Effective bounds on singular surfaces in positive characteristic

Abstract

Using the theory of Frobenius singularities, we show that 13mK_X + 45mA is very ample for an ample Cartier divisor A on a Kawamata log terminal surface X with Gorenstein index m, defined over an algebraically closed field of characteristic p>5.

arXiv commentv3: some proofs simplified and shortened (thanks to the referee), to appear in the Michigan Mathematical Journal