Multiple positive solutions for degenerate Kirchhoff equations with singular and Choquard nonlinearity

TL;DR

This paper investigates the existence, multiplicity, and regularity of positive solutions for a complex fractional Kirchhoff-Choquard equation with singular and critical nonlinearities, establishing boundedness, regularity, and multiple solutions.

Contribution

It introduces new results on positive solutions for degenerate Kirchhoff equations with singular and Choquard nonlinearities, including existence, multiplicity, and regularity properties.

Findings

Proved all positive weak solutions are bounded and Hölder continuous.

Established the existence of at least two positive solutions.

Analyzed the problem using variational and truncation methods.

Abstract

In this paper we study the existence, multiplicity and regularity of positive weak solutions for the following Kirchhoff-Choquard problem: \begin{equation*} \begin{array}{cc} \displaystyle M\left( \iint\limits_{\mathbb{R}^{2N}} \frac{|u(x)-u(y)|^2}{|x-y|^{N+2s}}\,dxdy\right) (-\Delta)^s u = \frac{\lambda}{u^\gamma} + \left( \int\limits_{\Omega} \frac{|u(y)|^{2^{*}_{\mu ,s}}}{|x-y|^ \mu}\, dy\right) |u|^{2^{*}_{\mu ,s}-2}u \;\text{in} \; \Omega, %\quad \quad u > 0\quad \text{in} \; \Omega, \quad \quad u = 0\quad \text{in} \; \mathbb{R}^{N}\backslash\Omega, \end{array} \end{equation*} where $\Omega$ is open bounded domain of $\mathbb{R}^{N}$ with $C^2$ boundary, $N > 2s$ and $s \in (0,1)$. $M$ models Kirchhoff-type coefficient in particular, the degenerate case where Kirchhoff coefficient M is zero at zero. $(-\Delta)^s$ is fractional Laplace operator, $\lambda > 0$ is a real parameter, $\gamma \in (0,1)$ and $2^{*}_{\mu ,s} = \frac{2N-\mu}{N-2s}$ is the critical exponent in the sense of Hardy-Littlewood-Sobolev inequality. We prove that each positive weak solution is bounded and satisfy H\"older regularity of order $s$. Furthermore, using the variational methods and truncation arguments we prove the existence of two positive solutions.