## Harmonic analysis of the space BV.(English)Zbl 1044.42028

A function $$f \in L^1(\Omega)$$, $$\Omega \subset R^d$$, has bounded variation if $| f| _{\text{BV}(\Omega)} := \sup_{g\in C_c^1(\Omega, R^d), \| g\| _\infty \leq 1} \int_\Omega f\text{ div}(g) < \infty.$ The space $$\text{BV}(\Omega)$$ of such functions is a Banach space when equipped with the norm: $\| f\| _{\text{BV}(\Omega)} = \| f\| _1+| f| _{\text{BV}(\Omega)}.$ Let $$D$$ be the family of dyadic cubes in $$R^d$$. Let $$\psi \in L^2(R^d)$$ be a wavelet on $$R$$. If $$E$$ denotes the set of non-zero vertices of the unit cube in $$R^d$$, and if $$e \in E$$, then we write $$\psi^e = \psi^{e_1}(x_1)\dots \psi^{e_d}(x_d)$$. For $$Q = 2^{-j}(k+[0,1]^d) \in D$$ we define $$\psi_Q^e$$ to be the wavelet $$\psi^e$$ scaled relative to $$Q$$. Let $$\widetilde{\psi^e}$$ be the dual wavelet. For a tempered distribution $$f$$ we define $$f_Q$$ to be the vector of coefficients $$\langle f, \widetilde{\psi^e_Q} \rangle$$. The paper under review provides the answer to the question: which values of $$\gamma$$ satisfy the following inequality: $\sum_{Q \in D: | f_Q| > \epsilon | Q| ^\gamma} | Q| ^\gamma \leq C \epsilon^{-1} | f| _{\text{BV}(\Omega)}?$ Applications of the characterization of all such $$\gamma$$’s include almost characterizations of $$\text{BV}$$ spaces, Gagliardo-Nirenberg-type inequalities and interpolation spaces between BV and Sobolev or Besov spaces.

### MSC:

 42C40 Nontrigonometric harmonic analysis involving wavelets and other special systems 46B70 Interpolation between normed linear spaces 26B35 Special properties of functions of several variables, Hölder conditions, etc. 42B25 Maximal functions, Littlewood-Paley theory 46E35 Sobolev spaces and other spaces of “smooth” functions, embedding theorems, trace theorems
Full Text:

### References:

  Bergh, J. and Löfström, J.: Interpolation spaces. Springer Verlag, 1976. · Zbl 0344.46071  Cohen, A.: Wavelet methods in numerical analysis, in the Handbook of Numerical Analysis, vol. VII, P.-G. Ciarlet et J.-L. Lions eds., Elsevier, Amsterdam, 2000. · Zbl 0976.65124  Cohen, A., DeVore, R. and Hochmuth, R.: Restricted Nonlinear Approximation. Constructive Approximation 16 (2000), 85-113. · Zbl 0947.41006  Cohen, A., DeVore, R., Petrushev, P. and Xu, H.: Non linear approximation and the space BV (R2). Amer. J. Math. 121 (1999), 587-628. · Zbl 0931.41019  Cohen, A., Meyer, Y. and Oru, F.: Improved Sobolev inequalities. Proceedings séminaires X-EDP, Ecole Polytechnique, Palaiseau, 1998. · Zbl 1069.46503  Dahmen, W.: Wavelet and multiscale methods for operator equations. Acta Numerica 6, Cambridge University Press, 1997, 55-228. · Zbl 0884.65106  Daubechies, I.: Ten Lectures on Wavelets. SIAM, 1992. · Zbl 0776.42018  Donoho, D., Vetterli, M., DeVore, R. and Daubechies, I.: Har- monic analysis and signal processing. IEEE Trans. Inf. Theory 44 (1998), 2435-2476. · Zbl 1125.94311  DeVore, R.: Nonlinear Approximation. Acta Numerica 7, Cambridge University Press, 1998, 51-150. · Zbl 0931.65007  DeVore, R. and Petrova, G.: The averaging lemma. J. Amer. Math. Soc. 14 (2000), 279-296. · Zbl 1001.35079  Donoho, D.: Unconditional bases are optimal for data compression and statistical estimation. Appl. Comp. Harm. Anal. 1 (1993), 100-105. · Zbl 0796.62083  Evans, L. and Gariepy, R.: Measure theory and fine properties of func- tions. CRC Press, New York, 1992. · Zbl 0804.28001  Meyer, Y.: Ondelettes et Opérateurs. Hermann, Paris, 1990.  Ziemer, W.: Weakly differentiable functions. Springer Verlag, New York, 1989. · Zbl 0692.46022
This reference list is based on information provided by the publisher or from digital mathematics libraries. Its items are heuristically matched to zbMATH identifiers and may contain data conversion errors. It attempts to reflect the references listed in the original paper as accurately as possible without claiming the completeness or perfect precision of the matching.