BIB-VERSION:: CS-TR-v2.0 ID:: STAN//CS-TR-65-28 ENTRY:: January 19, 1996 ORGANIZATION:: Stanford University, Department of Computer Science TITLE:: Matrix theorems for partial differential and difference equations TYPE:: Technical Report AUTHOR:: Miller, John J. H. AUTHOR:: Strang, Gilbert DATE:: July 1965 PAGES:: 36 ABSTRACT:: We extend the work of Kreiss and Morton to prove: for some constant K(m), where m is the order of the matrix A, $|A^(n)v| \leq C(v)$ for all n $geq$ 0 and |v| = 1 implies that $|{SAS}^{-1}| \leq 1$ for some S with $|S^{-1}| \leq 1$, |Sv| $\leq$ k(m)C(v). We establish the analogue for exponentials $e^{Pt}$, and use it to construct the minimal Hilbert norm dominating $L_2$ in which a given partial differential equation with constant coefficients is well-posed. NOTES:: [Adminitrivia V1/Prg/19960119] END:: STAN//CS-TR-65-28