The Schwarz Normal Form of a Matrix and Its Application to Flutter Stability Problems (Ein Verfahren zur Stabilitatsfrage bei Matrizen-Eigenwert Problem),
Schwarz,Hans-Rudolf · Defense Technical Information Center (DTIC) · 1973
Given the Eigenvalue problem (A - lambda E)x = 0 for a real or complex matrix A, the number of Eigenvalues lambda with positive real parts is determined without evaluating the characteristic polynomial. A procedure is developed to transform the given matrix A to a canonical form by means of a finite series of elementary transformations of the matrix. The elements of the reduced matrix allow one to solve immediately the stability problem. (Author)