The coefficient matrix must be positive to ensure that the equation is trace-preserving and completely positive.
Schrödinger equation | Nernst equation | Monge–Ampère equation | Boltzmann equation | Diophantine equation | Göran Lindblad | Ordinary differential equation | ordinary differential equation | Young–Laplace equation | Wave equation | wave equation | Vlasov equation | Tait equation | Smoluchowski coagulation equation | Sauerbrey equation | Rune Lindblad | Redlich–Kwong equation of state | Ramanujan–Nagell equation | Quadratic equation | Prony equation | Pell's equation | Mathieu's equation | Marchenko equation | Majorana's equation | Linear equation | linear equation | Liénard equation | Lars-Eric Lindblad | Kepler's equation | Kaup–Kupershmidt equation |