On radial positive normalized solutions of the Nonlinear Schrödinger equation in an annulus

We are interested in the following semilinear elliptic problem:

$$\begin{aligned} {\left\{ \begin{array}{ll} -\Delta u + \lambda u = u^{p-1}, x \in T, \\ u > 0, u = 0 \ \text {on} \ \partial T, \\ \int _{T}u^{2} \, dx= c \end{array}\right. } \end{aligned}$$

where \(T = \{x \in \mathbb {R}^{N}: 1< |x| < 2\}\) is an annulus in \(\mathbb {R}^{N}\), \(N \ge 2\), \(p > 1\) is Sobolev-subcritical, searching for conditions (about c, N and p) for the existence of positive radial solutions. We analyze the asymptotic behavior of c as \(\lambda \rightarrow +\infty \) and \(\lambda \rightarrow -\lambda _1\) to get the existence, non-existence and multiplicity of normalized solutions. Additionally, based on the properties of these solutions, we extend the results obtained in Pierotti et al. in Calc Var Partial Differ Equ 56:1–27, 2017. In contrast of the earlier results, a positive radial solution with arbitrarily large mass can be obtained when \(N \ge 3\) or if \(N = 2\) and \(p < 6\). Our paper also includes the demonstration of orbital stability/instability results.