Talk detail

Participant	Coelho, Flavio
Institution	University of Aveiro - Campus de Santiago - Aveiro - Aveiro - Portugal

Session	AT2	Accepted	Yes	Order	10	Time	20'
Talk	Oral abstract	Title	n-DBI Gravity
Co-authors	Carlos Herdeiro, Shinji Hirano, Yuki Sato
Abstract	We present a new model of gravity based on the Dirac-Born-Infeld type conformal scalar theory. This theory naturally predicts the primordial inflation phase of the Universe, followed by radiation- and matter-dominated epochs and subsequent accelerated expansion, without invoking any scalar field agent of inflation. Moreover, it breaks Lorentz invariance by the introduction of an everywhere time-like vector field, which specifies a physically meaningful foliation. This reduced gauge freedom gives rise to an extra (scalar) degree of freedom. In this talk we address the cosmological implications of this theory on the inflation and cosmological constant problems, present some black hole solutions and analyze the dynamics of scalar mode. We show that the scalar mode is well behaved, and does not possess the pathologies present in other Lorentz-violating theories of gravity.