The polarized degree of irrationality of $K3$ surfaces

Autor: Moretti, Federico
Rok vydání: 2023
Předmět:
Druh dokumentu: Working Paper
Popis: Given a polarized variety $(X,L)$ we use an elementary observation to produce projections of low degree $ X\subset \mathbb{P}(H^0(L^\vee)) \dashrightarrow \mathbb P ^r $ via vector bundles. For surfaces this observation can be used to show that maps of the degree at most $d$ move in families. In the case of polarized $K3$ surfaces we study projections of the lowest possible degree up to genus $6$ and we give a new upper bound for higher genera. As a different application of our construction we exhibit new rational maps of low degree for some hyper-K\"ahler varieties, abelian varieties and Gushel-Mukai threefolds.
Comment: 10 pages, comments are welcome! Notice that the previous versions of this paper contained also a lower bound but the proof contained a mistake
Databáze: arXiv