Sum of squares of derivable functions

被引：11

作者：

Bony, Jean-Michel ^{[1
]}

机构：

[1] Ecole Polytech, Ctr Math, F-91128 Palaiseau, France

来源：

BULLETIN DE LA SOCIETE MATHEMATIQUE DE FRANCE | 2005年 / 133卷 / 04期

关键词：

D O I：

10.24033/bsmf.2499

中图分类号：

O1 [数学];

学科分类号：

0701 ; 070101 ;

摘要：

We prove that any nonnegative function of class C-2m defined in an interval is the sum of two squares of functions of class C-m. In dimension 2, any nonnegative function f of class C-4 is a finite sum of squares of functions of class C-2, provided that del(4)f vanishes at points x satisfying f(x) = del(2)f(x) = 0.

引用

页码：619 / 639

页数：21

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