KTH/Nordita/SU seminar in Theoretical Physics

Threshold Singularities in the 1D Hubbard Model

by Fabian Essler (Oxford University)

Europe/Stockholm
FA32 (OBS!)

FA32 (OBS!)

Description
I consider the single-particle spectral function of the one dimensional Hubbard model below half-filling. For fixed momentum the spectral function exhibits kinematic thresholds as a function of energy. Above these thresholds the spectral function exhibits power-law singularities. I determine the threshold exponent, which is momentum dependent and differs from the Luttinger liquid prediction. The difference arises from irrelevant perturbations to the low-energy Luttinger liquid description.