Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Extending functions from isotropic Nikolskii-Besov spaces and their
  approximating with derivatives   The article examines isotropic Nikolskii and Besov spaces with norms defined
using $L_p$-averaged modulus of continuity of functions of appropriate order,
instead of modulus of continuity of known order for fixed-order partial
derivative functions. The author builds continuous linear mappings of such
spaces of functions defined in domains of $(1,\ldots,1)$-type (in a broad
sense) to ordinary isotropic Nikolskii and Besov spaces in $ \mathbb R^d $ that
are function extension operators, thus incurring coincidence of both kinds of
spaces in the said domains. It is established that every bounded domain in $
\mathbb R^d $ with a Lipschitzian boundary is a $(1,\ldots,1)$-type domain (in
a broad sense). The article also provides weak asymptotics of approximation
characteristics related to the problem of reconstruction of functions with
their derivatives from function values at a given number of points, the
S.B.Stechkin's problem for differential operator, and the problem of width
asymptotics for isotropic Nikolskii-Besov classes in those domains.

22
The categories of this paper are: chao-dyn
3
The categories of this paper are: physics
26
The categories of this paper are: bayes-an
25
The categories of this paper are: patt-sol
34
The categories of this paper are: chem-ph
1
The categories of this paper are: cs
31
The categories of this paper are: ao-sci
15
The categories of this paper are: nucl-ex
23
The categories of this paper are: solv-int
14
The categories of this paper are: math-ph
12
The categories of this paper are: nucl-th
19
The categories of this paper are: eess
20
The categories of this paper are: acc-phys
29
The categories of this paper are: funct-an
17
The categories of this paper are: q-fin
35
The categories of this paper are: mtrl-th