Regular Seminar Iosif Bena (Saclay)
room G.O. Jones 610
Antibranes in backgrounds that have charge dissolved in fluxes are a key ingredient in constructing a landscape (Multiverse) of deSitter vacua in String Theory, and also of constructing microstate solutions corresponding to non-supersymmetric near-extremal black holes. There are several regimes of parameters in which one can study the physics of these antibranes, and I will show that in the regime of parameters where their gravitational backreaction is important, antibranes have a naked singularity that cannot be resolved either by brane polarization or by cloaking with a black hole horizon, and that signals a tachyonic instability. I will also present recent evidence that the theory on the wordvolume of anti-D3 branes is finite to all loops. I will conclude by discussing the implications of these results for the Multiverse paradigm and for the Fuzzball proposal.