Roth's solvability criteria for the matrix equations $AX-\hat{X}B=C$ and $X-A\hat{X}B=C$ over the skew field of quaternions with an involutive automorphism $q\mapsto \hat{q}$

Vyacheslav Futorny, Tetiana Klymchuk, Vladimir V. Sergeichuk

The matrix equation $AX-XB=C$ has a solution if and only if the matrices [A&C\\0&B] and [A &0\\0 & B] are similar. This criterion was proved over a field by W.E. Roth (1952) and ov…