Abstract:
We will study bifurcations within holomorphic families of polynomials or rational maps by mean of ergodic and pluripotential theoretic tools. Around 2000, a decisive achievement was made by DeMarco: in any holomorphic family of rational maps, the bifurcation locus is the support of a (1, 1) closed positive current Tbif admiting the Lyapunov exponent function as a global potential. In the recent years, several authors have investigated the geometry of the bifurcation locus using the current Tbif . We shall present here some of the these important results. The course will be informal and we will pay particular attention to the basics of the theories involved: complex analysis in several variables, differentiable forms and currents.