Coherent algebra
A coherent algebra is an algebra of complex square matrices that is closed under ordinary matrix multiplication, Schur product, transposition, and contains both the identity matrix formula_1 and the all-ones matrix formula_2. Definitions. A subspace formula_3 of formula_4 is said to be a coherent algebra of order formula_5 if: A coherent algebra formula_12 is said to be: The set formula_16 of "Schur-primitive matrices" in a coherent algebra formula_3 is defined as formula_18. Dually, the set formula_19 of "primitive matrices" in a coherent algebra formula_3 is defined as formula_21.