In this thesis I present different notions of special subsets of the real line and their properties, in particular of those related to measure and convergence. We search for answers to open questions in this subject and ...

In this thesis we consider languages of infinite words or trees defined by automata of various types or formulas of various logics. We ask about the highest possible position in the Borel or the projective hierarchy inhabited ...

The following thesis is concerned with deformation theory over a perfect field of characteristic p > 0. We investigate mod p2 and characteristic zero liftability of schemes and their Frobenius morphism. In particular, we ...