Continuous symmetries of characteristic equations and their associated evolution equations
Carl E. Wulfman · AIP conference proceedings · 1992
Continuous variations of the elements of an N×N matrix which leave invariant its eigenvalues leave invariant its associated evolution equation and determine GL(N) symmetry groups acting in the space {M}×{V} of continuously variable matrix elements M and vectors V.All the variations in {V} that are not simple dilatations are out of phase with those in {M}. A phase analogous to that introduced into physics by M. V. Berry appears as a general property of linear systems representable in {M}×{V} by characteristic equations or their associated evolution equations.