Norms and derivatives
type: Item
instance of: scholarly article
title: Norms and derivatives
zbMATH Open document ID: 0787.26009
author: Jan Mařík
published in: Real Analysis Exchange
publication date: 1993-12-15T00:00:00Z
review text: The paper is a continuation of \textit{J. Mařík} and \textit{C. E. Weil} [Proc. Am. Math. Soc. 112, No. 3, 807-817 (1991; Zbl 0746.26002)]. The aim is to study conditions under which the square root of the sum of squares of two derivatives is still a derivative. The conditions are formulated in terms of multiplicative families for bounded approximately continuous functions and stated in Theorem 6.2 (even in greater generality for \(p>0\)). The paper includes also some negative results and generalizations for \(n\)-tuples of derivatives.
Mathematics Subject Classification ID: 26A24
Mathematics Subject Classification ID: 26A15
zbMATH DE Number: 465094
zbMATH Keywords: sums of powers of derivatives
zbMATH Keywords: square root
zbMATH Keywords: sum of squares of two derivatives
zbMATH Keywords: multiplicative families
zbMATH Keywords: bounded approximately continuous functions
reviewed by: Jerzy Niewiarowski
MaRDI profile type: Publication
description: scientific article; zbMATH DE number 465094