In the 0+ 1-dimensional imaginary-time path integral formulation of quantum impurity
problems, the retarded action encodes the hybridization of the impurity with the bath. In this …

The crossover from fluctuating atomic constituents to a collective state as one lowers
temperature or energy is at the heart of the dynamical mean-field theory description of the …

A major challenge in the field of correlated electrons is the computation of dynamical
correlation functions. For comparisons with experiment, one is interested in their real …

Hund metals are multi-orbital systems with moderate Coulomb interaction, U, among
charges and sizeable Hund's rule coupling, J (< U), that aligns the spins in different orbitals …

The localization-delocalization transition is at the heart of strong correlation physics.
Recently, there is great interest in multiorbital systems where this transition can be restricted …

An emergent and promising tensor-network-based impurity solver is to represent the
Feynman-Vernon influence functional as a matrix product state, where the bath is integrated …

The path integral formalism is the building block of many powerful numerical methods for
quantum impurity problems. However, existing fermionic path integral-based numerical …

Multipoint vertex functions, and the four-point vertex in particular, are crucial ingredients in
many-body theory. Recent years have seen significant algorithmic progress toward …

The many-body problem is usually approached from one of two perspectives: the first
originates from an action and is based on Feynman diagrams, the second is centered …

Non-Abelian anyons are fractional excitations of gapped topological models believed to
describe certain topological superconductors or quantum Hall states. Here, we provide the …