| Affiliation: | (1) Department of Mathematics, Texas A&M University, 77843 College Station, TX, USA;(2) Department of Mathematics, College of Natural Science, Kyungpook National University, 702-701 Daegu, Korea;(3) Department of Mathematics, Ewha Women’s University, 120-750 Seoul, Korea;(4) Department of Mathematics, Texas A&M University, 77843 College Station, TX, USA |
| Abstract: | We consider the question of which operators on Hilbert space admit a moment sequence, and show, in particular, that ifT is any operator inL(itH) that can be written asT=N+K, whereN is normal andK is compact, andM⊂itH is any invariant subspace forT, then the restrictionT/itM admits such a sequence. |
