| Автор | Antonio De Felice |
| Автор | Teruaki Suyama |
| Дата выпуска | 2009-06-01 |
| dc.description | We have found for the general class of Modified Gravity Models f(R, G) a new instability which can arise in vacuum for the scalar modes of the cosmological perturbations if the background is not de Sitter. In particular, the short-wavelength modes, if stable, in general have a group velocity which depends linearly in k, the wave number. Therefore these modes will be in general superluminal. We have also discussed the condition for which in general these scalar modes will be ghost-like. There is a subclass of these models, defined out of properties of the function f(R, G) and to which the f(R) and f(G) models belong, which however do not have this feature. |
| Формат | application.pdf |
| Издатель | Institute of Physics Publishing |
| Название | Vacuum structure for scalar cosmological perturbations in modified gravity models |
| Тип | paper |
| DOI | 10.1088/1475-7516/2009/06/034 |
| Electronic ISSN | 1475-7516 |
| Журнал | Journal of Cosmology and Astroparticle Physics |
| Том | 2009 |
| Первая страница | 34 |
| Последняя страница | 034 |
| Аффилиация | Antonio De Felice; Theoretical and Mathematical Physics Group, Centre for Particle Physics and Phenomenology, Louvain University, 2 Chemin du Cyclotron, 1348 Louvain-la-Neuve, Belgium |
| Аффилиация | Teruaki Suyama; Theoretical and Mathematical Physics Group, Centre for Particle Physics and Phenomenology, Louvain University, 2 Chemin du Cyclotron, 1348 Louvain-la-Neuve, Belgium |
| Выпуск | 06 |
