An Axiomatic Approach to Function Spaces, Spectral Synthesis, and Luzin Approximation

Download or read book An Axiomatic Approach to Function Spaces, Spectral Synthesis, and Luzin Approximation written by Lars Inge Hedberg and published by American Mathematical Soc.. This book was released on 2007 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors define axiomatically a large class of function (or distribution) spaces on $N$-dimensional Euclidean space. The crucial property postulated is the validity of a vector-valued maximal inequality of Fefferman-Stein type. The scales of Besov spaces ($B$-spaces) and Lizorkin-Triebel spaces ($F$-spaces), and as a consequence also Sobolev spaces, and Bessel potential spaces, are included as special cases. The main results of Chapter 1 characterize our spaces by means of local approximations, higher differences, and atomic representations. In Chapters 2 and 3 these results are applied to prove pointwise differentiability outside exceptional sets of zero capacity, an approximation property known as spectral synthesis, a generalization of Whitney's ideal theorem, and approximation theorems of Luzin (Lusin) type.