Trace formulas for TBG

Becker et al. produced a striking trace formula for the sum of fourth powers of generalized magic angles, $ θ$, for the chiral model of twisted bilayer graphene (TBG) with the exact Bistritzer--MacDonald potential: $\sum θ^{4} = 8 π/ \sqrt 3 $. The purpose of this note is to generalize this formula to a larger class of potentials satisfying the symmetries of the model.