On Hyponormality on the Bergman Space of an Annulus
A bounded operator S on a Hilbert space is hyponormal if S∗S−SS∗ is positive. In this work we find necessary conditions for the hyponormality of the Toeplitz operator Tφ+ψ¯ on the Bergman space of the annulus {1/2<|z|<1} where both φ and ψ are bounded and analytic on the annulus and are of the form ∑n≥1anzn+bn1zn.