{"title":"On the lower bounds of the $L^2$-norm of the Hermitian scalar curvature","authors":"Julien Keller, Mehdi Lejmi","doi":"10.4310/jsg.2020.v18.n2.a5","DOIUrl":"https://doi.org/10.4310/jsg.2020.v18.n2.a5","url":null,"abstract":"On a pre-quantized symplectic manifold, we show that the symplectic Futaki invariant, which is an obstruction to the existence of constant Hermitian scalar curvature almost-K\"ahler metrics, is actually an asymptotic invariant. This allows us to deduce a lower bound for the L^2-norm of the Hermitian scalar curvature as obtained by S. Donaldson cite{Don} in the K\"ahler case.","PeriodicalId":50029,"journal":{"name":"Journal of Symplectic Geometry","volume":"1 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2017-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72857861","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Existence of noncontractible periodic orbits of Hamiltonian systems separating two Lagrangian tori on $T^{*} mathbb{T}^n$ with application to nonconvex systems","authors":"Jinxin Xue","doi":"10.4310/JSG.2017.V15.N3.A10","DOIUrl":"https://doi.org/10.4310/JSG.2017.V15.N3.A10","url":null,"abstract":"In this paper, we show the existence of non-contractible periodic orbits in Hamiltonian systems defined on T ∗Tn separating two Lagrangian tori under a certain cone assumption. Our result gives a positive answer to a question of Polterovich in [P]. As an application, we find periodic orbits in almost all the homotopy classes on a dense set of energy levels in Lorentzian type mechanical Hamiltonian systems defined on T ∗T2. This solves a problem of Arnold in [A].","PeriodicalId":50029,"journal":{"name":"Journal of Symplectic Geometry","volume":"44 1","pages":"905-936"},"PeriodicalIF":0.7,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79362673","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Lagrangian submanifolds at infinity and their parametrization","authors":"S. Coriasco, R. Schulz","doi":"10.4310/JSG.2017.V15.N4.A1","DOIUrl":"https://doi.org/10.4310/JSG.2017.V15.N4.A1","url":null,"abstract":"In this paper, we study a class of Lagrangian submanifolds which may be viewed as intersecting at infinity. They are objects natu-rally associated with a class of tempered oscillatory integrals. In this context, we prove the adapted versions of the classical the-orems, such as parametrization results, as well as equivalence of phase functions.","PeriodicalId":50029,"journal":{"name":"Journal of Symplectic Geometry","volume":"69 1","pages":"937-982"},"PeriodicalIF":0.7,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80347789","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"On non-contractible periodic orbits of symplectomorphisms","authors":"Marta Batoréo","doi":"10.4310/JSG.2017.V15.N3.A3","DOIUrl":"https://doi.org/10.4310/JSG.2017.V15.N3.A3","url":null,"abstract":"We prove the existence of infinitely many periodic points of symplectomorphisms isotopic to the identity if they admit at least one (non-contractible) hyperbolic periodic orbit and satisfy some condition on its flux. The obtained periodic points correspond to periodic orbits whose free homotopy classes are formed by iterations of the hyperbolic periodic orbit. Our result is proved for a certain class of closed symplectic manifolds and the main tool we use is a variation of Floer theory for non-contractible periodic orbits and symplectomorphisms, the Floer–Novikov theory. For a certain class of symplectic manifolds, the theorem generalizes the main results proved for Hamiltonian diffeomorphisms in [16] and for symplectomorphisms and contractible orbits in [2].","PeriodicalId":50029,"journal":{"name":"Journal of Symplectic Geometry","volume":"27 1","pages":"687-717"},"PeriodicalIF":0.7,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82652653","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Squared Dehn twists and deformed symplectic invariants","authors":"Kyler Siegel","doi":"10.4310/jsg.2021.v19.n5.a5","DOIUrl":"https://doi.org/10.4310/jsg.2021.v19.n5.a5","url":null,"abstract":"We establish an infinitesimal version of fragility for squared Dehn twists around even dimensional Lagrangian spheres. The precise formulation involves twisting the Fukaya category by a closed two-form or bulk deforming it by a half-dimensional cycle. As our main application, we compute the twisted and bulk deformed symplectic cohomology of the subflexible Weinstein manifolds constructed in cite{murphysiegel}.","PeriodicalId":50029,"journal":{"name":"Journal of Symplectic Geometry","volume":"17 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2016-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85196083","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Picard groups of $b$-symplectic manifolds","authors":"J. Villatoro","doi":"10.4310/JSG.2021.v19.n3.a6","DOIUrl":"https://doi.org/10.4310/JSG.2021.v19.n3.a6","url":null,"abstract":"We