрофизики и космофизики.
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Аннотация
An old question surrounding bouncing models concerns their stability under vector perturbations. Considering perfect fluids or scalar fields, vector perturbations evolve kinematically as a(-2), where a is the scale factor. Consequently, a definite answer concerning the bounce stability depends on an arbitrary constant, therefore, there is no definitive answer. In this paper, we consider a more general situation where the primeval material medium is a nonideal fluid, and its shear viscosity is capable of producing torque oscillations, which can create and dynamically sustain vector perturbations along cosmic evolution. In this framework, it can be defined that vector perturbations have a quantum mechanical origin, coming from quantum vacuum fluctuations in the far past of the bouncing model, as it is done with scalar and tensor perturbations. Under this prescription, one can calculate their evolution during the whole history of the bouncing model, and precisely infer the conditions under which they remain linear before the expanding phase. It is shown that such linearity conditions impose constraints on the free parameters of bouncing models, which are mild, although not trivial, allowing a large class of possibilities. Such conditions impose that vector perturbations are also not observationally relevant in the expanding phase. The conclusion is that bouncing models are generally stable under vector perturbations. As they are also stable under scalar and tensor perturbations, we conclude that bouncing models are generally stable under perturbations originated from quantum vacuum perturbations in the far past of their contracting phase.
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Цитирование
Vector perturbations in bouncing cosmology / Pinto-Neto, N [et al.] // Physical Review D. - 2020. - 101. - № 12. - 10.1103/PhysRevD.101.123519
URI
https://www.doi.org/10.1103/PhysRevD.101.123519
 https://www.scopus.com/record/display.uri?eid=2-s2.0-85087001478&origin=resultslist
 http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=Alerting&SrcApp=Alerting&DestApp=WOS_CPL&DestLinkType=FullRecord&UT=WOS:000540912900004
 https://openrepository.mephi.ru/handle/123456789/21945
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