On approximating submanifolds by algebraic sets and a solution to the Nash conjecture.
Without relying on the classification of compact complex surfaces, it is proved that every such surface with even first Betti number admits a Kähler metric and that a real form of the classical Nakai-Moishezon criterion holds on the surface.
We construct closed complex submanifolds of which are differential but not holomorphic complete intersections. We also prove a homotopy principle concerning the removal of intersections with certain complex subvarieties of .
In this short survey, we would like to overview the recent development of the study on Deligne-Malgrange lattices and resolution of turning points for algebraic meromorphic flat bundles. We also explain their relation with wild harmonic bundles. The author hopes that it would be helpful for access to his work on wild harmonic bundles.
Let be an algebraic variety in and when is an integer then denotes all holomorphic functions on satisfying for all and some constant . We estimate the least integer such that every admits an extension from into by a polynomial , of degree at most. In particular is related to cohomology groups with coefficients in coherent analytic sheaves on . The existence of the finite integer is for example an easy consequence of Kodaira’s Vanishing Theorem.
We give a characterization of the irreducible components of a Weierstrass-type (W-type) analytic (resp. algebraic, Nash) variety in terms of the orbits of a Galois group associated in a natural way to this variety. Since every irreducible variety of pure dimension is (locally) a component of a W-type variety, this description may be applied to any such variety.