{"title":"Global dimension of real-exponent polynomial rings","authors":"Nathan Geist, Ezra Miller","doi":"10.2140/ant.2023.17.1779","DOIUrl":null,"url":null,"abstract":"<p>The ring <math display=\"inline\" xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>R</mi></math> of real-exponent polynomials in <math display=\"inline\" xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>n</mi></math> variables over any field has global dimension <math display=\"inline\" xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>n</mi>\n<mo>+</mo> <mn>1</mn></math> and flat dimension <math display=\"inline\" xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>n</mi></math>. In particular, the residue field <math display=\"inline\" xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi> k</mi><mo> <!--FUNCTION APPLICATION--> </mo><!--nolimits-->\n<mo>=</mo>\n<mi>R</mi><mo>∕</mo><mi mathvariant=\"fraktur\">𝔪</mi></math> of <math display=\"inline\" xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>R</mi></math> modulo its maximal graded ideal <math display=\"inline\" xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi mathvariant=\"fraktur\">𝔪</mi></math> has flat dimension <math display=\"inline\" xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>n</mi></math> via a Koszul-like resolution. Projective and flat resolutions of all <math display=\"inline\" xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>R</mi></math>-modules are constructed from this resolution of <math display=\"inline\" xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi> k</mi><mo> <!--FUNCTION APPLICATION--> </mo><!--nolimits--></math>. The same results hold when <math display=\"inline\" xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>R</mi></math> is replaced by the monoid algebra for the positive cone of any subgroup of <math display=\"inline\" xmlns=\"http://www.w3.org/1998/Math/MathML\"><msup><mrow><mi>ℝ</mi></mrow><mrow><mi>n</mi></mrow></msup></math> satisfying a mild density condition. </p>","PeriodicalId":50828,"journal":{"name":"Algebra & Number Theory","volume":"12 24","pages":""},"PeriodicalIF":0.9000,"publicationDate":"2023-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"1","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Algebra & Number Theory","FirstCategoryId":"100","ListUrlMain":"https://doi.org/10.2140/ant.2023.17.1779","RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MATHEMATICS","Score":null,"Total":0}
引用次数: 1
Abstract
The ring of real-exponent polynomials in variables over any field has global dimension and flat dimension . In particular, the residue field of modulo its maximal graded ideal has flat dimension via a Koszul-like resolution. Projective and flat resolutions of all -modules are constructed from this resolution of . The same results hold when is replaced by the monoid algebra for the positive cone of any subgroup of satisfying a mild density condition.
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