A sagbi basis for the quantum Grassmannian

dc.creatorSottile, Frank
dc.creatorSturmfels, Bernd
dc.date1999-08-03
dc.date.accessioned2026-07-07T05:30:11Z
dc.date.available2026-07-07T05:30:11Z
dc.descriptionThe maximal minors of a p by (m + p) matrix of univariate polynomials of degree n with indeterminate coefficients are themselves polynomials of degree np. The subalgebra generated by their coefficients is the coordinate ring of the quantum Grassmannian, a singular compactification of the space of rational curves of degree np in the Grassmannian of p-planes in (m + p)-space. These subalgebra generators are shown to form a sagbi basis. The resulting flat deformation from the quantum Grassmannian to a toric variety gives a new `Gröbner basis style' proof of the Ravi-Rosenthal-Wang formulas in quantum Schubert calculus. The coordinate ring of the quantum Grassmannian is an algebra with straightening law, which is normal, Cohen-Macaulay, Gorenstein and Koszul, and the ideal of quantum Plücker relations has a quadratic Gröbner basis. This holds more generally for skew quantum Schubert varieties. These results are well-known for the classical Schubert varieties (n=0). We also show that the row-consecutive p by p-minors of a generic matrix form a sagbi basis and we give a quadratic Gröbner basis for their algebraic relations.
dc.description18 pages, 3 eps figure, uses epsf.sty. Dedicated to the memory of Gian-Carlo Rota
dc.identifierhttps://arxiv.org/abs/math/9908016
dc.identifierhttp://arxiv.org/abs/math/9908016
dc.identifierJ. Pure and Appl. Algebra, 158, 24 April 2001 pp. 347-366
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/78913
dc.subjectAlgebraic Geometry
dc.subjectCommutative Algebra
dc.subjectCombinatorics
dc.subject13P10, 13F50, 14M12, 14M15, 14M17
dc.titleA sagbi basis for the quantum Grassmannian
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