Separately radial and radial Toeplitz operators on the projective space and representation theory

Raul Quiroga-Barranco; Armando Sanchez-Nungaray

Displaying similar documents to “Separately radial and radial Toeplitz operators on the projective space and representation theory”

On products of some Toeplitz operators on polyanalytic Fock spaces

Irène Casseli (2020)

Czechoslovak Mathematical Journal

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The purpose of this paper is to study the Sarason’s problem on Fock spaces of polyanalytic functions. Namely, given two polyanalytic symbols $f$ and $g$ , we establish a necessary and sufficient condition for the boundedness of some Toeplitz products $T_{f} T_{\bar{g}}$ subjected to certain restriction on $f$ and $g$ . We also characterize this property in terms of the Berezin transform.

On the powers of quasihomogeneous Toeplitz operators

Aissa Bouhali, Zohra Bendaoud, Issam Louhichi (2021)

Czechoslovak Mathematical Journal

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We present sufficient conditions for the existence of $p$ th powers of a quasihomogeneous Toeplitz operator $T_{e^{i s θ} ψ}$ , where $ψ$ is a radial polynomial function and $p$ , $s$ are natural numbers. A large class of examples is provided to illustrate our results. To our best knowledge those examples are not covered by the current literature. The main tools in the proof of our results are the Mellin transform and some classical theorems of complex analysis.

Compression of slant Toeplitz operators on the Hardy space of $n$ -dimensional torus

Gopal Datt, Shesh Kumar Pandey (2020)

Czechoslovak Mathematical Journal

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This paper studies the compression of a $k$ th-order slant Toeplitz operator on the Hardy space $H^{2} (𝕋^{n})$ for integers $k \geq 2$ and $n \geq 1$ . It also provides a characterization of the compression of a $k$ th-order slant Toeplitz operator on $H^{2} (𝕋^{n})$ . Finally, the paper highlights certain properties, namely isometry, eigenvalues, eigenvectors, spectrum and spectral radius of the compression of $k$ th-order slant Toeplitz operator on the Hardy space $H^{2} (𝕋^{n})$ of $n$ -dimensional torus $𝕋^{n}$ .

Schatten class generalized Toeplitz operators on the Bergman space

Chunxu Xu, Tao Yu (2021)

Czechoslovak Mathematical Journal

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Let $μ$ be a finite positive measure on the unit disk and let $j \geq 1$ be an integer. D. Suárez (2015) gave some conditions for a generalized Toeplitz operator $T_{μ}^{(j)}$ to be bounded or compact. We first give a necessary and sufficient condition for $T_{μ}^{(j)}$ to be in the Schatten $p$ -class for $1 \leq p < \infty$ on the Bergman space $A^{2}$ , and then give a sufficient condition for $T_{μ}^{(j)}$ to be in the Schatten $p$ -class $(0 < p < 1)$ on $A^{2}$ . We also discuss the generalized Toeplitz operators with general bounded symbols. If $ϕ \in L^{\infty} (D, d A)$ and $1 < p < \infty$ , we define the generalized...

Complex symmetry of Toeplitz operators on the weighted Bergman spaces

Xiao-He Hu (2022)

Czechoslovak Mathematical Journal

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We give a concrete description of complex symmetric monomial Toeplitz operators $T_{z^{p} {\bar{z}}^{q}}$ on the weighted Bergman space $A^{2} (Ω)$ , where $Ω$ denotes the unit ball or the unit polydisk. We provide a necessary condition for $T_{z^{p} {\bar{z}}^{q}}$ to be complex symmetric. When $p, q \in ℕ^{2}$ , we prove that $T_{z^{p} {\bar{z}}^{q}}$ is complex symmetric on $A^{2} (Ω)$ if and only if $p_{1} = q_{2}$ and $p_{2} = q_{1}$ . Moreover, we completely characterize when monomial Toeplitz operators $T_{z^{p} {\bar{z}}^{q}}$ on $A^{2} (𝔻_{n})$ are $J_{U}$ -symmetric with the $n \times n$ symmetric unitary matrix $U$ .

Toeplitz operators on Bergman spaces and Hardy multipliers

Wolfgang Lusky, Jari Taskinen (2011)

Studia Mathematica

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We study Toeplitz operators $T_{a}$ with radial symbols in weighted Bergman spaces $A_{μ}^{p}$ , 1 < p < ∞, on the disc. Using a decomposition of $A_{μ}^{p}$ into finite-dimensional subspaces the operator $T_{a}$ can be considered as a coefficient multiplier. This leads to new results on boundedness of $T_{a}$ and also shows a connection with Hardy space multipliers. Using another method we also prove a necessary and sufficient condition for the boundedness of $T_{a}$ for a satisfying an assumption on the positivity of certain...

The generalized Toeplitz operators on the Fock space $F_{α}^{2}$

Chunxu Xu, Tao Yu (2024)

Czechoslovak Mathematical Journal

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Let $μ$ be a positive Borel measure on the complex plane $ℂ^{n}$ and let $j = (j_{1}, \dots, j_{n})$ with $j_{i} \in ℕ$ . We study the generalized Toeplitz operators $T_{μ}^{(j)}$ on the Fock space $F_{α}^{2}$ . We prove that $T_{μ}^{(j)}$ is bounded (or compact) on $F_{α}^{2}$ if and only if $μ$ is a Fock-Carleson measure (or vanishing Fock-Carleson measure). Furthermore, we give a necessary and sufficient condition for $T_{μ}^{(j)}$ to be in the Schatten $p$ -class for $1 \leq p < \infty$ .

