Results 11 to 20 of about 285,691 (303)

Total positivity, Schubert positivity, and geometric Satake [PDF]

open access: yesJournal of Algebra, 2016
Let G be a simple and simply-connected complex algebraic group, and let X \subset G^\vee be the centralizer subgroup of a principal nilpotent element. Ginzburg and Peterson independently related the ring of functions on X with the homology ring of the affine Grassmannian Gr_G.
Lam, Thomas, Rietsch, Konstanze
openaire   +7 more sources

Hyperdeterminantal Total Positivity [PDF]

open access: yesSymmetry, Integrability and Geometry: Methods and Applications
For a given positive integer $m$, the concept of <I>hyperdeterminantal total positivity</I> is defined for a kernel $K\colon {\mathbb R}^{2m} \to {\mathbb R}$, thereby generalizing the classical concept of total positivity. Extending the fundamental example, $K(x,y) = \exp(xy)$, $x, y \in \mathbb{R}$, of a classical totally positive kernel,
Johnson, Kenneth W.   +1 more
openaire   +4 more sources

Total Positivity and Convexity Preservation [PDF]

open access: yesJournal of Approximation Theory, 1999
In this paper the author introduces a concept of \(d\)-convexity of curves in the \(d\)-dimensional space and characterizes totally positive blending systems in terms of \(d\)-convexity. He shows that for certain systems total positivity and rational convexity preservation are equivalent.
Floater, Michael S.
openaire   +3 more sources

Positive Hankel Matrices, Eigenvalues and Total Positivity [PDF]

open access: yesMathematics
For positive Hankel matrices, an interval containing all eigenvalues is obtained. With a stronger condition, we also construct two sharper intervals for the eigenvalue localization. The total positivity of positive Hankel matrices is analyzed.
Juan Manuel Peña
doaj   +2 more sources

The total positivity interval [PDF]

open access: yesLinear Algebra and its Applications, 2004
The authors consider the important descriptors: totally positive, and the related terms (totally nonnegative and oscillatory). They define the concept of the total positivity interval of such matrices. They seek concretely this interval and investigate some properties of this.
Gladwell, G.M.L., Ghanbari, K.
openaire   +3 more sources

Total positivity and dependence of order statistics [PDF]

open access: yes, 2023
In this comprehensive study, we delve deeply into the concept of multivariate total positivity, defining it in accordance with a direction. We rigorously explore numerous salient properties, shedding light on the nuances that characterize this notion ...
Amo Artero, Enrique de   +4 more
core   +1 more source

Total positivity order and the normal distribution [PDF]

open access: yes, 2006
International audienceUnlike the usual stochastic order, total positivity order is closed under conditioning. Here we provide a general formulation of the preservation properties of the order under conditioning; we study certain properties of the order ...
Marco Scarsini   +3 more
core   +3 more sources

Combinatorics of Positroids [PDF]

open access: yesDiscrete Mathematics & Theoretical Computer Science, 2009
Recently Postnikov gave a combinatorial description of the cells in a totally-nonnegative Grassmannian. These cells correspond to a special class of matroids called positroids.
Suho Oh
doaj   +1 more source

Totally positive matrices and totally positive hypergraphs

open access: yesLinear Algebra and its Applications, 2001
This paper characterizes (0,1)-matrices which are totally positive, that is, all their minors are totally positive. First the case of \(1\times 1\) and \(2\times 2\) minors is characterized in terms of interval hypergraphs and then the general case is characterized in terms of a chain of cliques \(C_i\), \(C_i\cap C_j = \emptyset \Leftrightarrow |i-j ...
Kubicki, Grzegorz   +2 more
openaire   +2 more sources

On the Total Positivity and Accurate Computations of r-Bell Polynomial Bases

open access: yesAxioms, 2023
A new class of matrices defined in terms of r-Stirling numbers is introduced. These r-Stirling matrices are totally positive and determine the linear transformation between monomial and r-Bell polynomial bases.
Esmeralda Mainar   +2 more
doaj   +1 more source

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