  We investigate the electronic properties of corrugated graphene and show how
rippling-induced pseudomagnetic fields alter graphene's low-energy electronic
properties by combining first principles calculations with an effective field
theory. The formation of flat bands near the Fermi level corresponding to
pseudo-Landau levels is studied as a function of the rippling parameters.
Quenched and relaxed ripples turn out to be fundamentally different is this
respect: It is demonstrated, both numerically and analytically, that annealing
of quenched ripples can destroy the flat bands.
