eprintid: 10205710 rev_number: 8 eprint_status: archive userid: 699 dir: disk0/10/20/57/10 datestamp: 2025-03-07 13:03:00 lastmod: 2025-03-07 13:05:12 status_changed: 2025-03-07 13:03:00 type: article metadata_visibility: show sword_depositor: 699 creators_name: Karpukhin, Mikhail creators_name: Nahon, Mickaël creators_name: Polterovich, Iosif creators_name: Stern, Daniel title: Stability of isoperimetric inequalities for Laplace eigenvalues on surfaces ispublished: pub divisions: UCL divisions: B04 divisions: C06 divisions: F59 note: This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions. abstract: We prove stability estimates for the isoperimetric inequalities for the first and the second nonzero Laplace eigenvalues on surfaces, both globally and in a fixed conformal class. We employ the notion of eigenvalues of measures and show that if a normalized eigenvalue is close to its maximal value, the corresponding measure must be close in the Sobolev space W−1,2 to the set of maximizing measures. In particular, this implies a qualitative stability result: metrics almost maximizing the normalized eigenvalue must be W−1,2–close to a maximal metric. Following this approach, we prove sharp quantitative stability of the celebrated Hersch’s inequality for the first eigenvalue on the sphere, as well as of its counterpart for the second eigenvalue. Similar results are also obtained for the precise isoperimetric eigenvalue inequalities on the projective plane, torus, and Klein bottle. The square of the W−1,2 distance to a maximizing measure in these stability estimates is controlled by the difference between the normalized eigenvalue and its maximal value, indicating that the maxima are in a sense nondegenerate. We construct examples showing that the power of the distance can not be improved, and that the choice of the Sobolev space W−1,2 is optimal. date: 2025-02 date_type: published publisher: International Press of Boston official_url: https://doi.org/10.4310/jdg/1738163208 oa_status: green full_text_type: other language: eng primo: open primo_central: open_green verified: verified_manual elements_id: 2363801 doi: 10.4310/jdg/1738163208 lyricists_name: Karpukhin, Mikhail lyricists_id: MKARP96 actors_name: Karpukhin, Mikhail actors_id: MKARP96 actors_role: owner full_text_status: public publication: Journal of Differential Geometry volume: 129 number: 2 pagerange: 415-490 issn: 0022-040X citation: Karpukhin, Mikhail; Nahon, Mickaël; Polterovich, Iosif; Stern, Daniel; (2025) Stability of isoperimetric inequalities for Laplace eigenvalues on surfaces. Journal of Differential Geometry , 129 (2) pp. 415-490. 10.4310/jdg/1738163208 <https://doi.org/10.4310/jdg%2F1738163208>. Green open access document_url: https://discovery.ucl.ac.uk/id/eprint/10205710/1/stability_submit_v2.pdf