Ground state solutions for nonlinear Choquard equations with doubly critical exponents

https://doi.org/10.1016/j.aml.2021.107715Get rights and content

Abstract

This paper is concerned with nonlinear Choquard equations with doubly critical growth. We apply the Pohozăev-type identity to overcome loss of compactness caused by the doubly critical nonlinearities and obtain the existence of a ground state solution.

Section snippets

Introduction and main result

In this paper, we study the existence of ground state solutions for the following Choquard equation: Δu+u=(|x|αN|u|p)|u|p2u+(|x|αN|u|q)|u|q2u,inRN,where N3, α(0,N), q=N+αN and p=N+αN2 are called as the lower and the upper critical exponents with respect to the Hardy–Littlewood–Sobolev inequality respectively. It is known that the equation Δu+u=(|x|αN|u|r)|u|r2u,inRNarises in the description of the quantum theory of a polaron at rest by Pekar in 1954 and the modeling of an electron

Proof of Theorem 1.1

In this section, we shall prove that Eq. (1.1) admits a ground state solution on M. We firstly give the following useful observation.

Lemma 2.1

The functional J is unbounded from below.

Proof

Let uX, and ut=tu(tbx), b=2αN(2+α), t>0. The standard scaling implies that J(ut)=t4q2+α2RN|u|2dx+t42+α2RN|u|2dxt4q2+α2qL1(u)t4pq2+α2pL2(u).It is easy to follow from our assumptions that J(ut) as t+. As desired. 

Lemma 2.2

Let p>q and a1,a2,a3,a4 be positive constants, and f(t)=a1t4q2+α+a2t42+αa3t4q2+αa4t4pq2+α for t0.

Acknowledgments

B. Zhang was supported by the National Natural Science Foundation of China (No. 11871199), the Shandong Provincial Natural Science Foundation, PR China (No. ZR2020MA006), and the Cultivation Project of Young and Innovative Talents in Universities of Shandong Province .

References (19)

There are more references available in the full text version of this article.
View full text