From the stress response function (back) to the sand pile “dip” A. P. F. Atman, P. Brunet, J. Geng, G. Reydellet, P. Claudin, R. P. Behringer and E. Clément Eur. Phys. J. E, 17 1 (2005) 93-100 Published online: 06 April 2005 DOI: 10.1140/epje/i2005-10002-2