{ "id": "2104.01419", "version": "v1", "published": "2021-04-03T14:35:13.000Z", "updated": "2021-04-03T14:35:13.000Z", "title": "Small Lefschetz Fibrations on Simply-Connected $4$-Manifolds", "authors": [ "Tulin Altunoz" ], "comment": "20 pages, 7 figures", "categories": [ "math.GT" ], "abstract": "We consider simply-connected $4$-manifolds admitting Lefschetz fibrations over the $2$-sphere. We explicitly construct Lefschetz fibrations of genus $3$ and $4$ on simply-connected $4$-manifolds which are exotic symplectic $4$-manifolds in the homeomorphism classes of $\\mathbb{C} P^{2}\\#7\\overline{\\mathbb{C} P^{2}}$ and $\\mathbb{C} P^{2}\\#8\\overline{\\mathbb{C} P^{2}}$, respectively. From these, we provide upper bounds for the minimal number of singular fibers of such fibrations. In addition, we prove that this number is equal to $14$ for $g=2$. When such fibrations are hyperelliptic, we prove that it is $18$ for $g=3$. Moreover, we discuss the number for higher genera.", "revisions": [ { "version": "v1", "updated": "2021-04-03T14:35:13.000Z" } ], "analyses": { "keywords": [ "small lefschetz fibrations", "manifolds admitting lefschetz fibrations", "explicitly construct lefschetz fibrations", "singular fibers", "exotic symplectic" ], "note": { "typesetting": "TeX", "pages": 20, "language": "en", "license": "arXiv", "status": "editable" } } }