Abdolnaser Bahlekeh, Fahimeh Sadat Fotouhi, Mohammad Amin Hamlehdari, Shokrollah Salarian
{"title":"The stable category of monomorphisms between (Gorenstein) projective modules with applications","authors":"Abdolnaser Bahlekeh, Fahimeh Sadat Fotouhi, Mohammad Amin Hamlehdari, Shokrollah Salarian","doi":"10.1515/forum-2023-0317","DOIUrl":null,"url":null,"abstract":"Let <jats:inline-formula> <jats:alternatives> <m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\"> <m:mrow> <m:mo stretchy=\"false\">(</m:mo> <m:mi>S</m:mi> <m:mo>,</m:mo> <m:mi>𝔫</m:mi> <m:mo stretchy=\"false\">)</m:mo> </m:mrow> </m:math> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"graphic/j_forum-2023-0317_eq_0072.png\"/> <jats:tex-math>{(S,{\\mathfrak{n}})}</jats:tex-math> </jats:alternatives> </jats:inline-formula> be a commutative noetherian local ring and let <jats:inline-formula> <jats:alternatives> <m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\"> <m:mrow> <m:mi>ω</m:mi> <m:mo>∈</m:mo> <m:mi>𝔫</m:mi> </m:mrow> </m:math> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"graphic/j_forum-2023-0317_eq_0207.png\"/> <jats:tex-math>{\\omega\\in{\\mathfrak{n}}}</jats:tex-math> </jats:alternatives> </jats:inline-formula> be non-zerodivisor. This paper is concerned with the two categories of monomorphisms between finitely generated (Gorenstein) projective <jats:italic>S</jats:italic>-modules, such that their cokernels are annihilated by ω. It is shown that these categories, which will be denoted by <jats:inline-formula> <jats:alternatives> <m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\"> <m:mrow> <m:mi>𝖬𝗈𝗇</m:mi> <m:mo></m:mo> <m:mrow> <m:mo stretchy=\"false\">(</m:mo> <m:mi>ω</m:mi> <m:mo>,</m:mo> <m:mi mathvariant=\"script\">𝒫</m:mi> <m:mo stretchy=\"false\">)</m:mo> </m:mrow> </m:mrow> </m:math> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"graphic/j_forum-2023-0317_eq_0342.png\"/> <jats:tex-math>{{\\mathsf{Mon}}(\\omega,\\mathcal{P})}</jats:tex-math> </jats:alternatives> </jats:inline-formula> and <jats:inline-formula> <jats:alternatives> <m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\"> <m:mrow> <m:mi>𝖬𝗈𝗇</m:mi> <m:mo></m:mo> <m:mrow> <m:mo stretchy=\"false\">(</m:mo> <m:mi>ω</m:mi> <m:mo>,</m:mo> <m:mi mathvariant=\"script\">𝒢</m:mi> <m:mo stretchy=\"false\">)</m:mo> </m:mrow> </m:mrow> </m:math> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"graphic/j_forum-2023-0317_eq_0341.png\"/> <jats:tex-math>{{\\mathsf{Mon}}(\\omega,\\mathcal{G})}</jats:tex-math> </jats:alternatives> </jats:inline-formula>, are both Frobenius categories with the same projective objects. It is also proved that the stable category <jats:inline-formula> <jats:alternatives> <m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\"> <m:mrow> <m:munder accentunder=\"true\"> <m:mi>𝖬𝗈𝗇</m:mi> <m:mo>¯</m:mo> </m:munder> <m:mo></m:mo> <m:mrow> <m:mo stretchy=\"false\">(</m:mo> <m:mi>ω</m:mi> <m:mo>,</m:mo> <m:mi mathvariant=\"script\">𝒫</m:mi> <m:mo stretchy=\"false\">)</m:mo> </m:mrow> </m:mrow> </m:math> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"graphic/j_forum-2023-0317_eq_0277.png\"/> <jats:tex-math>{\\underline{\\mathsf{Mon}}(\\omega,\\mathcal{P})}</jats:tex-math> </jats:alternatives> </jats:inline-formula> is triangle equivalent