Absolute continuity for Jacobi matrices with power-like weights

Wojciech Motyka

Displaying similar documents to “Absolute continuity for Jacobi matrices with power-like weights”

Hamilton-Jacobi flows and characterization of solutions of Aronsson equations

Petri Juutinen, Eero Saksman (2007)

Annali della Scuola Normale Superiore di Pisa - Classe di Scienze

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In this note, we verify the conjecture of Barron, Evans and Jensen [3] regarding the characterization of viscosity solutions of general Aronsson equations in terms of the properties of associated forward and backwards Hamilton-Jacobi flows. A special case of this result is analogous to the characterization of infinity harmonic functions in terms of convexity and concavity of the functions $r \mapsto {max}_{y \in B_{r} (x)} u (y)$ and $r \mapsto {min}_{y \in B_{r} (x)} u (y)$ , respectively.

Nested matrices and inverse $M$ -matrices

Jeffrey L. Stuart (2015)

Czechoslovak Mathematical Journal

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Given a sequence of real or complex numbers, we construct a sequence of nested, symmetric matrices. We determine the $L U$ - and $Q R$ -factorizations, the determinant and the principal minors for such a matrix. When the sequence is real, positive and strictly increasing, the matrices are strictly positive, inverse $M$ -matrices with symmetric, irreducible, tridiagonal inverses.

Jacobi decomposition of weighted Triebel-Lizorkin and Besov spaces

George Kyriazis, Pencho Petrushev, Yuan Xu (2008)

Studia Mathematica

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The Littlewood-Paley theory is extended to weighted spaces of distributions on [-1,1] with Jacobi weights $w (t) = {(1 - t)}^{α} {(1 + t)}^{β}$ . Almost exponentially localized polynomial elements (needlets) $φ_{ξ}$ , $ψ_{ξ}$ are constructed and, in complete analogy with the classical case on ℝⁿ, it is shown that weighted Triebel-Lizorkin and Besov spaces can be characterized by the size of the needlet coefficients $⟨ f, φ_{ξ} ⟩$ in respective sequence spaces.

Torsion points on curves and common divisors of $a^{k} - 1$ and $b^{k} - 1$

Nir Ailon, Zéev Rudnick (2004)

Acta Arithmetica

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A generalization of Bateman's expansion and finite integrals of Sonine's and Feldheim's type

Giacomo Gigante (2010)

Colloquium Mathematicae

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Let ${A_{k}}_{k = 0}^{+ \infty}$ be a sequence of arbitrary complex numbers, let α,β > -1, let Pₙα,βn=0+∞ $b e t h e J a c o b i p o l y n o m i a l s a n d d e f i n e t h e f u n c t i o n s$ $H ₙ (α, z) = \sum_{m = n}^{+ \infty} (A_{m} z^{m}) / (Γ (α + n + m + 1) (m - n)!)$ , $G (α, β, x, y) = \sum_{r, s = 0}^{+ \infty} (A_{r + s} x^{r} y^{s}) / (Γ (α + r + 1) Γ (β + s + 1) r! s!)$ . Then, for any non-negative integer n, $\int_{0}^{π / 2} G (α, β, x ² s i n ² ϕ, y ² c o s ² ϕ) P ₙ^{α, β} (c o s ² ϕ) s i n^{2 α + 1} ϕ c o s^{2 β + 1} ϕ d = 1 / 2 H ₙ (α + β + 1, x ² + y ²) P ₙ^{α, β} ((y ² - x ²) / (y ² + x ²))$ . When $A_{k} = {(- 1 / 4)}^{k}$ , this formula reduces to Bateman’s expansion for Bessel functions. For particular values of y and n one obtains generalizations of several formulas already known for Bessel functions, like Sonine’s first and second finite integrals and certain Neumann series expansions. Particular choices of ${A_{k}}_{k = 0}^{+ \infty}$ allow one to write all these type of formulas...

Doubly stochastic matrices and the Bruhat order

Richard A. Brualdi, Geir Dahl, Eliseu Fritscher (2016)

Czechoslovak Mathematical Journal

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The Bruhat order is defined in terms of an interchange operation on the set of permutation matrices of order $n$ which corresponds to the transposition of a pair of elements in a permutation. We introduce an extension of this partial order, which we call the stochastic Bruhat order, for the larger class $Ω_{n}$ of doubly stochastic matrices (convex hull of $n \times n$ permutation matrices). An alternative description of this partial order is given. We define a class of special faces of $Ω_{n}$ induced by permutation...

