On projections of smooth and nodal plane curves
Algebraic Geometry
2014-01-22 v3
Abstract
Suppose that is a general enough nodal plane curve of degree , is its normalization, and is a finite morphism simply ramified over the same set of points as a projection , where (if , one should assume in addition that ). We prove that the morphism is equivalent to such a projection if and only if it extends to a finite morphism ramified over , where is a smooth surface. As a by-product, we prove the Chisini conjecture for mappings ramified over duals to general nodal curves of any degree except for duals to smooth cubics; this strengthens one of Victor Kulikov's results.
Keywords
Cite
@article{arxiv.1311.1904,
title = {On projections of smooth and nodal plane curves},
author = {Yu. Burman and Serge Lvovski},
journal= {arXiv preprint arXiv:1311.1904},
year = {2014}
}
Comments
Proofs simplified, a missing case supplied, and an important reference added