ELA, Volume 16, pp. 237-247, September 2007, abstract.
Products of Commuting Nilpotent Operators
Damjana Kokol Bukovsek, Tomaz Kosir, Nika Novak, and
Polona Oblak
Matrices that are products of two (or more) commuting
square-zero matrices and matrices that are products of
two commuting nilpotent matrices are characterized. Also
given are characterizations of operators on an infinite
dimensional Hilbert space that are products of two (or more)
commuting square-zero operators, as well as operators on an
infinite-dimensional vector space that are products of two
commuting nilpotent operators.