{ "id": "2204.09152", "version": "v1", "published": "2022-04-19T22:57:17.000Z", "updated": "2022-04-19T22:57:17.000Z", "title": "Feigin-Odesskii brackets, syzygies, and Cremona transformations", "authors": [ "Alexander Polishchuk" ], "comment": "10 pages", "categories": [ "math.AG" ], "abstract": "We identify Feigin-Odesskii brackets $q_{n,1}(C)$, associated with a normal elliptic curve of degree $n$, $C\\subset {\\mathbb P}^{n-1}$, with the skew-symmetric $n\\times n$ matrix of quadratic forms introduced by Fisher in arXiv:1510.04327 in connection with some minimal free resolutions related to the secant varieties of $C$. On the other hand, we show that for odd $n$, the generators of the ideal of the secant variety of $C$ of codimension $3$ give a Cremona transformation of ${\\mathbb P}^{n-1}$, generalizing the quadro-cubic Cremona transformation of ${\\mathbb P}^4$. We identify this transformation with the one considered in arXiv:alg-geom/9712022 and find explict formulas for the inverse transformation.", "revisions": [ { "version": "v1", "updated": "2022-04-19T22:57:17.000Z" } ], "analyses": { "keywords": [ "secant variety", "quadro-cubic cremona transformation", "minimal free resolutions", "normal elliptic curve", "identify feigin-odesskii brackets" ], "note": { "typesetting": "TeX", "pages": 10, "language": "en", "license": "arXiv", "status": "editable" } } }