1. On the topological boundary of the one-sided spectrum Creator: Müller, Vladimír Format: bez média and svazek Type: model:article and TEXT Subject: math and topological boundary of the spectrum of an operator Language: English Description: It is well-known that the topological boundary of the spectrum of an operator is contained in the approximate point spectrum. We show that the one-sided version of this result is not true. This gives also a negative answer to a problem of Schmoeger. Rights: http://creativecommons.org/publicdomain/mark/1.0/ and policy:public