On the dynamics of Toeplitz operators over Bergman spaces

Abstract

We investigate the hypercyclicity of Toeplitz operators on the Bergman space $L_{A}^{2}(\mathbb{D})$ with symbols of the form $Ψ(z) = γ\bar{z}+ψ(z)$, where $γ\in \mathbb{C} \setminus \{0\}$ and $ψ$ is analytic on an open neighborhood of the closed unit disc $\overline{\mathbb{D}}$. Our approach bypasses the classical Hardy space techniques (reproducing kernel linear combinations, Nevanlinna factorization) by directly solving the integro-differential resolvent equation arising from the Bergman projection. A key winding number argument shows that for sense-reversing symbols ($|γ| > \sup_{z \in \overline{\mathbb{D}}} |ψ'(z)|$), the symbol's image $Ψ(\mathbb{D})$ is contained in the point spectrum of $T_Ψ$. In the tridiagonal case $Ψ(z) = a\bar{z}+b+cz$, we fully resolve the longstanding eigenvector completeness problem by linking the recurrence coefficients to a rotated Favard spectral measure on the major axis of the symbol's ellipse. Combined with self-commutator positivity, this establishes an unconditional, exact necessary and sufficient characterization of hypercyclicity: $T_Ψ$ is hypercyclic if and only if $|a| > |c|$ and $Ψ(\mathbb{D})$ intersects both the unit disc and its exterior, completely eliminating the $(3+\sqrt{2})$ restriction of previous literature.