Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Generalized fractional maximal functions in Lorentz spaces   In this paper we give the complete characterization of the boundedness of the
generalized fractional maximal operator $$
  M_{\phi,\Lambda^{\alpha}(b)}f(x) : = \sup_{Q \ni x} \frac{\|f
\chi_Q\|_{\Lambda^{\alpha}(b)}}{\phi (|Q|)} \qquad (x \in {\mathbb R}^n), $$
between the classical Lorentz spaces $\Lambda^p (v)$ and $\Lambda^q(w)$ for
appropriate functions $\phi$, where $0 < p,\,q < \infty$, $0 < \alpha \le r <
\infty$, $v,w,\,b$ are weight functions on $(0,\infty)$ such that $0 < B(x): =
\int_0^x b < \infty$, $x > 0$, $B \in \Delta_2$ and $B(t) / t^{\alpha / r}$ is
quasi-increasing.

32
The categories of this paper are: atom-ph
22
The categories of this paper are: chao-dyn
26
The categories of this paper are: bayes-an
11
The categories of this paper are: hep-lat
27
The categories of this paper are: comp-gas
9
The categories of this paper are: nlin
36
The categories of this paper are: cmp-lg
3
The categories of this paper are: physics
6
The categories of this paper are: astro-ph
16
The categories of this paper are: stat
37
The categories of this paper are: supr-con
14
The categories of this paper are: math-ph
25
The categories of this paper are: patt-sol
13
The categories of this paper are: quant-ph
20
The categories of this paper are: acc-phys
18
The categories of this paper are: econ