5 papers · 1 filter
A bounded globally univalent quasiconformal harmonic map whose analytic part is unbounded
David Kalaj
We construct, for every \(0<k<1\), a bounded globally univalent harmonic mapping \[ f=h+\overline g \colon \D\to\C \] such that \[ |g'(z)|\le k|h'(z)|,\qquad z\in\D, \] while the a…
The Norm of the Interior Cauchy Transform: Beyond the First Dirichlet Eigenvalue
David Kalaj
We study sharp \(L^2\) bounds for the interior Cauchy transform \(C_D\) on a bounded planar domain \(D\) and clarify its connection with the Dirichlet spectrum. We analyze an appro…
The -Norm of the Cauchy transform on circular annuli
David Kalaj
We compute the exact operator norm of the Cauchy transform \[ (C_Ωf)(z)=\frac1Ï\int_Ω\frac{f(w)}{z-w}\,dA(w) \] on a circular annulus . Exploiting r…
On generalized M. Riesz conjugate function theorem for harmonic mappings
Anton Gjokaj, David Kalaj, Djordjije Vujadinovic
Let be the Lesbegue space of complex-valued functions defined in the unit circle . In this paper, we address the prob…
Zygmund theorem for harmonic quasiregular mappings
David Kalaj
Let . We prove Zygmund theorem for quasiregular harmonic mappings in the unit disk in the complex plane by providing a constant in the inequality $$…