Can dark energy emerge from quantum effects in a compact extra dimension?

par Brahim Lamine (IRAP, Toulouse)

lundi 2 déc. 2013, 14:00 → 15:00 Europe/Paris

Amphiteatre (CPPM)

The acceleration of the expansion can now be regarded as established beyond reasonable doubt. However, the physical origin of this acceleration remains a puzzling problem in fundamental physics. Here we present a revival of an old proposition: that the origin of cosmic acceleration is due to the gravitational active vacuum. Indeed, in the presence of additional dimensions of space, a non vanishing contribution from the vacuum through a Casimir-like effect of the gravitational field can arise connecting the observed present day value of the dark energy density to high energy scale of the order of TeV. Furthermore, the equation of state of such a component is exactly those of a cosmological constant. Assuming that the Hubble radius acts as an effective boundary condition allows for such a contribution to be positive. The consequences of this model are briefly discussed