We argue that the <AOPE2> condensate found in the Landau gauge on lattices, when an Operator Product Expansion of Green functions is performed, might be explained by instantons. We use cooling to estimate the instanton contribution and extrapolate back the result to the thermalised configuration. The resulting <Ainst2> is similar to <AOPE2>.
@article{arxiv.hep-ph/0203119,
title = {Instantons and $<A^2>$ Condensate},
author = {Ph. Boucaud and J. P. Leroy and A. Le Yaouanc and J. Micheli and O. Pène and F. De Soto and A. Donini and H. Moutarde and J. Rodríguez-Quintero},
journal= {arXiv preprint arXiv:hep-ph/0203119},
year = {2010}
}