On the recognition and rigidity problems for sums of matrices Original Research Article

Let S0,…,Sk be k+1 similarity classes of matrices over an algebraically closed field. This paper gives partial answers to the problems of existence (recognition) and uniqueness modulo simultaneous similarity (rigidity) of the solutions of the equation Ak=A0+cdots, three dots, centered+Ak−1, with Aiset membership, variantSi, 0less-than-or-equals, slantiless-than-or-equals, slantk.