In this talk I will present some recent progress on the construction of ground state of the two-dimensional Hubbard model, which is a prototypical model for studying phase transitions in quantum many-body systems. Using fermionic cluster expansions and constructive renormalization theory, we proved that the ground state of the 2-d Hubbard model on the honeycomb lattice with triangular Fermi surfaces is not a Fermi liquid in a mathematical precise sense (Salmhofer criterium). I will also discuss the crossover phenomenon in the 2D square lattice Hubbard model and universality. This presentation is based on the work CMP 401, 2569–2642(2023) and arXiv:2303.13628.

Via Teams al seguente Link
org: GIULIANI Alessandro