3 papers
math-ph2018
Non-existence of ground states in the translation invariant Nelson model
Thomas Norman Dam
In this paper we consider the massless translation invariant Nelson model with ultraviolet cutoff. It is proven that the fiber operators have no ground state if there is no infrare…
math-ph2018
Asymptotics in Spin-Boson type models
Thomas Norman Dam, Jacob Schach Møller
In this paper we investigate a family of models for a qubit interacting with a bosonic field. More precisely, we find asymptotic limits of the Hamiltonian as the strength of the in…
math-ph2018
Spin-Boson type models analysed using symmetries
Thomas Norman Dam, Jacob Schach Møller
In this paper we analyse a family of models for a qubit interacting with a bosonic field. These models have a parity symmetry, which enables them to have a ground state even in som…