International Workshop “Infinite and Finite Nuclear Matter” (INFINUM-2025)

Spectral functions of the $O(N)$ model from the functional renormalization group approach

Not scheduled

20m

Blokhintsev hall (4th floor) (BLTP)

Speaker

Dr Nikita Lebedev (N.N. Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research)

Description

We will discuss the computation of spectral functions of bound states using the real-time formulation of a functional renormalization group (FRG) approach on the example of the O(4) model. The computation is based on the Kallen-Lehmann spectral representation of dressed propagators used in the Wetterich equation -- the flow equation of the effective action. We consider an approximation of momentum-independent vertices, the so called propagator approximation. Such an approach gives analytic access to the emergent singularities and brunch cuts, which opens the way for the numerical solution of a system of the FRG equations for the spectral functions corresponding to dressed retarded propagators.