Conditions for the cosmological viability of the most general scalar-tensor theories and their applications to extended Galileon dark energy models

Дата и время публикации : 2011-10-18T05:22:45Z

Авторы публикации и институты :
Antonio De Felice
Shinji Tsujikawa

Ссылка на журнал-издание: JCAP 1202:007, 2012
Коментарии к cтатье: 18 pages, 6 figures
Первичная категория: gr-qc

Все категории : gr-qc, astro-ph.CO, hep-ph, hep-th

Краткий обзор статьи: In the Horndeski’s most general scalar-tensor theories with second-order field equations, we derive the conditions for the avoidance of ghosts and Laplacian instabilities associated with scalar, tensor, and vector perturbations in the presence of two perfect fluids on the flat Friedmann-Lemaitre-Robertson-Walker (FLRW) background. Our general results are useful for the construction of theoretically consistent models of dark energy. We apply our formulas to extended Galileon models in which a tracker solution with an equation of state smaller than -1 is present. We clarify the allowed parameter space in which the ghosts and Laplacian instabilities are absent and we numerically confirm that such models are indeed cosmologically viable.

Category: Physics