{"title":"The equivalence between Feynman transform and Verdier duality","authors":"Hao Yu","doi":"10.1007/s40062-021-00286-4","DOIUrl":"10.1007/s40062-021-00286-4","url":null,"abstract":"<div><p>The equivalence between dg duality and Verdier duality has been established for cyclic operads earlier. We propose a generalization of this correspondence from cyclic operads and dg duality to twisted modular operads and the Feynman transform. Specifically, for each twisted modular operad <span>(mathcal {P})</span> (taking values in dg-vector spaces over a field <i>k</i> of characteristic 0), there is a certain sheaf <span>(mathcal {F})</span> associated with it on the moduli space of stable metric graphs such that the Verdier dual sheaf <span>(Dmathcal {F})</span> is associated with the Feynman transform <span>(Fmathcal {P})</span> of <span>(mathcal {P})</span>. In the course of the proof, we also prove a relation between cyclic operads and modular operads originally proposed in the pioneering work of Getzler and Kapranov; however, to the best knowledge of the author, no proof has appeared. This geometric interpretation in operad theory is of fundamental importance. We believe this result will illuminate many aspects of the theory of modular operads and find many applications in the future. We illustrate an application of this result, giving another proof on the homotopy properties of the Feynman transform, which is quite intuitive and simpler than the original proof.</p></div>","PeriodicalId":49034,"journal":{"name":"Journal of Homotopy and Related Structures","volume":"16 3","pages":"427 - 449"},"PeriodicalIF":0.5,"publicationDate":"2021-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s40062-021-00286-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4893099","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"On the K(1)-local homotopy of (mathrm {tmf}wedge mathrm {tmf})","authors":"Dominic Leon Culver, Paul VanKoughnett","doi":"10.1007/s40062-021-00283-7","DOIUrl":"10.1007/s40062-021-00283-7","url":null,"abstract":"<div><p>As a step towards understanding the <span>(mathrm {tmf})</span>-based Adams spectral sequence, we compute the <i>K</i>(1)-local homotopy of <span>(mathrm {tmf}wedge mathrm {tmf})</span>, using a small presentation of <span>(L_{K(1)}mathrm {tmf})</span> due to Hopkins. We also describe the <i>K</i>(1)-local <span>(mathrm {tmf})</span>-based Adams spectral sequence.</p></div>","PeriodicalId":49034,"journal":{"name":"Journal of Homotopy and Related Structures","volume":"16 3","pages":"367 - 426"},"PeriodicalIF":0.5,"publicationDate":"2021-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s40062-021-00283-7","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4792783","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"2-Segal objects and algebras in spans","authors":"Walker H. Stern","doi":"10.1007/s40062-021-00282-8","DOIUrl":"https://doi.org/10.1007/s40062-021-00282-8","url":null,"abstract":"<p>We define a category parameterizing Calabi–Yau algebra objects in an infinity category of spans. Using this category, we prove that there are equivalences of infinity categories relating, firstly: 2-Segal simplicial objects in C to algebra objects in Span(C); and secondly: 2-Segal cyclic objects in C to Calabi–Yau algebra objects in Span(C).</p>","PeriodicalId":49034,"journal":{"name":"Journal of Homotopy and Related Structures","volume":"16 2","pages":"297 - 361"},"PeriodicalIF":0.5,"publicationDate":"2021-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s40062-021-00282-8","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4694359","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Torsion in the magnitude homology of graphs","authors":"Radmila Sazdanovic, Victor Summers","doi":"10.1007/s40062-021-00281-9","DOIUrl":"https://doi.org/10.1007/s40062-021-00281-9","url":null,"abstract":"<p>Magnitude homology is a bigraded homology theory for finite graphs defined by Hepworth and Willerton, categorifying the power series invariant known as magnitude which was introduced by Leinster. We analyze the structure and implications of torsion in magnitude homology. We show that any finitely generated abelian group may appear as a subgroup of the magnitude homology of a graph, and, in particular, that torsion of a given prime order can appear in the magnitude homology of a graph and that there are infinitely many such graphs. Finally, we provide complete computations of magnitude homology of a class of outerplanar graphs and focus on the ranks of the groups along the main diagonal of magnitude homology.</p>","PeriodicalId":49034,"journal":{"name":"Journal of Homotopy and Related Structures","volume":"16 2","pages":"275 - 296"},"PeriodicalIF":0.5,"publicationDate":"2021-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s40062-021-00281-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4620860","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Derived categories of NDG categories","authors":"Jun-ichi Miyachi, Hiroshi Nagase","doi":"10.1007/s40062-021-00279-3","DOIUrl":"https://doi.org/10.1007/s40062-021-00279-3","url":null,"abstract":"<p>In this paper we study N-differential graded categories and their derived categories. First, we introduce modules over an N-differential graded category. Then we show that they form a Frobenius category and that its homotopy category is triangulated. Second, we study the properties of its derived category and give triangle equivalences of Morita type between derived categories of N-differential graded categories. Finally, we show that this derived category is triangle equivalent to the derived category of some ordinary differential graded category.