## On the existence of positive solutions for semilinear elliptic equations in the annulus.(English)Zbl 0798.34030

The existence of positive radial solutions of $$\Delta u + g (| x |) f(u)=0$$ in annuli with Dirichlet (Dirichlet/Neumann) boundary conditions is proved. It is shown that the problem has positive radial solution on any annulus if $$f$$ is sublinear at 0 and $$\infty$$.
Reviewer: P.Drábek (Plzeň)

### MSC:

 34B15 Nonlinear boundary value problems for ordinary differential equations 35J15 Second-order elliptic equations
Full Text: