Cascading Gravity and the Accelerated Expansion of the Universe

by Oriol Pujolas Boix

Tuesday 24 Mar 2009, 11:00 → 12:00 Europe/Zurich

LAPTH Auditorium, Annecy-le-Vieux (LAPTH Auditorium, Annecy-le-Vieux)

The current Accelerated Expansion of the Universe is one of the most important puzzles in modern cosmology. It implies that either the Universe is dominated by a Cosmological Constant (or some other form of Dark Energy) or that gravity is modified in the infrared. The main challenge in Modified Gravity is whether the new gravitational dynamics can give rise to Self-Acceleration, a phase where the Universe accelerates even without Dark Energy. The Dvali-Gabadadze-Porrati model represents the first known example of consistent IR modification of gravity, but in the Self-Accelerated branch the theory has ghosts. I will review the Cascading Gravity model, a new consistent example of modified gravity in higher dimensions. I will discuss the possible realization of Self-Acceleration without ghosts in this model. Renseignements : F. Arleo, C. Boehm