An improvement of an inequality of Fiedler leading to a new conjecture on nonnegative matrices

Assaf Goldberger, Neumann, Michael (2004)

Czechoslovak Mathematical Journal

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Suppose that $A$ is an $n \times n$ nonnegative matrix whose eigenvalues are $λ = ρ (A), λ_{2}, ..., λ_{n}$ . Fiedler and others have shown that $det (λ I - A) \leq λ^{n} - ρ^{n}$ , for all $λ > ρ$ , with equality for any such $λ$ if and only if $A$ is the simple cycle matrix. Let $a_{i}$ be the signed sum of the determinants of the principal submatrices of $A$ of order $i \times i$ , $i = 1, ..., n - 1$ . We use similar techniques to Fiedler to show that Fiedler’s inequality can be strengthened to: $det (λ I - A) + \sum_{i = 1}^{n - 1} ρ^{n - 2 i} | a_{i} | {(λ - ρ)}^{i} \leq λ^{n} - ρ^{n}$ , for all $λ \geq ρ$ . We use this inequality to derive the inequality that: $\prod_{2}^{n} (ρ - λ_{i}) \leq ρ^{n - 2} \sum_{i = 2}^{n} (ρ - λ_{i})$ . In the spirit of a celebrated conjecture...

Vandermonde nets

Roswitha Hofer, Harald Niederreiter (2014)

Acta Arithmetica

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The second-named author recently suggested identifying the generating matrices of a digital (t,m,s)-net over the finite field $_{q}$ with an s × m matrix C over $_{q^{m}}$ . More exactly, the entries of C are determined by interpreting the rows of the generating matrices as elements of $_{q^{m}}$ . This paper introduces so-called Vandermonde nets, which correspond to Vandermonde-type matrices C, and discusses the quality parameter and the discrepancy of such nets. The methods that have been successfully used...

On the matrix negative Pell equation

Aleksander Grytczuk, Izabela Kurzydło (2009)

Discussiones Mathematicae - General Algebra and Applications

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Let N be a set of natural numbers and Z be a set of integers. Let M₂(Z) denotes the set of all 2x2 matrices with integer entries. We give necessary and suficient conditions for solvability of the matrix negative Pell equation (P) X² - dY² = -I with d ∈ N for nonsingular X,Y belonging to M₂(Z) and his generalization (Pn) $\sum_{i = 1}^{n} X ₂_{i} - d \sum_{i = 1}^{n} Y ²_{i} = - I$ with d ∈ N for nonsingular $X_{i}, Y_{i} \in M ₂ (Z)$ , i=1,...,n.

A method to rigorously enclose eigenpairs of complex interval matrices

Castelli, Roberto, Lessard, Jean-Philippe

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In this paper, a rigorous computational method to enclose eigenpairs of complex interval matrices is proposed. Each eigenpair $x = (λ,)$ is found by solving a nonlinear equation of the form $f (x) = 0$ via a contraction argument. The set-up of the method relies on the notion of $r a d i i p o l y n o m i a l s$ , which provide an efficient mean of determining a domain on which the contraction mapping theorem is applicable.

Localization of dominant eigenpairs and planted communities by means of Frobenius inner products

Dario Fasino, Francesco Tudisco (2016)

Czechoslovak Mathematical Journal

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We propose a new localization result for the leading eigenvalue and eigenvector of a symmetric matrix $A$ . The result exploits the Frobenius inner product between $A$ and a given rank-one landmark matrix $X$ . Different choices for $X$ may be used, depending on the problem under investigation. In particular, we show that the choice where $X$ is the all-ones matrix allows to estimate the signature of the leading eigenvector of $A$ , generalizing previous results on Perron-Frobenius properties of matrices...

A spectral gap theorem in SU $(d)$

Jean Bourgain, Alex Gamburd (2012)

Journal of the European Mathematical Society

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We establish the spectral gap property for dense subgroups of SU $(d)$ $(d \geq 2)$ , generated by finitely many elements with algebraic entries; this result was announced in [BG3]. The method of proof differs, in several crucial aspects, from that used in [BG] in the case of SU $(2)$ .

On the spectral radius in $L_{1} (G)$

E. Porada (1971)

Colloquium Mathematicae

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Almost everywhere convergence of the inverse Jacobi transform and endpoint results for a disc multiplier

Troels Roussau Johansen (2011)

Studia Mathematica

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The maximal operator S⁎ for the spherical summation operator (or disc multiplier) $S_{R}$ associated with the Jacobi transform through the defining relation $\hat{S_{R} f} (λ) = 1_{| λ | \leq R} f ̂ (t)$ for a function f on ℝ is shown to be bounded from $L^{p} (ℝ ₊, d μ)$ into $L^{p} (ℝ, d μ) + L ² (ℝ, d μ)$ for (4α + 4)/(2α + 3) < p ≤ 2. Moreover S⁎ is bounded from $L^{p ₀, 1} (ℝ ₊, d μ)$ into $L^{p ₀, \infty} (ℝ, d μ) + L ² (ℝ, d μ)$ . In particular ${S_{R} f (t)}_{R > 0}$ converges almost everywhere towards f, for $f \in L^{p} (ℝ ₊, d μ)$ , whenever (4α + 4)/(2α + 3) < p ≤ 2.

Spectral Asymptotics for the $\bar{\partial}$ -Neumann Problem

Guy Métivier (1981-1982)

Publications mathématiques et informatique de Rennes

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