# Mathematics Colloquia and Seminars

We consider the translation-invariant system in R^3 consisting of a freely propagating, non-relativistic, charged particle that interacts with the quantized, ultraviolet regularized electromagnetic field. By use of the operator-theoretic renormalization group method due to Bach, Froehlich and Sigal, we construct the infraparticle state for an associated infrared regularized model at fixed conserved total momentum $p$, which converges to an element of some non-Fock infrared representation Hilbert space under removal of the infrared regularization. Moreover, we prove bounds on the renormalized effective mass of the infraparticle that are uniform with respect to the infrared regularization. All of these results hold for sufficiently small values of |p| and the coupling constant g.