Diophantine approximation and deformation, by M. Kim, D. Thakur, J. F. Voloch

We associate certain curves over function fields to given algebraic power series and show that bounds on the rank of Kodaira-Spencer map of this curves imply bounds on the exponents of the power series, with more generic curves giving lower exponents. If we transport Vojta's conjecture on height inequality to finite characteristic by modifying it by adding suitable deformation theoretic condition, then we see that the numbers giving rise to general curves approach Roth's bound. We also prove a hierarchy of exponent bounds for approximation by algebraic quantities of bounded degree.

M. Kim, D. Thakur, J. F. Voloch <kim@math.arizona.edu, thakur@math.arizona.edu, voloch@math.utexas.edu>