The Hubbard model represents the fundamental model for interacting quantum systems and
electronic correlations. Using the two-dimensional half-filled Hubbard model at weak …

Precise calculations of dynamics in the homogeneous electron gas (jellium model) are of
fundamental importance for design and characterization of new materials. We introduce a …

We investigate the momentum-resolved spin and charge susceptibilities, as well as the
chemical potential and double occupancy in the two-dimensional Hubbard model as …

We present a generalization of the discrete Lehmann representation (DLR) to three-point
correlation and vertex functions in imaginary time and Matsubara frequency. The …

The study of warm dense matter, widely existing in nature and laboratories, is challenging
due to the interplay of quantum and classical fluctuations. We develop a variational …

High-temperature bad-metal transport has been recently studied both theoretically and in
experiments as one of the key signatures of strong electronic correlations. Here we use 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 …

We systematically generate the perturbative expansion for the two-particle spin susceptibility
in the Feynman diagrammatic formalism and apply this expansion to a model system—the …

Conceptually, the Matsubara formalism (MF), using imaginary frequencies, and the Keldysh
formalism (KF), formulated in real frequencies, give equivalent results for systems in thermal …

Recent experiments on cold atoms in optical lattices allow for a quantitative comparison of
the measurements to the conductivity calculations in the square lattice Hubbard model …