Séminaire

n this talk I will present some recent results on instabilities of anti-de Sitter flux compactifications in effective field theories arising from non-supersymmetric string models, namely the USp(32) and U(32) orientifold models and the SO(16) x SO(16) heterotic string. We focus on non-perturbative instabilities, framing the vacua in terms of brane stacks, analyzing their back-reacted geometry and reproducing AdS its near-horizon limit.

Atmospheric neutrino experiments measure the oscillations of neutrinos produced in the atmosphere by default assuming unitary mixing of electron-, muon-, and tau-neutrinos. The task-list for the upcoming years involves: (a) Measure the atmospheric mixing parameters with increased precision. (b) Determine the known unknowns in the framework of three neutrino flavours: ordering of neutrino masses and CP-violation.

There are ways to cure the singularity problem in cosmology
by means of quantum effects. In the process, one encounters
the question of time, which can for instance be addressed by
using an internal degree of freedom. Applying such a method
to an anisotropic Bianchi I model where the shear serves as a
clock, I show that some generic features can be obtained for
the trajectory of the average scale factor, all avoiding the
singularity and reaching similar asymptotic states, deemed
semi-classical.