{"title":"分级理想积分依赖性的数值特征","authors":"Suprajo Das, Sudeshna Roy, Vijaylaxmi Trivedi","doi":"arxiv-2409.09346","DOIUrl":null,"url":null,"abstract":"Let $R=\\oplus_{m\\geq 0}R_m$ be a standard graded Noetherian domain over a\nfield $R_0$ and $I\\subseteq J$ be two graded ideals in $R$ such that\n$0<\\mbox{height}\\;I\\leq \\mbox{height}\\;J <d$. Then we give a set of numerical\ncharacterizations of the integral dependence of $I$ and ${J}$ in terms of\ncertain multiplicities. A novelty of the approach is that it does not involve\nlocalization and only requires checking computable and well-studied invariants. In particular, we show the following: let $S=R[Y]$, $\\mathsf{I} = IS$ and\n$\\mathsf{J} = JS$ and $\\bf d$ be the maximum generating degree of both $I$ and\n$J$. Then the following statements are equivalent. (1) $\\overline{I} = \\overline{J}$. (2) $\\varepsilon(I)=\\varepsilon(J)$ and $e_i(R[It]) = e_i(R[Jt])$ for all\n$0\\leq i <\\dim(R/I)$. (3) $e\\big(R[It]_{\\Delta_{(c,1)}}\\big) = e\\big(R[Jt]_{\\Delta_{(c,1)}}\\big)$\nand $e\\big(S[\\mathsf{I}t]_{\\Delta_{(c,1)}}\\big) =\ne\\big(S[\\mathsf{J}t]_{\\Delta_{(c,1)}}\\big)$ for some integer $c>{\\bf d}$. The statement $(2)$ generalizes the classical result of Rees. The statement\n$(3)$ gives the integral dependence criteria in terms of the Hilbert-Samuel\nmultiplicities of certain standard graded domains over $R_0$. As a consequence\nof $(3)$, we also get an equivalent statement in terms of (Teissier) mixed\nmultiplicities. Apart from several well-established results, the proofs of these results use\nthe theory of density functions which was developed recently by the authors.","PeriodicalId":501475,"journal":{"name":"arXiv - MATH - Commutative Algebra","volume":"14 1","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Numerical characterizations for integral dependence of graded ideals\",\"authors\":\"Suprajo Das, Sudeshna Roy, Vijaylaxmi Trivedi\",\"doi\":\"arxiv-2409.09346\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Let $R=\\\\oplus_{m\\\\geq 0}R_m$ be a standard graded Noetherian domain over a\\nfield $R_0$ and $I\\\\subseteq J$ be two graded ideals in $R$ such that\\n$0<\\\\mbox{height}\\\\;I\\\\leq \\\\mbox{height}\\\\;J <d$. Then we give a set of numerical\\ncharacterizations of the integral dependence of $I$ and ${J}$ in terms of\\ncertain multiplicities. A novelty of the approach is that it does not involve\\nlocalization and only requires checking computable and well-studied invariants. In particular, we show the following: let $S=R[Y]$, $\\\\mathsf{I} = IS$ and\\n$\\\\mathsf{J} = JS$ and $\\\\bf d$ be the maximum generating degree of both $I$ and\\n$J$. Then the following statements are equivalent. (1) $\\\\overline{I} = \\\\overline{J}$. (2) $\\\\varepsilon(I)=\\\\varepsilon(J)$ and $e_i(R[It]) = e_i(R[Jt])$ for all\\n$0\\\\leq i <\\\\dim(R/I)$. (3) $e\\\\big(R[It]_{\\\\Delta_{(c,1)}}\\\\big) = e\\\\big(R[Jt]_{\\\\Delta_{(c,1)}}\\\\big)$\\nand $e\\\\big(S[\\\\mathsf{I}t]_{\\\\Delta_{(c,1)}}\\\\big) =\\ne\\\\big(S[\\\\mathsf{J}t]_{\\\\Delta_{(c,1)}}\\\\big)$ for some integer $c>{\\\\bf d}$. The statement $(2)$ generalizes the classical result of Rees. The statement\\n$(3)$ gives the integral dependence criteria in terms of the Hilbert-Samuel\\nmultiplicities of certain standard graded domains over $R_0$. As a consequence\\nof $(3)$, we also get an equivalent statement in terms of (Teissier) mixed\\nmultiplicities. Apart from several well-established results, the proofs of these results use\\nthe theory of density functions which was developed recently by the authors.\",\"PeriodicalId\":501475,\"journal\":{\"name\":\"arXiv - MATH - Commutative Algebra\",\"volume\":\"14 1\",\"pages\":\"\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2024-09-14\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"arXiv - MATH - Commutative Algebra\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/arxiv-2409.09346\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"arXiv - MATH - Commutative Algebra","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/arxiv-2409.09346","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
Numerical characterizations for integral dependence of graded ideals
Let $R=\oplus_{m\geq 0}R_m$ be a standard graded Noetherian domain over a
field $R_0$ and $I\subseteq J$ be two graded ideals in $R$ such that
$0<\mbox{height}\;I\leq \mbox{height}\;J {\bf d}$. The statement $(2)$ generalizes the classical result of Rees. The statement
$(3)$ gives the integral dependence criteria in terms of the Hilbert-Samuel
multiplicities of certain standard graded domains over $R_0$. As a consequence
of $(3)$, we also get an equivalent statement in terms of (Teissier) mixed
multiplicities. Apart from several well-established results, the proofs of these results use
the theory of density functions which was developed recently by the authors.