4 papers
A Semi-Smooth Kodaira Vanishing Theorem and Demi-Normal Cyclic Covering Lemma
Jeremy Berquist
The classical Kodaira Vanishing Theorem states that Hi(X, ωX \otimes L) = 0 for i > 0, where X is a smooth projective variety over C and L is an ample line bundle on X. We prove an…
Demi-Normal Surface Singularities
Jeremy Berquist
We prove semi-rationalification and semi-log-canonicalization for Gorenstein demi-normal surfaces. That is, given a Gorenstein demi-normal surface X with semi-rational (respectivel…
Singularities on Demi-Normal Varieties
Jeremy Berquist
The birational classification of varieties inevitably leads to the study of singularities. The types of singularities that occur in this context have been studied by Mori, Kollár,…
Rational and Semi-Rational Singularities
Jeremy Berquist
It is a conjecture of Kollár that a variety with rational singularities in some open subvariety has a rationalification; that is, a proper, birational morphism $f: Y \right…