It's probably not as complicated as it is being made to sound. I don't know about the "quasis" but it sounds like a linear algebra problem. Hyperbolic might be

It's probably not as complicated as it is being made to sound. I don't know about the "quasis" but it sounds like a linear algebra problem. Hyperbolic might be the form of the solutions to each of the differential equations, or of their combined solution. "Lorentzian metric" presumably means the usual Minkowski space of relativity.