Multiple solutions for some Neumann problems in exterior domains

Tsing-San Hsu, Huei-Li Lin
2006 Bulletin of the Australian Mathematical Society  
In this paper, we show that if q(x) satisfies suitable conditions, then the Neumann problem -Au+u = g(a:)|w| p~2 u in fi has at least two solutions of which one is positive and the other changes sign.
doi:10.1017/s0004972700035395 fatcat:rfskcilokndwtclmk2ant7o7wi