arXiv subjects

Kungho Chan

Publications and source records attributed to Kungho Chan.

2 recordsLinked to original sources

arXiv2008

A lower bound on Seshadri constants of hyperplane bundles on threefolds

We give the lower bound on Seshadri constants for the case of very ample line bundles on threefolds. We consider the situation when the Seshadri constant is strictly less than 2 and give a version of Bauer's theorem \cite[Theorem 2.1]{B1} for singular surfaces so we can prove the same result for smooth threefolds.

math.AG↗

arXiv2008

A characterization of double covers of curves in terms of the ample cone of second symmetric product

We investigate the nef cone spanned by the diagonal and the fibre classes of second symmetric product of a curve of genus $g$. This 2-dimensional nef cone gives a characterization of double covers of curves of genus $\le \frac{g-1}{8}$. This is a generalization of a result by Debarre.

math.AG↗