We investigate the relationship between the Bergman shift operator and the
support of the corresponding measure. We pay special attention to the situation
when the measure of orthogonality is concentrated on a polynomial lemniscate.
As an application of our new results, we obtain a ratio asymptotic result for a
wide variety of measures supported on polynomial lemniscates.Comment: 15 pages; version 2: small correction to Lemma 4.1, extended
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