Fixed point theorems and strong asymptotic of multiple orthogonal polynomials

In this talk we study the strong asymptotic of multiple orthogonal polynomials associated with a mixed type Hermite–Padé approximation problem. For this purpose we adapt a method devised by A. I. Aptekarev to obtain the strong asymptotic of type II Hermite–Padé polynomials of a Nikishin system using fixed point theorems.