Calabrese, PasqualeMartín Mayor, VíctorPelissetto, AndreaVicari, Ettore2023-06-202023-06-202003-07-111539-375510.1103/PhysRevE.68.016110https://hdl.handle.net/20.500.14352/52194© 2003 The American Physical Society. This work was partly supported by MCyT (Spain), Project Nos. FPA2001-1813 and FPA2000-0956.We compute the dynamic structure factor for the three-dimensional Ising model with a purely relaxational dynamics (model A). We perform a perturbative calculation in the e expansion, at two loops in the high temperature phase and at one loop in the temperature magnetic-field plane, and a Monte Carlo simulation in the high-temperature phase. We find that the dynamic structure factor is very well approximated by its mean-field Gaussian form up to moderately large values of frequency ω and momentum k. In the region we can investigate, kξ≤5, ωϮ≤10, where ξ is the correlation length and Ϯ is the zero-momentum autocorrelation time, deviations are at most of a few percent.engjournal articlehttp://dx.doi.org/10.1103/PhysRevE.68.016110https://journals.aps.orgopen access53Dispersion-theory approachCritical-point scatteringRenormalization-groupCritical exponentsField-theoryMonte-CarloSystemsEquationStateTemperature.Física-Modelos matemáticos