{"title":"Linear isoperimetric inequality for homogeneous Hadamard manifolds","authors":"Hjalti Isleifsson","doi":"10.1142/s1793525323500334","DOIUrl":"https://doi.org/10.1142/s1793525323500334","url":null,"abstract":"It is well known that simply connected symmetric spaces of non-positive sectional curvature admit a linear isoperimetric filling inequality for cycles of dimension greater than or equal to the rank of the space. In this note we extend that result to homogeneous Hadamard manifolds.","PeriodicalId":49151,"journal":{"name":"Journal of Topology and Analysis","volume":"16 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2022-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79865581","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}
D. Fernández-Ternero, E. Macías-Virgós, D. Mosquera-Lois, J. A. Vilches
{"title":"Morse–Bott theory on posets and a homological Lusternik–Schnirelmann theorem","authors":"D. Fernández-Ternero, E. Macías-Virgós, D. Mosquera-Lois, J. A. Vilches","doi":"10.1142/s1793525321500709","DOIUrl":"https://doi.org/10.1142/s1793525321500709","url":null,"abstract":"We develop Morse–Bott theory on posets, generalizing both discrete Morse–Bott theory for regular complexes and Morse theory on posets. Moreover, we prove a Lusternik–Schnirelmann theorem for general matchings on posets, in particular, for Morse–Bott functions.","PeriodicalId":49151,"journal":{"name":"Journal of Topology and Analysis","volume":"26 47","pages":""},"PeriodicalIF":0.8,"publicationDate":"2021-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138495689","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":"Macroscopic scalar curvature and codimension 2 width","authors":"H. Alpert, Alexey Balitskiy, L. Guth","doi":"10.1142/S1793525323500024","DOIUrl":"https://doi.org/10.1142/S1793525323500024","url":null,"abstract":"We show that a complete $3$-dimensional Riemannian manifold $M$ with finitely generated first homology has macroscopic dimension $1$ if it satisfies the following\"macroscopic curvature\"assumptions: every ball of radius $10$ in $M$ has volume at most $4$, and every loop in every ball of radius $1$ in $M$ is null-homologous in the concentric ball of radius $2$.","PeriodicalId":49151,"journal":{"name":"Journal of Topology and Analysis","volume":"42 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2021-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74686550","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":"Fukaya A∞-structures associated to Lefschetz fibrations. V","authors":"Paul Seidel","doi":"10.1142/s1793525321500588","DOIUrl":"https://doi.org/10.1142/s1793525321500588","url":null,"abstract":"We (re)consider how the Fukaya category of a Lefschetz fibration is related to that of the fiber. The distinguishing feature of the approach here is a more direct identification of the bimodule homomorphism involved.","PeriodicalId":49151,"journal":{"name":"Journal of Topology and Analysis","volume":"26 50","pages":""},"PeriodicalIF":0.8,"publicationDate":"2021-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138495688","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":"Rigidity of mean convex subsets in non-negatively curved RCD spaces and stability of mean curvature bounds","authors":"C. Ketterer","doi":"10.1142/s1793525323500358","DOIUrl":"https://doi.org/10.1142/s1793525323500358","url":null,"abstract":"We prove splitting theorems for mean convex open subsets in RCD (Riemannian curvature-dimension) spaces that extend results by Kasue, Croke and Kleiner for Riemannian manifolds with boundary to a non-smooth setting. A corollary is for instance Frankel's theorem. Then, we prove that our notion of mean curvature bounded from below for the boundary of an open subset is stable w.r.t. to uniform convergence of the corresponding boundary distance function. We apply this to prove almost rigidity theorems for uniform domains whose boundary has a lower mean curvature bound.","PeriodicalId":49151,"journal":{"name":"Journal of Topology and Analysis","volume":"9 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2021-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72804073","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":"Commutativity of the Haagerup tensor product and base change for operator modules","authors":"Tyrone Crisp","doi":"10.1142/s179352532150062x","DOIUrl":"https://doi.org/10.1142/s179352532150062x","url":null,"abstract":"By computing the completely bounded norm of the flip map on the Haagerup tensor product [Formula: see text] associated to a pair of continuous mappings of locally compact Hausdorff spaces [Formula: see text], we establish a simple characterization of the Beck-Chevalley condition for base change of operator modules over commutative [Formula: see text]-algebras, and a descent theorem for continuous fields of Hilbert spaces.","PeriodicalId":49151,"journal":{"name":"Journal of Topology and Analysis","volume":"276 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2021-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79155764","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 geodesically reversible Finsler manifolds","authors":"Yong Fang","doi":"10.1142/s1793525321500576","DOIUrl":"https://doi.org/10.1142/s1793525321500576","url":null,"abstract":"A Finsler manifold is said to be geodesically reversible if the