{"title":"A new proof of the Bondal–Orlov reconstruction using Matsui spectra","authors":"Daigo Ito, Hiroki Matsui","doi":"10.1112/blms.70079","DOIUrl":null,"url":null,"abstract":"<p>In 2005, Balmer defined the ringed space <span></span><math>\n <semantics>\n <mrow>\n <msub>\n <mo>Spec</mo>\n <mo>⊗</mo>\n </msub>\n <mi>T</mi>\n </mrow>\n <annotation>$\\operatorname{Spec}_\\otimes \\mathcal {T}$</annotation>\n </semantics></math> for a given tensor triangulated category, while in 2023, the second author introduced the ringed space <span></span><math>\n <semantics>\n <mrow>\n <msub>\n <mo>Spec</mo>\n <mi>▵</mi>\n </msub>\n <mi>T</mi>\n </mrow>\n <annotation>$\\operatorname{Spec}_\\vartriangle \\mathcal {T}$</annotation>\n </semantics></math> for a given triangulated category. In the algebro-geometric context, these spectra provided several reconstruction theorems using derived categories. In this paper, we prove that <span></span><math>\n <semantics>\n <mrow>\n <msub>\n <mo>Spec</mo>\n <msubsup>\n <mo>⊗</mo>\n <mi>X</mi>\n <mi>L</mi>\n </msubsup>\n </msub>\n <mo>Perf</mo>\n <mi>X</mi>\n </mrow>\n <annotation>$\\operatorname{Spec}_{\\otimes _X^\\mathbb {L}} \\operatorname{Perf} X$</annotation>\n </semantics></math> is an open ringed subspace of <span></span><math>\n <semantics>\n <mrow>\n <msub>\n <mo>Spec</mo>\n <mi>▵</mi>\n </msub>\n <mo>Perf</mo>\n <mi>X</mi>\n </mrow>\n <annotation>$\\operatorname{Spec}_\\vartriangle \\operatorname{Perf} X$</annotation>\n </semantics></math> for a quasi-projective variety <span></span><math>\n <semantics>\n <mi>X</mi>\n <annotation>$X$</annotation>\n </semantics></math>. As an application, we provide a new proof of the Bondal–Orlov and Ballard reconstruction theorems in terms of these spectra. Recently, the first author introduced the Fourier–Mukai locus <span></span><math>\n <semantics>\n <mrow>\n <msup>\n <mo>Spec</mo>\n <mi>FM</mi>\n </msup>\n <mo>Perf</mo>\n <mi>X</mi>\n </mrow>\n <annotation>$\\operatorname{Spec}^\\mathsf {FM} \\operatorname{Perf} X$</annotation>\n </semantics></math> for a smooth projective variety <span></span><math>\n <semantics>\n <mi>X</mi>\n <annotation>$X$</annotation>\n </semantics></math>, which is constructed by gluing Fourier–Mukai partners of <span></span><math>\n <semantics>\n <mi>X</mi>\n <annotation>$X$</annotation>\n </semantics></math> inside <span></span><math>\n <semantics>\n <mrow>\n <msub>\n <mo>Spec</mo>\n <mi>▵</mi>\n </msub>\n <mo>Perf</mo>\n <mi>X</mi>\n </mrow>\n <annotation>$\\operatorname{Spec}_\\vartriangle \\operatorname{Perf} X$</annotation>\n </semantics></math>. As another application of our main theorem, we demonstrate that <span></span><math>\n <semantics>\n <mrow>\n <msup>\n <mo>Spec</mo>\n <mi>FM</mi>\n </msup>\n <mo>Perf</mo>\n <mi>X</mi>\n </mrow>\n <annotation>$\\operatorname{Spec}^\\mathsf {FM} \\operatorname{Perf} X$</annotation>\n </semantics></math> can be viewed as an open ringed subspace of <span></span><math>\n <semantics>\n <mrow>\n <msub>\n <mo>Spec</mo>\n <mi>▵</mi>\n </msub>\n <mo>Perf</mo>\n <mi>X</mi>\n </mrow>\n <annotation>$\\operatorname{Spec}_\\vartriangle \\operatorname{Perf} X$</annotation>\n </semantics></math>. As a result, we show that all the Fourier–Mukai partners of an abelian variety <span></span><math>\n <semantics>\n <mi>X</mi>\n <annotation>$X$</annotation>\n </semantics></math> can be reconstructed by topologically identifying the Fourier–Mukai locus within <span></span><math>\n <semantics>\n <mrow>\n <msub>\n <mo>Spec</mo>\n <mi>▵</mi>\n </msub>\n <mo>Perf</mo>\n <mi>X</mi>\n </mrow>\n <annotation>$\\operatorname{Spec}_\\vartriangle \\operatorname{Perf} X$</annotation>\n </semantics></math>.</p>","PeriodicalId":55298,"journal":{"name":"Bulletin of the London Mathematical Society","volume":"57 7","pages":"2058-2076"},"PeriodicalIF":0.9000,"publicationDate":"2025-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Bulletin of the London Mathematical Society","FirstCategoryId":"100","ListUrlMain":"https://londmathsoc.onlinelibrary.wiley.com/doi/10.1112/blms.70079","RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MATHEMATICS","Score":null,"Total":0}
引用次数: 0
Abstract
In 2005, Balmer defined the ringed space for a given tensor triangulated category, while in 2023, the second author introduced the ringed space for a given triangulated category. In the algebro-geometric context, these spectra provided several reconstruction theorems using derived categories. In this paper, we prove that is an open ringed subspace of for a quasi-projective variety . As an application, we provide a new proof of the Bondal–Orlov and Ballard reconstruction theorems in terms of these spectra. Recently, the first author introduced the Fourier–Mukai locus for a smooth projective variety , which is constructed by gluing Fourier–Mukai partners of inside . As another application of our main theorem, we demonstrate that can be viewed as an open ringed subspace of . As a result, we show that all the Fourier–Mukai partners of an abelian variety can be reconstructed by topologically identifying the Fourier–Mukai locus within .