Sobolev extremal polynomials with respect to mutually singular measures

A. Diaz Gonzalez, G. Lopez Lagomasino, H. Pijeira Cabrera

We consider extremal polynomials with respect to a Sobolev-type $p$-norm, with $1<p<\infty$ and measures supported on compact subsets of the real line. For a wide class of such ext…