The isometries of certain maximum norms Original Research Article

Let A1, … , Am be nonsingular n × n matrices over image or image, and let 1 less-than-or-equals, slant pj less-than-or-equals, slant ∞ for j = 1, … , m. We characterize the linear isometries for the norm N on image defined byimagewhere lp(y) denotes the lp-norm of image. As an application we study the conditions on matrices A1, … , Am for which N is absolute or a symmetric gauge function.