A criterion for extending meromorphic functions.
Let be a smooth projective curve defined over an algebraically closed field , and let denote the absolute Frobenius morphism of when the characteristic of is positive. A vector bundle over is called virtually globally generated if its pull back, by some finite morphism to from some smooth projective curve, is generated by its global sections. We prove the following. If the characteristic of is positive, a vector bundle over is virtually globally generated if and only if for...
Si costruiscono curve di genere , che hanno fasci semicanonici tali che . Per si dimostra che gli sono molto ampi.
We introduce and study a deformation of commutative polynomial algebras in even numbers of variables. We also discuss some connections and applications of this deformation to the generalized Laguerre orthogonal polynomials and the interchanges of right and left total symbols of differential operators of polynomial algebras. Furthermore, a more conceptual re-formulation for the image conjecture [18] is also given in terms of the deformed algebras. Consequently, the well-known Jacobian conjecture...
Let be a local field of residue characteristic . Let be a curve over whose minimal proper regular model has totally degenerate semi-stable reduction. Under certain hypotheses, we compute the prime-to- rational torsion subgroup on the Jacobian of . We also determine divisibility of line bundles on , including rationality of theta characteristics and higher spin structures. These computations utilize arithmetic on the special fiber of .