论文标题
热和磁化的玻感和费米子系统的剪切和散装粘性系数的一环量估计
One-loop Kubo estimations of the shear and bulk viscous coefficients for hot and magnetized Bosonic and Fermionic systems
论文作者
论文摘要
The expressions of the shear viscosity and the bulk viscosity components in the presence of an arbitrary external magnetic field for a system of hot charged scalar Bosons (spin-0) as well as for a system of hot charged Dirac Fermions (spin-$\frac{1}{2}$) have been derived by employing the one-loop Kubo Formalism.这是通过使用有限温度场理论的实时形式和适当的时间形式主义的实时形式主义来明确评估能量动量张量的热磁光谱函数来完成的。在目前的工作中，发现了非零磁场中粘性系数的表达中丰富的量子场理论结构，这与通过基于动力学理论的计算获得的各自表达式不同。但是，在没有磁场的情况下，已知对粘度的单环峰值和基于动力学理论的表达是相同的。我们已经确定粘度分量的基于Kubo和动力学理论的结果遵循类似的温度和磁场依赖性。动力学理论形式主义中的松弛时间和同步频率分别与繁殖物的热宽度和库博形式中带电粒子的兰道水平之间的过渡分别相连。我们认为，后一个数量的联系是非常新的，目前的工作可能是第一次解决这种解释以及粘度组件的新表达，而在现有作品中未见。
The expressions of the shear viscosity and the bulk viscosity components in the presence of an arbitrary external magnetic field for a system of hot charged scalar Bosons (spin-0) as well as for a system of hot charged Dirac Fermions (spin-$\frac{1}{2}$) have been derived by employing the one-loop Kubo Formalism. This is done by explicitly evaluating the thermo-magnetic spectral functions of the energy momentum tensors using the real time formalism of finite temperature field theory and the Schwinger proper time formalism. In the present work, a rich quantum field theoretical structure in the expressions of the viscous coefficients in non-zero magnetic field are found, which are different from their respective expressions obtained earlier via kinetic theory based calculations; though, in absence of magnetic field, the one-loop Kubo and the kinetic theory based expressions for the viscosities are known to be identical. We have identified that Kubo and kinetic theory based results of viscosity components follow similar kind of temperature and magnetic field dependency. The relaxation time and the synchrotron frequency in the kinetic theory formalism are realized to be connected respectively with the thermal width of propagator and the transitions among the Landau levels of the charged particles in the Kubo formalism. We believe that, the connection of latter quantities are quite new and probably the present work is the first time addressing this interpretation along with the new expressions of viscosity components, not seen in existing works.
