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Summary:
In this paper we obtain some results concerning the set ${\mathcal M} = \cup \bigl \lbrace \overline{R(\delta _A)}\cap \lbrace A\rbrace ^{\prime }\: A\in {\mathcal L(H)}\bigr \rbrace $, where $\overline{R(\delta _A)}$ is the closure in the norm topology of the range of the inner derivation $\delta _A$ defined by $\delta _A (X) = AX - XA.$ Here $\mathcal H$ stands for a Hilbert space and we prove that every compact operator in $\overline{R(\delta _A)}^w\cap \lbrace A^*\rbrace ^{\prime }$ is quasinilpotent if $A$ is dominant, where $\overline{R(\delta _A)}^w$ is the closure of the range of $\delta _A$ in the weak topology.
References:
[1] J.H.Anderson: On normal derivations. Proc. Amer. Math. Soc. 38 (1973), 135–140.. DOI 10.1090/S0002-9939-1973-0312313-6 | MR 0312313 | Zbl 0255.47036
[2] J.H.Anderson: Derivation ranges and the identity. Bull. Amer. Math. Soc. 79 (1973), 705–708.. DOI 10.1090/S0002-9904-1973-13271-9 | MR 0322518 | Zbl 0269.47021
[3] D.C.Kleïnecke: On operator commutators. Proc. Amer. Math. Soc. 8 (1957), 535–536.. DOI 10.1090/S0002-9939-1957-0087914-4 | MR 0087914 | Zbl 0079.12904
[4] J.G.Stampfli, B.L.Wadhwa: On dominant operators. Monatsh. Math. 84 (1977), 143–153. DOI 10.1007/BF01579599 | MR 0458225 | Zbl 0374.47010
[5] R.E.Weber: Derivations and the trace class operators. Proc. Amer. Math. Soc. 73 (1979), 79–82. DOI 10.1090/S0002-9939-1979-0512062-0 | MR 0512062 | Zbl 0372.47019
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