title: Role of saddles in topologically driven phase transitions: the case of the d -dimensional spherical model.
abstract: Analyzing the d -dimensional spherical model, we show that underlying saddles, defined through a map in the configuration space, play a central role in driving the phase transition. At the phase transition point the underlying saddle energy reaches its lowest value, corresponding to the trivial boundary topological singularity.
authors.affiliation: Research Center SMC INFM-CNR, c/o Università di Roma "Sapienza," I-00185, Roma, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Angelani
authors.forename: G
authors.initials: G
authors.lastname: Ruocco