Complexity for coupled-Lindblad theories

Background: Representing non-Markovian environmental effects often involves reformulating the problem into a set of auxiliary differential equations, such as those derived from pseudomode or hierarchical equations of motion (HEOM) methods.

Question / Future Work: The developed complexity framework rigorously establishes bounds for certain sum-of-exponential representations of BCFs. A key future direction is developing a similar rigorous complexity result for the more recently introduced coupled-Lindblad pseudomode theories, which satisfy additional constraints to ensure the physicality of system dynamics.