A proof of Sn-i (a11,..., ann) ≥ Sn-i (λ1,..., λn), 0 ≤ i ≤ n - 1 for an n × n positive definite symmetric matrix A = [aij]nxn, using mixed determinants

dc.contributor.authorPranayanuntana, Poramate
dc.date.accessioned2026-08-06T09:55:10Z
dc.date.available2026-08-06T09:55:10Z
dc.date.issued2007-01-01
dc.description.abstractBy using mixed determinant of special form D (A, n - i; I, i) for positive definite symmetric matrix A, in particular the operator concavity property of the map f : A → D<sup>1/(n-i)</sup> (A, n - i; I, i)I together with unital positive linear map Φ : A → A ο I the Hadamard product of A with the identity matrix I, inequalities of the form S<inf>n-i</inf>(a<inf>11</inf>,..., a<inf>nn</inf>) ≥ S<inf>n-i</inf>(λ<inf>1</inf>,..., λ<inf>n</inf>), 0 ≤ i ≤ n - 1 for an n × n positive definite symmetric matrix A = [a<inf>ij</inf>] with S<inf>k</inf> : IR<sup>n</sup> → IR, k = 1, 2,...,n defined by S<inf>k</inf>(χ) := ∑<inf>1</inf>≤i<inf>1</inf><i<inf>2</inf><...< i<inf>k</inf>≤n χ<inf>i1</inf> χ<inf>i2</inf> · χ<inf>ik</inf>, and called the elementary symmetric polynomials and λ<inf>i</inf>, i = 1, 2,...,n the eigenvalues of A, are derived. This result was first proved using Schur-concavity property of the elementary symmetric function S<inf>k</inf> (χ) together with the fact that for any positive definite symmetric matrix A, the vector of its diagonal entries is majorized by the vector of its eigenvalues. Hence, this suggests relationship among mixed determinant, majorization and Schur-concavity.
dc.identifier.citationWseas Transactions on Mathematics, 6(1), 195-204, 2007
dc.identifier.issn11092769
dc.identifier.other2-s2.0-33751576834
dc.identifier.urihttps://dspace.kmitl.ac.th/handle/123456789/1595
dc.sourceWseas Transactions on Mathematics
dc.subjectAleksandrov inequality
dc.subjectDoubly stochastic matrix
dc.subjectElementary symmetric polynomial
dc.subjectMajorization
dc.subjectMatrix Hadamard product
dc.subjectMixed determinant
dc.subjectOperator concave function
dc.subjectOperator convex function
dc.subjectOperator monotone function
dc.subjectSchur-concave function
dc.subjectSchur-convex function
dc.subjectUnital positive linear map
dc.titleA proof of Sn-i (a11,..., ann) ≥ Sn-i (λ1,..., λn), 0 ≤ i ≤ n - 1 for an n × n positive definite symmetric matrix A = [aij]nxn, using mixed determinants
dc.typeArticle

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