Coefficient inequality for a function whose derivative has a positive real part of order $α$

Deekonda Vamshee Krishna, Thoutreddy Ramreddy (2015)

Mathematica Bohemica

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The objective of this paper is to obtain sharp upper bound for the function $f$ for the second Hankel determinant $| a_{2} a_{4} - a_{3}^{2} |$ , when it belongs to the class of functions whose derivative has a positive real part of order $α$ $(0 \leq α < 1)$ , denoted by $R T (α)$ . Further, an upper bound for the inverse function of $f$ for the nonlinear functional (also called the second Hankel functional), denoted by $| t_{2} t_{4} - t_{3}^{2} |$ , was determined when it belongs to the same class of functions, using Toeplitz determinants.

Area differences under analytic maps and operators

Mehmet Çelik, Luke Duane-Tessier, Ashley Marcial Rodriguez, Daniel Rodriguez, Aden Shaw (2024)

Czechoslovak Mathematical Journal

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Motivated by the relationship between the area of the image of the unit disk under a holomorphic mapping $h$ and that of $z h$ , we study various $L^{2}$ norms for $T_{ϕ} (h)$ , where $T_{ϕ}$ is the Toeplitz operator with symbol $ϕ$ . In Theorem , given polynomials $p$ and $q$ we find a symbol $ϕ$ such that $T_{ϕ} (p) = q$ . We extend some of our results to the polydisc.

Product equivalence of quasihomogeneous Toeplitz operators on the harmonic Bergman space

Xing-Tang Dong, Ze-Hua Zhou (2013)

Studia Mathematica

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We present here a quite unexpected result: If the product of two quasihomogeneous Toeplitz operators $T_{f} T_{g}$ on the harmonic Bergman space is equal to a Toeplitz operator $T_{h}$ , then the product $T_{g} T_{f}$ is also the Toeplitz operator $T_{h}$ , and hence $T_{f}$ commutes with $T_{g}$ . From this we give necessary and sufficient conditions for the product of two Toeplitz operators, one quasihomogeneous and the other monomial, to be a Toeplitz operator.

The essential spectrum of Toeplitz tuples with symbols in $H^{\infty} + C$

Jörg Eschmeier (2013)

Studia Mathematica

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Let H²(D) be the Hardy space on a bounded strictly pseudoconvex domain D ⊂ ℂⁿ with smooth boundary. Using Gelfand theory and a spectral mapping theorem of Andersson and Sandberg (2003) for Toeplitz tuples with $H^{\infty}$ -symbol, we show that a Toeplitz tuple $T_{f} = (T_{f ₁}, . . ., T_{f ₘ}) \in L {(H ² (σ))}^{m}$ with symbols $f_{i} \in H^{\infty} + C$ is Fredholm if and only if the Poisson-Szegö extension of f is bounded away from zero near the boundary of D. Corresponding results are obtained for the case of Bergman spaces. Thus we extend results of McDonald (1977) and...

The relationship between $K_{u}^{2} \cap v H^{2}$ and inner functions

Xiaoyuan Yang (2024)

Czechoslovak Mathematical Journal

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Let $u$ be an inner function and $K_{u}^{2}$ be the corresponding model space. For an inner function $v$ , the subspace $v H^{2}$ is an invariant subspace of the unilateral shift operator on $H^{2}$ . In this article, using the structure of a Toeplitz kernel $\ker T_{\bar{u} v}$ , we study the intersection $K_{u}^{2} \cap v H^{2}$ by properties of inner functions $u$ and $v$ $(v \neq u)$ . If $K_{u}^{2} \cap v H^{2} \neq {0}$ , then there exists a triple $(B, b, g)$ such that $\bar{u} v = \frac{λ b \bar{B O_{g}}}{g},$ where the triple $(B, b, g)$ means that $B$ and $b$ are Blaschke products, $g$ is an invertible function in $H^{\infty}$ , $O_{g}$ denotes the outer factor...

Characterizing projective general unitary groups ${PGU}_{3} (q^{2})$ by their complex group algebras

Farrokh Shirjian, Ali Iranmanesh (2017)

Czechoslovak Mathematical Journal

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Let $G$ be a finite group. Let $X_{1} (G)$ be the first column of the ordinary character table of $G$ . We will show that if $X_{1} (G) = X_{1} ({PGU}_{3} (q^{2}))$ , then $G ≅ {PGU}_{3} (q^{2})$ . As a consequence, we show that the projective general unitary groups ${PGU}_{3} (q^{2})$ are uniquely determined by the structure of their complex group algebras.

The essential spectrum of holomorphic Toeplitz operators on $H^{p}$ spaces

Mats Andersson, Sebastian Sandberg (2003)

Studia Mathematica

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We compute the essential Taylor spectrum of a tuple of analytic Toeplitz operators $T_{g}$ on $H^{p} (D)$ , where D is a strictly pseudoconvex domain. We also provide specific formulas for the index of $T_{g}$ provided that $g^{- 1} (0)$ is a compact subset of D.