{ "id": "1907.03330", "version": "v1", "published": "2019-07-07T18:32:12.000Z", "updated": "2019-07-07T18:32:12.000Z", "title": "Counting rational curves on K3 surfaces with finite group actions", "authors": [ "Sailun Zhan" ], "comment": "36 pages. Comments are very welcome", "categories": [ "math.AG" ], "abstract": "G\\\"ottsche gave a formula for the dimension of the cohomology of Hilbert schemes of points on a smooth projective surface $S$. When $S$ admits an action by a finite group $G$, we describe the action of $G$ on the cohomology spaces. In the case that $S$ is a K3 surface, each element of $G$ gives a trace on $\\sum_{n=0}\\sum_{i=0}(-1)^{i}H^{i}(S^{[n]},\\mathbb{C})q^{n}$. When $G$ acts faithfully and symplectically on $S$, the resulting generating function is of the form $q/f(q)$, where $f(q)$ is a cusp form. We relate the cohomology of Hilbert schemes of points to the cohomology of the compactified Jacobian of the tautological family of curves over an integral linear system on a K3 surface as $G$-representations. We give a sufficient condition for a $G$-orbit of curves with nodal singularities not to contribute to the representation.", "revisions": [ { "version": "v1", "updated": "2019-07-07T18:32:12.000Z" } ], "analyses": { "keywords": [ "k3 surface", "finite group actions", "counting rational curves", "cohomology", "hilbert schemes" ], "note": { "typesetting": "TeX", "pages": 36, "language": "en", "license": "arXiv", "status": "editable" } } }