Instantons and the〈A2〉condensate

We argue that the $〈A_{\mathrm{OPE}}^2〉$ condensate found in the Landau gauge on lattices, when an operator product expansion of Green’s functions is performed, might be explained by instantons. We use cooling to estimate the instanton contribution and extrapolate back the result to the thermalized configuration. The resulting $〈A_{\mathrm{inst}}^2〉$ is similar to $〈A_{\mathrm{OPE}}^2〉.$