Aging in ferromagnetic systems at criticality: field-theoretical approach
Andrea Gambassi


Abstract
We study the non-equilibrium rensponse and correlation functions and the corresponding fluctuation-dissipation ratio for a purely relaxational dynamics of the O(N) vector model (Model A), below its upper critical dimension. The scaling behaviour of these quantities is analyzed and the associated universal functions are determined up to the second order in the epsilon-expansion. A non trivial limit of the fluctuation-dissipation ratio is found in the aging regime. We also briefly discuss the result of similar computation for the Random Ising Model and for the Model C dynamics. We compare our results with the scaling form for the critical response function, recently predicted assuming local scale invariance.

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Elenco dei partecipanti al convegno di Bari.

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