Chambers's formula for the graphene and the Hou model with kagome   periodicity and applications
  The aim of this article is to prove that for the graphene model like for a model considered by the physicist Hou on a kagome lattice, there exists a formula which is similar to the one obtained by Chambers for the Harper model. As an application, we propose a semi-classical analysis of the spectrum of the Hou butterfly near a flat band. 
Bernard Helffer (LM-Orsay, LMJL), Philippe Kerdelhu\'e (LM-Orsay),   Jimena Royo-Letelier (IST Austria)
math.AP