Metric-Palatini gravity unifying local constraints and late-time cosmic acceleration
Tiberiu HarkoDepartment of Physics and Center for Theoretical and Computational Physics, The University of Hong Kong, Pok Fu Lam Road, Hong KongTomi KoivistoInstitute for Theoretical Physics and Spinoza Institute, Utrecht University, Leuvenlaan 4, 3584 CE Utrecht, The NetherlandsFrancisco S. N. LoboCentro de Astronomia e Astrofísica da Universidade de Lisboa, Campo Grande, Edifício C8 1749-016 Lisboa, PortugalGonzalo J. OlmoDepartamento de Física Teórica and IFIC, Centro Mixto Universidad de Valencia - CSIC. Universidad de Valencia, Burjassot-46100, Valencia, Spain
2012en
ABI
Annotatsiya
We present a novel approach to modified theories of gravity which consists of adding to the Einstein-Hilbert Lagrangian an $f(\mathcal{R})$ term constructed \`a la Palatini. Using the respective dynamically equivalent scalar-tensor representation, we show that the theory can pass the Solar System observational constraints even if the scalar field is very light. This implies the existence of a long-range scalar field, which is able to modify the cosmological and galactic dynamics but leaves the Solar System unaffected. We also verify the absence of instabilities in perturbations and provide explicit models which are consistent with local tests and lead to the late-time cosmic acceleration.
Hali tarjima qilinmagan
Identifikatorlar
Iqtiboslar va manbalar
4 ta iqtibos0 ta foydalanilgan manba