17,198 research outputs found

    Test of Local Scale Invariance from the direct measurement of the response function in the Ising model quenched to and to below TCT_C

    Full text link
    In order to check on a recent suggestion that local scale invariance [M.Henkel et al. Phys.Rev.Lett. {\bf 87}, 265701 (2001)] might hold when the dynamics is of Gaussian nature, we have carried out the measurement of the response function in the kinetic Ising model with Glauber dynamics quenched to TCT_C in d=4d=4, where Gaussian behavior is expected to apply, and in the two other cases of the d=2d=2 model quenched to TCT_C and to below TCT_C, where instead deviations from Gaussian behavior are expected to appear. We find that in the d=4d=4 case there is an excellent agreement between the numerical data, the local scale invariance prediction and the analytical Gaussian approximation. No logarithmic corrections are numerically detected. Conversely, in the d=2d=2 cases, both in the quench to TCT_C and to below TCT_C, sizable deviations of the local scale invariance behavior from the numerical data are observed. These results do support the idea that local scale invariance might miss to capture the non Gaussian features of the dynamics. The considerable precision needed for the comparison has been achieved through the use of a fast new algorithm for the measurement of the response function without applying the external field. From these high quality data we obtain a=0.27±0.002a=0.27 \pm 0.002 for the scaling exponent of the response function in the d=2d=2 Ising model quenched to below TCT_C, in agreement with previous results.Comment: 24 pages, 6 figures. Resubmitted version with improved discussions and figure

    14-bit 2.2-MS/s sigma-delta ADC's

    Get PDF
    • …
    corecore