Gaussian free field in the background of correlated random clusters, formed by metallic nanoparticles Jafar Cheraghalizadeh, Morteza N. Najafi and Hossein Mohammadzadeh Eur. Phys. J. B, 91 5 (2018) 81 Published online: 07 May 2018 DOI: 10.1140/epjb/e2018-90086-8