Differentiating matrix functions

Autor: Kelly Bickel
Rok vydání: 2013
Předmět:
Zdroj: Operators and Matrices. :71-90
ISSN: 1846-3886
DOI: 10.7153/oam-07-03
Popis: Multivariable, real-valued functions induce matrix-valued functions defined on the space of d-tuples of n-times-n pairwise-commuting self-adjoint matrices. We examine the geometry of this space of matrices and conclude that the best notion of differentiation of these matrix-valued functions is differentiation along curves. We prove that a C^1 real-valued function always induces a C^1 matrix function and give an explicit formula for the derivative. We also show that every real-valued C^m function defined on an open rectangle in the plane induces a matrix-valued function that can be m-times continuously differentiated along C^m curves.
20 pages
Databáze: OpenAIRE