Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A note on the BMO and Calder\'{o}n-Zygmund estimate   In this note, we give a simple proof of the pointwise BMO estimate for
Poisson's equation. Then the Calder\'{o}n-Zygmund estimate follows by the
interpolation and duality.

32
The categories of this paper are: atom-ph
33
The categories of this paper are: plasm-ph
3
The categories of this paper are: physics
13
The categories of this paper are: quant-ph
9
The categories of this paper are: nlin
15
The categories of this paper are: nucl-ex
23
The categories of this paper are: solv-int
18
The categories of this paper are: econ
20
The categories of this paper are: acc-phys
37
The categories of this paper are: supr-con
7
The categories of this paper are: hep-th
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The categories of this paper are: alg-geom
16
The categories of this paper are: stat
29
The categories of this paper are: funct-an
26
The categories of this paper are: bayes-an
34
The categories of this paper are: chem-ph