3 papers
math.AP2026
The "good" Boussinesq equation on the half-line: a Riemann-Hilbert approach
Christophe Charlier, Jonatan Lenells
We consider the ``good" Boussinesq equation on the half-line. Assuming existence of the solution, we prove that it can be recovered from the solution of a Riemann-Hilbe…
math-ph2025
On the Hartree-Fock phase diagram for the two-dimensional Hubbard model
Christophe Charlier, Edwin Langmann, Jonatan Lenells
We propose an analytical method for the construction of Hartree-Fock phase diagrams for the (fermion) Hubbard model and various generalizations thereof. Such phase diagrams are tra…
cond-mat.quant-gas2025
Mixed phases in a Fermi--Hubbard model describing altermagnetism
E. Langmann, J. Lenells
We study an extension of the 2D Fermi--Hubbard model, which was recently introduced in [Das et al., Phys. Rev. Lett. 132, 263402 (2024)] and shown to describe altermagnetism that c…