Involutions of second kind on Shimura surfaces and surfaces of general type with q=p_g=0

Quaternionic Shimura surfaces are quotient of the bidisc by an irreducible cocompact arithmetic group. In the present paper we are interested in (smooth) quaternionic Shimura surfaces admitting an automorphism with one dimensional fixed locus; such automorphisms are involutions. We propose a new construction of surfaces of general type with $q=p_{g}=0$ as quotients of quaternionic Shimura surfaces by such involutions. These quotients have finite fundamental group.