7 papers
Dynamics and equilibrium states of infinite systems of lattice bosons
Andreas Deuchert, Jonas Lampart, Marius Lemm
We consider the dynamics of systems of lattice bosons with infinitely many degrees of freedom. We show that their dynamics defines a group of automorphisms on a --algebra intr…
Effective Dynamics for the Bose Polaron in the Large-Volume Mean-Field Limit
Jonas Lampart, Peter Pickl, Siegfried Spruck
We consider the dynamics of the Bose polaron system, a dense quantum gas consisting of bosons evolving in in the presence of an impurity particle. The system is…
Validity of the Fröhlich model for a mobile impurity in a Bose-Einstein condensate
Jonas Lampart, Arnaud Triay
We analyze the many-body Hamiltonian describing a mobile impurity immersed in a Bose-Einstein condensate (BEC). Using exact unitary transformations and rigorous error estimates, we…
A numerical study of stability for solitary waves of a quasi-linear Schr{ö}dinger equation
Meriem Bahhi, Jonas Lampart, Christian Klein +1
We discuss the (in)stability of solitary waves for a quasi-linear Schr{ö}dinger equation. The equation contains a quasi-linear term, responsible for a saturation effect, as well a…
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…