Jacob Schach Moeller
On the essential spectrum of the translation invariant Nelson model
(357K, pdf)

ABSTRACT.  Let $\RR^\nu\ni\xi\to\Sess(\xi)$ denote the bottom of the 
essential spectrum for the fiber Hamiltonians of the translation 
invariant massive Nelson model, which describes a 
$\nu$-dimensional electron linearly coupled to a scalar massive 
radiation field. We prove that, away from a locally finite set, 
$\Sess$ is an analytic function of total momentum.