Spectral properties of non-selfadjoint extensions of the Calogero Hamiltonian (Q2816493)

This paper studies spectral properties of the Calogero Hamiltonian \(L=-d/dr^2+b/r^2\) for \(b<-1/4\). This Hamiltonian has been studied previously for the case of \(b\geq-1/4\), where some selfadjoint and nonnegative properties are preserved, even in the \(N\)-dimensional case. The authors characterize all intermediate operators between \(L_{min}\) and \(L_{max}\) with non-empty resolvent set and describe their spectrum. They also give some partial results in the \(N\)-dimensional case.