Singular matrices that are products of two idempotents or products of two nilpotents

Abstract

Over commutative domains we characterize the singular 2 × 2 matrices which are products of two idempotents or products of two nilpotents. The relevant casees are the matrices with zero second row and the singular matrices with only nonzero entries.

Keywords

• idempotent matrix
• nilpotent matrix
• quadratic diophantine equation
• 2 × 2 matrix
• 15b33
• 15b99
• 11d09
• 11t99