Flavio Tonioni (Liverpool): Misaligned Supersymmetry and Anti-D-branes

In this talk, I will review the concept of misaligned supersymmetry and discuss its relationship with anti-D-branes in type II string theories.
Misaligned supersymmetry characterises a variety of non-supersymmetric string models: even if the particle spectrum lacks a one-by-one matching between particles with a different spin, there exist theories in which an infinite oscillation between fermionic and bosonic surpluses at each mass level results in a net cancellation that allows for a finite one-loop cosmological constant.
Such a scenario is often discussed with regard to closed-string theories, but I will show that the spectrum of an anti-D-brane on top of an orientifold plane presents essentially the same properties.
Anti-D-branes are crucial tools in many phenomenological string-theory realisations of features such as supersymmetry breaking and de Sitter uplifting, and I will comment on how an understanding of the effects of their infinite tower of states is related to their low-energy descriptions.