Publication:
Using Cosmological Perturbation Theory to Distinguish between GR and Unimodular Gravity

Дата
2023
Авторы
Fabris, J. C.
Alvarenga, M. H.
Velten, H.
Journal Title
Journal ISSN
Volume Title
Издатель
Научные группы
Организационные подразделения
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.
Выпуск журнала
Аннотация
Unimodular gravity is one of the oldest geometric gravity theories and alternatives to general relativity. Essentially, it is based on the Einstein–Hilbert Lagrangian with an additional constraint on the determinant of the metric. It can be explicitly shown that unimodular gravity can be recast as general relativity in the presence of a cosmological constant. This fact has led to many discussions on the equivalence of both theories at the classical and quantum levels. Here, we present an analysis focused on the classical scalar perturbations around a cosmological background. We focus on the unusual situation in which the typical conservation laws are not adopted. The discussion is extended to the case where a non-minimal coupled scalar field is introduced. We also present a gauge-invariant analysis showing that perturbations in unimodular gravity display instabilities. Our results reinforce that the equivalence is not verified completely at a cosmological perturbative level.
Описание
Ключевые слова
Unimodular matrix , f(R) gravity , Einstein Gravity , Cosmological constant , Friedmann–Lemaître–Robertson–Walker metric
Цитирование
Fabris, J. C. Using Cosmological Perturbation Theory to Distinguish between GR and Unimodular Gravity / Fabris, J. C., Alvarenga, M. H., Velten, H. // Symmetry. - 2023. - 15. - № 7. - 10.3390/sym15071392
Коллекции