Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Multiple Positive Solutions for Nonlocal Elliptic Problems Involving the
  Hardy Potential and Concave-Convex Nonlinearities   In this paper, we study the existence and multiplicity of solutions for the
following fractional problem involving the Hardy potential and concave-convex
nonlinearities: $$({-}{ \Delta})^{\frac{\alpha}{2}}u- \gamma
\frac{u}{|x|^{\alpha}}= \lambda f(x) |u|^{q - 2} u + g(x)
{\frac{|u|^{p-2}u}{|x|^s}} \ \text{ in } {\Omega,} \quad \text{ with Dirichlet
boundary condition } u = 0 \ \text{ in } \mathbb{R}^n \setminus \Omega,$$ where
$\Omega \subset \mathbb{R}^n$ is a smooth bounded domain in $\mathbb{R}^n$
containing $0$ in its interior, and $f,g \in C(\overline{\Omega})$ with
$f^+,g^+ \not\equiv 0$ which may change sign in $\overline{\Omega}.$ We use the
variational methods and the Nehari manifold decomposition to prove that this
problem has at least two positive solutions for $\lambda$ sufficiently small.
The variational approach requires that $0 < \alpha <2,$ $ 0 <s < \alpha <n,$ $
1<q<2<p \le 2_{\alpha}^*(s):= \frac{2(n-s)}{n-\alpha},$ and $ \gamma <
\gamma_H(\alpha) ,$ the latter being the best fractional Hardy constant on
$\mathbb{R}^n.$

31
The categories of this paper are: ao-sci
23
The categories of this paper are: solv-int
37
The categories of this paper are: supr-con
15
The categories of this paper are: nucl-ex
24
The categories of this paper are: dg-ga
25
The categories of this paper are: patt-sol
0
The categories of this paper are: hep-ph
10
The categories of this paper are: q-bio
7
The categories of this paper are: hep-th
34
The categories of this paper are: chem-ph
9
The categories of this paper are: nlin
1
The categories of this paper are: cs
11
The categories of this paper are: hep-lat
21
The categories of this paper are: adap-org
4
The categories of this paper are: cond-mat
3
The categories of this paper are: physics