to the category of D-branes of type B, <jats:inline-formula> <jats:alternatives> <m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\"> <m:mrow> <m:mi>𝖣𝖡</m:mi> <m:mo></m:mo> <m:mrow> <m:mo stretchy=\"false\">(</m:mo> <m:mi>ω</m:mi> <m:mo stretchy=\"false\">)</m:mo> </m:mrow> </m:mrow> </m:math> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"graphic/j_forum-2023-0317_eq_0181.png\"/> <jats:tex-math>{\\mathsf{DB}(\\omega)}</jats:tex-math> </jats:alternatives> </jats:inline-formula>, which has been introduced by Kontsevich and studied by Orlov. Moreover, it will be observed that the stable categories <jats:inline-formula> <jats:alternatives> <m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\"> <m:mrow> <m:munder accentunder=\"true\"> <m:mi>𝖬𝗈𝗇</m:mi> <m:mo>¯</m:mo> </m:munder> <m:mo></m:mo> <m:mrow> <m:mo stretchy=\"false\">(</m:mo> <m:mi>ω</m:mi> <m:mo>,</m:mo> <m:mi mathvariant=\"script\">𝒫</m:mi> <m:mo stretchy=\"false\">)</m:mo> </m:mrow> </m:mrow> </m:math> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"graphic/j_forum-2023-0317_eq_0277.png\"/> <jats:tex-math>{\\underline{\\mathsf{Mon}}(\\omega,\\mathcal{P})}</jats:tex-math> </jats:alternatives> </jats:inline-formula> and <jats:inline-formula> <jats:alternatives> <m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\"> <m:mrow> <m:munder accentunder=\"true\"> <m:mi>𝖬𝗈𝗇</m:mi> <m:mo>¯</m:mo> </m:munder> <m:mo></m:mo> <m:mrow> <m:mo stretchy=\"false\">(</m:mo> <m:mi>ω</m:mi> <m:mo>,</m:mo> <m:mi mathvariant=\"script\">𝒢</m:mi> <m:mo stretchy=\"false\">)</m:mo> </m:mrow> </m:mrow> </m:math> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"graphic/j_forum-2023-0317_eq_0276.png\"/> <jats:tex-math>{\\underline{\\mathsf{Mon}}(\\omega,\\mathcal{G})}</jats:tex-math> </jats:alternatives> </jats:inline-formula> are closely related to the singularity category of the factor ring <jats:inline-formula> <jats:alternatives> <m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\"> <m:mrow> <m:mi>R</m:mi> <m:mo>=</m:mo> <m:mrow> <m:mi>S</m:mi> <m:mo>/</m:mo> <m:mrow> <m:mo stretchy=\"false\">(</m:mo> <m:mi>ω</m:mi> <m:mo stretchy=\"false\">)</m:mo> </m:mrow> </m:mrow> </m:mrow> </m:math> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"graphic/j_forum-2023-0317_eq_0136.png\"/> <jats:tex-math>{R=S/({\\omega)}}</jats:tex-math> </jats:alternatives> </jats:inline-formula>. Precisely, there is a fully faithful triangle functor from the stable category <jats:inline-formula> <jats:alternatives> <m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\"> <m:mrow> <m:munder accentunder=\"true\"> <m:mi>𝖬𝗈𝗇</m:mi> <m:mo>¯</m:mo> </m:munder> <m:mo></m:mo> <m:mrow> <m:mo stretchy=\"false\">(</m:mo> <m:mi>ω</m:mi> <m:mo>,</m:mo> <m:mi mathvariant=\"script\">𝒢</m:mi> <m:mo stretchy=\"false\">)</m:mo> </m:mrow> </m:mrow> </m:math> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"graphic/j_forum-2023-0317_eq_0276.png\"/> <jats:tex-math>{\\underline{\\mathsf{Mon}}(\\omega,\\mathcal{G})}</jats:tex-math> </jats:alternatives> </jats:inline-formula> to <jats:inline-formula> <jats:alternatives> <m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\"> <m:mrow> <m:msub> <m:mi>𝖣</m:mi> <m:mi>𝗌𝗀</m:mi> </m:msub> <m:mo></m:mo> <m:mrow> <m:mo stretchy=\"false\">(</m:mo> <m:mi>R</m:mi> <m:mo