On \'Ecalle-Hakim's theorems in holomorphic dynamics

In this survey we provide detailed proofs for the results by Hakim regarding the dynamics of germs of biholomorphisms tangent to the identity of order $k+1\ge 2$ and fixing the origin.Comment: 58 pages; revised version accepted in Proceedings of "Frontiers in Complex Dynamics

Wolff-Denjoy theorems in non-smooth convex domains

We give a short proof of Wolff-Denjoy theorem for (not necessarily smooth) strictly convex domains. With similar techniques we are also able to prove a Wolff-Denjoy theorem for weakly convex domains, again without any smoothness assumption on the boundary.Comment: 13 page

Toeplitz operators and Carleson measures in strongly pseudoconvex domains

We study mapping properties of Toeplitz operators associated to a finite positive Borel measure on a bounded strongly pseudoconvex domain D in n complex variables. In particular, we give sharp conditions on the measure ensuring that the associated Toeplitz operator maps the Bergman space A^p(D) into A^r(D) with r>p, generalizing and making more precise results by Cuckovic and McNeal. To do so, we give a geometric characterization of Carleson measures and of vanishing Carleson measures of weighted Bergman spaces in terms of the intrinsic Kobayashi geometry of the domain, generalizing to this setting results obtained by Kaptanoglu for the unit ball.Comment: 36 page

Dynamics of two-resonant biholomorphisms

International audienceIn this paper, we study the existence of basins of attraction for germs of tworesonant biholomorphisms of $\mathbb{C}^n$ fixing a point, that is germs such that the eigenvalues of the differential at the fixed point have a two dimensional family of resonances

Wolff-Denjoy theorems in nonsmooth convex domains

International audienceWe give a short proof of Wolff-Denjoy theorem for (not necessarily smooth) strictly convex domains. With similar techniques we are also able to prove a Wolff-Denjoy theorem for weakly convex domains, again without any smoothness assumption on the boundary

Geometrical methods in the normalization of germs of biholomorphisms

In this thesis we use geometrical methods to study the linearization and the normalization problems for germs of biholomorphisms in several complex variables, discussing both the formal level and convergence issues. We first present a survey on local holomorphic discrete dynamics, focusing our attention on linearization and normalization problems. After fixing the setting and the notation, we deal with the one-dimensional case, and then with the multi-dimensional case. Among other things, we present a new proof of a linearization result in presence of resonances, originally proved by R\"ussmann under a slightly different arithmetic hypothesis. We then deal with the linearization problem in presence of resonances. In particular we find, under certain arithmetic conditions on the eigenvalues and some restrictions on the resonances, that a necessary and sufficient condition for holomorphic linearization in presence of resonances is the existence of a particular invariant complex manifold. Moreover such a result has as corollaries most of the known linearization results. Next, we explore in our setting the consequences of the general heuristic principle saying that if a map f commutes with a map g, then some properties of g might be inherited by f, and we show how commuting with a linearizable germ gives us information on the germs that can be conjugated to a given one. For instance, one possible generalization of the linearization problem is to ask when a given set of m > 1 germs of biholomorphisms at the same fixed point, which we may place at the origin, are simultaneously holomorphically linearizable, i.e., there exists a local holomorphic change of coordinates conjugating each of them to its linear part. We find that if the germs of biholomorphisms have diagonalizable linear part and are such that the first one commutes with all the others, under certain arithmetic conditions on the eigenvalues and some restrictions on their resonances, the germs are simultaneously holomorphically linearizable if and only if there exists a particular complex manifold invariant under them. Finally we study commutations with a particular kind of linearizable object: torus actions. We find out in a complete and computable manner what kind of structure a torus action must have in order to give a Poincar\'e-Dulac holomorphic normalization, studying the possible torsion phenomena. In particular, we link the eigenvalues of the linear part of our germ of biholomorphism to the weight matrix of the action. The link and the structure we find are more complicated than what one would expect; a detailed study is needed to completely understand the relations between torus actions, holomorphic Poincar\'e-Dulac normalizations, and torsion phenomena. We end our work giving an example of techniques that can be used to construct torus actions