reversed curve of any geodesic remains a geometrical geodesic. Well-known examples of geodesically reversible Finsler metrics are Randers metrics with closed [Formula: see text]-forms. Another family of well-known examples are projectively flat Finsler metrics on the [Formula: see text]-sphere that have constant positive curvature. In this paper, we prove some geometrical and dynamical characterizations of geodesically reversible Finsler metrics, and we prove several rigidity results about a family of the so-called Randers-type Finsler metrics. One of our results is as follows: let [Formula: see text] be a Riemannian–Finsler metric on a closed surface [Formula: see text], and [Formula: see text] be a small antisymmetric potential on [Formula: see text] that is a natural generalization of [Formula: see text]-form (see Sec. 1). If the Randers-type Finsler metric [Formula: see text] is geodesically reversible, and the geodesic flow of [Formula: see text] is topologically transitive, then we prove that [Formula: see text] must be a closed [Formula: see text]-form. We also prove that this rigidity result is not true for the family of projectively flat Finsler metrics on the [Formula: see text]-sphere of constant positive curvature.","PeriodicalId":49151,"journal":{"name":"Journal of Topology and Analysis","volume":"46 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2021-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73529913","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":"Periodic solutions of Hilbert’s fourth problem","authors":"J. C. Álvarez Paiva, J. Barbosa Gomes","doi":"10.1142/s1793525321500552","DOIUrl":"https://doi.org/10.1142/s1793525321500552","url":null,"abstract":"It is shown that a possibly irreversible [Formula: see text] Finsler metric on the torus, or on any other compact Euclidean space form, whose geodesics are straight lines is the sum of a flat metric and a closed [Formula: see text]-form. This is used to prove that if [Formula: see text] is a compact Riemannian symmetric space of rank greater than one and [Formula: see text] is a reversible [Formula: see text] Finsler metric on [Formula: see text] whose unparametrized geodesics coincide with those of [Formula: see text], then [Formula: see text] is a Finsler symmetric space.","PeriodicalId":49151,"journal":{"name":"Journal of Topology and Analysis","volume":"90 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2021-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80477408","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":"Homological Eigenvalues of graph p-Laplacians","authors":"Dong Zhang","doi":"10.1142/s1793525323500346","DOIUrl":"https://doi.org/10.1142/s1793525323500346","url":null,"abstract":"Inspired by persistent homology in topological data analysis, we introduce the homological eigenvalues of the graph $p$-Laplacian $Delta_p$, which allows us to analyse and classify non-variational eigenvalues. We show the stability of homological eigenvalues, and we prove that for any homological eigenvalue $lambda(Delta_p)$, the function $pmapsto p(2lambda(Delta_p))^{frac1p}$ is locally increasing, while the function $pmapsto 2^{-p}lambda(Delta_p)$ is locally decreasing. As a special class of homological eigenvalues, the min-max eigenvalues $lambda_1(Delta_p)$, $cdots$, $lambda_k(Delta_p)$, $cdots$, are locally Lipschitz continuous with respect to $pin[1,+infty)$. We also establish the monotonicity of $p(2lambda_k(Delta_p))^{frac1p}$ and $2^{-p}lambda_k(Delta_p)$ with respect to $pin[1,+infty)$. These results systematically establish a refined analysis of $Delta_p$-eigenvalues for varying $p$, which lead to several applications, including: (1) settle an open problem by Amghibech on the monotonicity of some function involving eigenvalues of $p$-Laplacian with respect to $p$; (2) resolve a question asking whether the third eigenvalue of graph $p$-Laplacian is of min-max form; (3) refine the higher order Cheeger inequalities for graph $p$-Laplacians by Tudisco and Hein, and extend the multi-way Cheeger inequality by Lee, Oveis Gharan and Trevisan to the $p$-Laplacian case. Furthermore, for the 1-Laplacian case, we characterize the homological eigenvalues and min-max eigenvalues from the perspective of topological combinatorics, where our idea is similar to the authors' work on discrete Morse theory.","PeriodicalId":49151,"journal":{"name":"Journal of Topology and Analysis","volume":"58 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2021-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91295862","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":"Complete 3-dimensional λ-translators in the Euclidean space ℝ4","authors":"Zhi Li, G. Wei, Gangyi Chen","doi":"10.1142/s1793525321500540","DOIUrl":"https://doi.org/10.1142/s1793525321500540","url":null,"abstract":"In this paper, we obtain the classification theorems for 3-dimensional complete [Formula: see text]-translators [Formula: see text] with constant squared norm [Formula: see text] of the second fundamental form and constant [Formula: see text] in the Euclidean space [Formula: see text].","PeriodicalId":49151,"journal":{"name":"Journal of Topology and Analysis","volume":"39 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2021-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80518363","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}