compute the Picard group of a stable b-symplectic manifold $M$ by introducing a collection of discrete invariants $mathfrak{Gr}$ which classify $M$ up to Morita equivalence.","PeriodicalId":50029,"journal":{"name":"Journal of Symplectic Geometry","volume":"26 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2016-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73735161","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Contact categories of disks","authors":"K. Honda, Yin Tian","doi":"10.4310/jsg.2022.v20.n3.a3","DOIUrl":"https://doi.org/10.4310/jsg.2022.v20.n3.a3","url":null,"abstract":"In the first part of the paper we associate a pre-additive category $mathcal{C}(Sigma)$ to a closed oriented surface $Sigma$, called the {em contact category} and constructed from contact structures on $Sigmatimes[0,1]$. There are also $mathcal{C}(Sigma,F)$, where $Sigma$ is a compact oriented surface with boundary and $Fsubset partialSigma$ is a finite oriented set of points which bounds a submanifold of $partialSigma$, and universal covers $widetilde{mathcal{C}}(Sigma)$ and $widetilde{mathcal{C}}(Sigma,F)$ of $mathcal{C}(Sigma)$ and $mathcal{C}(Sigma,F)$. In the second part of the paper we prove that the universal cover of the contact category of a disk admits an embedding into its \"triangulated envelope.\"","PeriodicalId":50029,"journal":{"name":"Journal of Symplectic Geometry","volume":"1 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2016-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78867508","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Symplectically replacing plumbings with Euler characteristic $2 : 4$‑manifolds","authors":"Jonathan Simone","doi":"10.4310/jsg.2020.v18.n5.a4","DOIUrl":"https://doi.org/10.4310/jsg.2020.v18.n5.a4","url":null,"abstract":"We introduce new symplectic cut-and-paste operations that generalize the rational blowdown. In particular, we will define $k$-replaceable plumbings to be those that, heuristically, can be symplectically replaced by Euler characteristic $k$ 4-manifolds. We will then classify 2-replaceable linear plumbings, construct 2-replaceable plumbing trees, and use one such tree to construct a symplectic exotic $mathbb{C}P^2#6overline{mathbb{C}P^2}$.","PeriodicalId":50029,"journal":{"name":"Journal of Symplectic Geometry","volume":"1654 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2016-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86392717","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Differential forms, Fukaya $A_infty$ algebras, and Gromov–Witten axioms","authors":"Jake Solomon, Sara B. Tukachinsky","doi":"10.4310/JSG.2022.v20.n4.a5","DOIUrl":"https://doi.org/10.4310/JSG.2022.v20.n4.a5","url":null,"abstract":"Consider the differential forms $A^*(L)$ on a Lagrangian submanifold $L subset X$. Following ideas of Fukaya-Oh-Ohta-Ono, we construct a family of cyclic unital curved $A_infty$ structures on $A^*(L),$ parameterized by the cohomology of $X$ relative to $L.$ The family of $A_infty$ structures satisfies properties analogous to the axioms of Gromov-Witten theory. Our construction is canonical up to $A_infty$ pseudoisotopy. We work in the situation that moduli spaces are regular and boundary evaluation maps are submersions, and thus we do not use the theory of the virtual fundamental class.","PeriodicalId":50029,"journal":{"name":"Journal of Symplectic Geometry","volume":"50 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2016-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91357138","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The diffeomorphism type of symplectic fillings","authors":"Kilian Barth, H. Geiges, Kai Zehmisch","doi":"10.4310/jsg.2019.v17.n4.a1","DOIUrl":"https://doi.org/10.4310/jsg.2019.v17.n4.a1","url":null,"abstract":"We show that simply connected contact manifolds that are subcritically Stein fillable have a unique symplectically aspherical filling up to diffeomorphism. Various extensions to manifolds with non-trivial fundamental group are discussed. The proof rests on homological restrictions on symplectic fillings derived from a degree-theoretic analysis of the evaluation map on a suitable moduli space of holomorphic spheres. Applications of this homological result include a proof that compositions of right-handed Dehn twists on Liouville domains are of infinite order in the symplectomorphism group. We also derive uniqueness results for subcritical Stein fillings up to homotopy equivalence and, under some topological assumptions on the contact manifold, up to diffeomorphism or symplectomorphism.","PeriodicalId":50029,"journal":{"name":"Journal of Symplectic Geometry","volume":"3 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2016-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87227664","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}