</p>","PeriodicalId":49034,"journal":{"name":"Journal of Homotopy and Related Structures","volume":"16 2","pages":"191 - 224"},"PeriodicalIF":0.5,"publicationDate":"2021-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s40062-021-00279-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5182032","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"On the relative K-group in the ETNC, Part II","authors":"Oliver Braunling","doi":"10.1007/s40062-020-00267-z","DOIUrl":"https://doi.org/10.1007/s40062-020-00267-z","url":null,"abstract":"<p>In a previous paper we showed that, under some assumptions, the relative <i>K</i>-group in the Burns–Flach formulation of the equivariant Tamagawa number conjecture (ETNC) is canonically isomorphic to a <i>K</i>-group of locally compact equivariant modules. Our approach as well as the standard one both involve presentations: One due to Bass–Swan, applied to categories of finitely generated projective modules; and one due to Nenashev, applied to our topological modules without finite generation assumptions. In this paper we provide an explicit isomorphism.</p>","PeriodicalId":49034,"journal":{"name":"Journal of Homotopy and Related Structures","volume":"15 3-4","pages":"597 - 624"},"PeriodicalIF":0.5,"publicationDate":"2020-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s40062-020-00267-z","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4269379","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Homotopy Gerstenhaber algebras are strongly homotopy commutative","authors":"Matthias Franz","doi":"10.1007/s40062-020-00268-y","DOIUrl":"https://doi.org/10.1007/s40062-020-00268-y","url":null,"abstract":"<p>We show that any homotopy Gerstenhaber algebra is naturally a strongly homotopy commutative (shc) algebra in the sense of Stasheff–Halperin with a homotopy associative structure map. In the presence of certain additional operations corresponding to a <span>(mathbin {cup _1})</span>-product on the bar construction, the structure map becomes homotopy commutative, so that one obtains an shc algebra in the sense of Munkholm.</p>","PeriodicalId":49034,"journal":{"name":"Journal of Homotopy and Related Structures","volume":"15 3-4","pages":"557 - 595"},"PeriodicalIF":0.5,"publicationDate":"2020-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s40062-020-00268-y","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4051819","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Homotopic distance between functors","authors":"E. Macías-Virgós, D. Mosquera-Lois","doi":"10.1007/s40062-020-00269-x","DOIUrl":"https://doi.org/10.1007/s40062-020-00269-x","url":null,"abstract":"<p>We introduce a notion of <i>categorical homotopic distance between functors</i> by adapting the notion of homotopic distance in topological spaces, recently defined by the authors, to the context of small categories. Moreover, this notion generalizes the work on categorical LS-category of small categories by Tanaka.</p>","PeriodicalId":49034,"journal":{"name":"Journal of Homotopy and Related Structures","volume":"15 3-4","pages":"537 - 555"},"PeriodicalIF":0.5,"publicationDate":"2020-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s40062-020-00269-x","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4557847","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Note on Toda brackets","authors":"Samik Basu, David Blanc, Debasis Sen","doi":"10.1007/s40062-020-00264-2","DOIUrl":"https://doi.org/10.1007/s40062-020-00264-2","url":null,"abstract":"<p>We provide a general definition of Toda brackets in a pointed model category, show how they serve as obstructions to rectification, and explain their relation to the classical stable operations.</p>","PeriodicalId":49034,"journal":{"name":"Journal of Homotopy and Related Structures","volume":"15 3-4","pages":"495 - 510"},"PeriodicalIF":0.5,"publicationDate":"2020-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s40062-020-00264-2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5074731","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Cyclic homology for bornological coarse spaces","authors":"Luigi Caputi","doi":"10.1007/s40062-020-00263-3","DOIUrl":"https://doi.org/10.1007/s40062-020-00263-3","url":null,"abstract":"<p>The goal of the paper is to define Hochschild and cyclic homology for bornological coarse spaces, i.e., lax symmetric monoidal functors <span>({{,mathrm{mathcal {X}HH},}}_{}^G)</span> and <span>({{,mathrm{mathcal {X}HC},}}_{}^G)</span> from the category <span>(Gmathbf {BornCoarse})</span> of equivariant bornological coarse spaces to the cocomplete stable <span>(infty )</span>-category <span>(mathbf {Ch}_infty )</span> of chain complexes reminiscent of the classical Hochschild and cyclic homology. We investigate relations to coarse algebraic <i>K</i>-theory <span>(mathcal {X}K^G_{})</span> and to coarse ordinary homology?<span>({{,mathrm{mathcal {X}H},}}^G)</span> by constructing a trace-like natural transformation <span>(mathcal {X}K_{}^Grightarrow {{,mathrm{mathcal {X}H},}}^G)</span> that factors through coarse Hochschild (and cyclic) homology. We further compare the forget-control map for <span>({{,mathrm{mathcal {X}HH},}}_{}^G)</span> with the associated generalized assembly map.</p>","PeriodicalId":49034,"journal":{"name":"Journal of Homotopy and Related Structures","volume":"15 3-4","pages":"463 - 493"},"PeriodicalIF":0.5,"publicationDate":"2020-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s40062-020-00263-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4932755","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}