  In a recent Letter [Dabelow and Reimann, Phys. Rev. Lett. 124, 120602
(2020)], a perturbative relaxation theory is applied to the Bose-Hubbard model
and compared to data from a quantum simulator experiment [Trotzky et al. Nature
Phys 8, 325 (2012)]. In this Comment, I argue that the discrepancy found is due
to the quasi-local observable measured in the experiment being affected by a
harmonic trapping potential that is unaccounted for in the analytic
calculation. I support my claim with quasi-exact numerics computed using a
parallel time-evolving block decimation algorithm (TEBD), and show that the
relaxation theory gives accurate results in the correct limit when compared to
an appropriate local observable. Finally, I note that my numerics disagree with
the t-DMRG calculations of Trotzky et al. but give better qualitative agreement
with their experimental results.
