We obtain an almost complete understanding of the mean-field phase diagram of the two-
dimensional Hubbard model on a square lattice with a sizable next-nearest-neighbor …

We consider electronic systems with a spontaneously broken continuous symmetry. The
scattering vertex between electrons and Goldstone modes is calculated over the entire …

We present a SU (2) gauge theory of fluctuating magnetic order in the two-dimensional
Hubbard model. The theory is based on a fractionalization of electrons in fermionic chargons …

We reconsider derivation of Ward identities for spin stiffnesses, which determine the
nonlinear sigma model of magnetic degrees of freedom of interacting electrons in the …

Electronic fluids can display exciting dynamical properties. In particular, due to Landau
damping, the collective-mode spectrum of an electronic system with multipolar interactions is …

We present an unbiased mean-field analysis of magnetic and charge orders in the two-
dimensional Hubbard model on a square lattice, at both zero and finite temperatures …

The energy-momentum dispersion of magnons, viewed as noninteracting and infinitely long-
lived quasiparticles describing collective low-energy excitations of magnetic materials, is …

We develop a dynamical mean-field theory approach for the spiral magnetic order, changing
to a local coordinate frame with preferable spin alignment along the z axis, which can be …

We derive Ward identities for fermionic systems exhibiting a gauge symmetry that gets
globally broken. In particular, we focus on the relation that connects the gauge field …

Mye forskning har hatt til hensikt å undersøke vekselvirkningene mellom magnoner og
fononer, som utgjør fundamentale eksitasjoner i magnetisk ordnede materialer …