1. CJM 2007 (vol 59 pp. 638)
|Distance from Idempotents to Nilpotents |
We give bounds on the distance from a non-zero idempotent to the set of nilpotents in the set of $n\times n$ matrices in terms of the norm of the idempotent. We construct explicit idempotents and nilpotents which achieve these distances, and determine exact distances in some special cases.
Keywords:operator, matrix, nilpotent, idempotent, projection
Categories:47A15, 47D03, 15A30