Mirón Granese Nahuel, Kandus Alejandra, Calzetta Esteban
Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Rivadavia 1917, Ciudad de Buenos Aires CP 1033, Argentina.
Facultad de Ciencias Astronómicas y Geofísicas, Universidad Nacional de La Plata, Paseo del Bosque, La Plata CP 1900, Argentina.
Entropy (Basel). 2022 Dec 7;24(12):1790. doi: 10.3390/e24121790.
Just as non-relativistic fluids, oftentimes we find relativistic fluids in situations where random fluctuations cannot be ignored, with thermal and turbulent fluctuations being the most relevant examples. Because of the theory's inherent nonlinearity, fluctuations induce deep and complex changes in the dynamics of the system. The Martin-Siggia-Rose technique is a powerful tool that allows us to translate the original hydrodynamic problem into a quantum field theory one, thus taking advantage of the progress in the treatment of quantum fields out of equilibrium. To demonstrate this technique, we shall consider the thermal fluctuations of the spin two modes of a relativistic fluid, in a theory where hydrodynamics is derived by taking moments of the Boltzmann equation under the relaxation time approximation.
正如非相对论流体一样，我们常常会在随机涨落不可忽略的情形中发现相对论流体，热涨落和湍流涨落就是最典型的例子。由于该理论固有的非线性，涨落在系统动力学中会引发深刻而复杂的变化。马丁 - 西格西亚 - 罗斯技术是一种强大的工具，它能让我们将原本的流体动力学问题转化为一个量子场论问题，从而利用非平衡量子场处理方面的进展。为了演示这项技术，我们将考虑相对论流体中自旋 - 2 模式的热涨落，在这样一个理论中，流体动力学是通过在弛豫时间近似下对玻尔兹曼方程取矩推导出来的。
