Before revision:  In a recent study \mbox{%DIFAUXCMD DBB , it was proposed to revert this point of view and consider simulations as made of dozens of sequences of eigenvalue problems; each sequence groups together eigenproblems with equal k -vectors and an increasing outer-iteration cycle index \ell.
After revision:  In a recent study \mbox{%DIFAUXCMD DBB , it was  k -vectors and an increasing outer-iteration cycle index \ell.