Structural and cooperative length scales in polymer gels Baudouin Géraud, Loren Jørgensen, Christophe Ybert, Hélène Delanoë-Ayari and Catherine Barentin Eur. Phys. J. E, 40 1 (2017) 5 Published online: 19 January 2017 DOI: 10.1140/epje/i2017-11490-y