stretchy=\"false\">)</m:mo> </m:mrow> </m:mrow> </m:math> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"graphic/j_forum-2023-0317_eq_0231.png\"/> <jats:tex-math>{\\operatorname{\\mathsf{D_{sg}}}(R)}</jats:tex-math> </jats:alternatives> </jats:inline-formula>, which is dense if and only if <jats:italic>R</jats:italic> (and so <jats:italic>S</jats:italic>) are Gorenstein rings. Particularly, it is proved that the density of the restriction of this functor to <jats:inline-formula> <jats:alternatives> <m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\"> <m:mrow> <m:munder accentunder=\"true\"> <m:mi>𝖬𝗈𝗇</m:mi> <m:mo>¯</m:mo> </m:munder> <m:mo></m:mo> <m:mrow> <m:mo stretchy=\"false\">(</m:mo> <m:mi>ω</m:mi> <m:mo>,</m:mo> <m:mi mathvariant=\"script\">𝒫</m:mi> <m:mo stretchy=\"false\">)</m:mo> </m:mrow> </m:mrow> </m:math> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"graphic/j_forum-2023-0317_eq_0277.png\"/> <jats:tex-math>{\\underline{\\mathsf{Mon}}(\\omega,\\mathcal{P})}</jats:tex-math> </jats:alternatives> </jats:inline-formula>, guarantees the regularity of the ring <jats:italic>S</jats:italic>.","PeriodicalId":12433,"journal":{"name":"Forum Mathematicum","volume":null,"pages":null},"PeriodicalIF":1.0000,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Forum Mathematicum","FirstCategoryId":"100","ListUrlMain":"https://doi.org/10.1515/forum-2023-0317","RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MATHEMATICS","Score":null,"Total":0}
引用次数: 0
Abstract
Let (S,𝔫){(S,{\mathfrak{n}})} be a commutative noetherian local ring and let ω∈𝔫{\omega\in{\mathfrak{n}}} be non-zerodivisor. This paper is concerned with the two categories of monomorphisms between finitely generated (Gorenstein) projective S-modules, such that their cokernels are annihilated by ω. It is shown that these categories, which will be denoted by 𝖬𝗈𝗇(ω,𝒫){{\mathsf{Mon}}(\omega,\mathcal{P})} and 𝖬𝗈𝗇(ω,𝒢){{\mathsf{Mon}}(\omega,\mathcal{G})}, are both Frobenius categories with the same projective objects. It is also proved that the stable category 𝖬𝗈𝗇¯(ω,𝒫){\underline{\mathsf{Mon}}(\omega,\mathcal{P})} is triangle equivalent to the category of D-branes of type B, 𝖣𝖡(ω){\mathsf{DB}(\omega)}, which has been introduced by Kontsevich and studied by Orlov. Moreover, it will be observed that the stable categories 𝖬𝗈𝗇¯(ω,𝒫){\underline{\mathsf{Mon}}(\omega,\mathcal{P})} and 𝖬𝗈𝗇¯(ω,𝒢){\underline{\mathsf{Mon}}(\omega,\mathcal{G})} are closely related to the singularity category of the factor ring R=S/(ω){R=S/({\omega)}}. Precisely, there is a fully faithful triangle functor from the stable category 𝖬𝗈𝗇¯(ω,𝒢){\underline{\mathsf{Mon}}(\omega,\mathcal{G})} to 𝖣𝗌𝗀(R){\operatorname{\mathsf{D_{sg}}}(R)}, which is dense if and only if R (and so S) are Gorenstein rings. Particularly, it is proved that the density of the restriction of this functor to 𝖬𝗈𝗇¯(ω,𝒫){\underline{\mathsf{Mon}}(\omega,\mathcal{P})}, guarantees the regularity of the ring S.
期刊介绍:
Forum Mathematicum is a general mathematics journal, which is devoted to the publication of research articles in all fields of pure and applied mathematics, including mathematical physics. Forum Mathematicum belongs to the top 50 journals in pure and applied mathematics, as measured by citation impact.