Is there an analytic expression for
$$ \int_{0}^{\infty} e^{-At}e^{-Bt} dt $$ where $A$ and $B$ are non-commuting matrices?
Is there an analytic expression for
$$ \int_{0}^{\infty} e^{-At}e^{-Bt} dt $$ where $A$ and $B$ are non-commuting matrices?
There is no general analytic expression. However, the integral (when it exists) satisfies Sylvester's equation, $$ AX + XB = \text{Id}, $$ and can be computed using specialized algorithms, such as the Bartels–Stewart algorithm.
Surprisingly, neither of these links mentions the connection to exponential integrals.