title: Critical structure factors of bilinear fields in O(N) vector models.
abstract: We compute the two-point correlation functions of general quadratic operators in the high-temperature phase of the three-dimensional O(N) vector model by using field-theoretical methods. In particular, we study the small- and large-momentum behavior of the corresponding scaling functions, and give general interpolation formulas based on a dispersive approach. Moreover, we determine the crossover exponent phi(T) associated with the traceless tensorial quadratic field, by computing and analyzing its six-loop perturbative expansion in fixed dimension. We find phi(T)=1.184(12), phi(T)=1.271(21), and phi(T)=1.40(4) for N=2,3,5, respectively.
authors: Scuola Normale Superiore and INFN, Sezione di Pisa, I-56100 Pisa, Italy. Pasquale.Calabrese@df.unipi.it
authors: Pasquale
authors: P
authors: Calabrese
authors: Andrea
authors: A
authors: Pelissetto
authors: Ettore
authors: E
authors: Vicari