(3:30~4:00pm, Tea, Coffee, and Cookie)
In this talk we review our recent work on quantum impurities. In particular I will focus
on the Bose polaron, an impurity strongly interacting with a Bose-Einstein condensate.
In our work we make predictions for the Bose polaron's spectral function and its
various quasiparticle properties using a field-theoretic approach that can be tested in
experiment. We find that most of the spectral weight is contained in a coherent
attractive and a metastable repulsive polaron branch. Additionally we show that the
qualitative behavior of the Bose polaron is well described by a non-selfconsistent Tmatrix
approximation by comparing analytical results to numerical data obtained from
a fully self-consistent T-matrix approach. The latter takes into account an infinite
number of bosons excited from the condensate. Also we discuss how our results can be
tested in experiment using radio frequency spectroscopy. Finally we comment on the
implications of our results for an attempted quantum simulation of the Froehlich
Hamiltonian using ultracold atoms.