Linearization stability theorem (source code)

= Linearization stability theorem

If every Jacobian eigenvalue has negative real part, the equilibrium is locally asymptotically stable.

More generally, if the <equilibrium> is hyperbolic, the <Hartman-Grobman theorem> transfers the local attracting, repelling or saddle behavior of the linearized <vector field> to the nonlinear flow. Two real <eigenvalues> with opposite signs give a <saddle equilibrium>; all real parts positive give a source. Purely imaginary or zero <eigenvalues> require a separate nonlinear analysis. Merely having distinct <eigenvalues> does not remove this exception.