{ "id": "2409.11961", "version": "v1", "published": "2024-09-18T13:12:13.000Z", "updated": "2024-09-18T13:12:13.000Z", "title": "On four-dimensional Dehn twists and Milnor fibrations", "authors": [ "Hokuto Konno", "Jianfeng Lin", "Anubhav Mukherjee", "Juan Muñoz-Echániz" ], "comment": "72 pages. Comments are welcome!", "categories": [ "math.GT", "math.AG", "math.DG", "math.SG" ], "abstract": "We study the monodromy diffeomorphism of Milnor fibrations of isolated complex surface singularities, by computing the family Seiberg--Witten invariant of Seifert-fibered Dehn twists using recent advances in monopole Floer homology. More precisely, we establish infinite order non-triviality results for boundary Dehn twists on indefinite symplectic fillings of links of minimally elliptic surface singularities. Using this, we exhibit a wide variety of new phenomena in dimension four: (1) smoothings of isolated complex surface singularities whose Milnor fibration has monodromy with infinite order as a diffeomorphism but with finite order as a homeomorphism, (2) robust Torelli symplectomorphisms that do not factor as products of Dehn--Seidel twists, (3) compactly supported exotic diffeomorphisms of exotic $\\mathbb{R}^4$'s and contractible manifolds.", "revisions": [ { "version": "v1", "updated": "2024-09-18T13:12:13.000Z" } ], "analyses": { "subjects": [ "57K41", "57R58" ], "keywords": [ "milnor fibration", "four-dimensional dehn twists", "isolated complex surface singularities", "establish infinite order non-triviality results", "robust torelli symplectomorphisms" ], "note": { "typesetting": "TeX", "pages": 72, "language": "en", "license": "arXiv", "status": "editable" } } }