5 papers
A Feynman-Kac Formula for the Subcritical Ultraviolet-Renormalized Spin Boson Model
Daniel M. Fröhlich, Benjamin Hinrichs
We prove a Feynman-Kac formula (FKF) for the self-energy renormalized spin boson Hamiltonian, describing a two-state quantum system linearly coupled to a bosonic quantum field. Sim…
Wiener-Type Theorems for the Laplace Transform. With Applications to Ground State Problems
Benjamin Hinrichs, Steffen Polzer
We study the behavior of a probability measure near the bottom of its support in terms of time averaged quotients of its Laplace transform. We discuss how our results are connected…
Ultraviolet Renormalization of Spin Boson Models I. Normal and 2-Nilpotent Interactions
Benjamin Hinrichs, Jonas Lampart, Javier ValentÃn MartÃn
We study the ultraviolet problem for models of a finite-dimensional quantum mechanical system linearly coupled to a bosonic quantum field, such as the (many-)spin boson model or it…
A Lower Bound on the Critical Momentum of an Impurity in a Bose-Einstein Condensate
Benjamin Hinrichs, Jonas Lampart
In the Bogoliubov-Fröhlich model, we prove that an impurity immersed in a Bose-Einstein condensate forms a stable quasi-particle when the total momentum is less than its mass time…
On the Ising Phase Transition in the Infrared-Divergent Spin Boson Model
Volker Betz, Benjamin Hinrichs, Mino Nicola Kraft +1
We prove absence of ground states in the infrared-divergent spin boson model at large coupling. Our key argument reduces the proof to verifying long range order in the dual one-dim…