Obstructions to reversing Lagrangian surgery in Lagrangian fillingsShow others and affiliations
2024 (English)In: The Journal of Symplectic Geometry, ISSN 1527-5256, E-ISSN 1540-2347, Vol. 22, no 3, p. 599-672Article in journal (Refereed) Published
Abstract [en]
Given an immersed, Maslov-0, exact Lagrangian filling of a Legendrian knot, if the filling has a vanishing index and action double point, then through Lagrangian surgery it is possible to obtain a new immersed, Maslov-0, exact Lagrangian filling with one less double point and with genus increased by one. We show that it is not always possible to reverse the Lagrangian surgery: not every immersed, Maslov-0, exact Lagrangian filling with genus g≥1 and p double points can be obtained from such a Lagrangian surgery on a filling of genus g−1 with p+1 double points. To show this, we establish the connection between the existence of an immersed, Maslov-0, exact Lagrangian filling of a Legendrian Λ that has p double points with action 0 and the existence of an embedded, Maslov-0, exact Lagrangian cobordism from p copies of a Hopf link to Λ. We then prove that a count of augmentations provides an obstruction to the existence of embedded, Maslov-0, exact Lagrangian cobordisms between Legendrian links.
Place, publisher, year, edition, pages
International Press , 2024. Vol. 22, no 3, p. 599-672
National Category
Mathematical sciences
Identifiers
URN: urn:nbn:se:hig:diva-46601DOI: 10.4310/jsg.241001214710ISI: 001492750700004Scopus ID: 2-s2.0-85218731719OAI: oai:DiVA.org:hig-46601DiVA, id: diva2:1943202
2025-03-102025-03-102025-10-02Bibliographically approved