Other

I explain what physicists mean when they say that space and time may be relational and discuss the extent to which different of the contemporary attempts at quantum gravity satisfy this criteria. I then discuss how the current debates between advocates of background dependent and background independent theories may be seen in the light of the historical debate in philosophy between advocates of absolute and relational notions of space and time.

We will see how generalized Calabi-Yau manifolds as defined by Hitchin emerge from supersymmetry equations in type II theories. In the first lecture, we will review the formalism of G-structures, which is central in the context of compactification with fluxes. In the second lecture we will see how (twisted) generalized Calabi-Yau manifolds emerge from supersymmetry equations using SU(3) structure. In the last lecture, we will discuss special features about compactifications on Generalized Calabi-Yau's.