Technische Universität Darmstadt, Department of Physics, 64289 Darmstadt, Germany.
ExtreMe Matter Institute EMMI, GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany.
Phys Rev Lett. 2023 Feb 17;130(7):072701. doi: 10.1103/PhysRevLett.130.072701.
We calculate the equation of state of asymmetric nuclear matter at finite temperature based on chiral effective field theory interactions to next-to-next-to-next-to-leading order. Our results assess the theoretical uncertainties from the many-body calculation and the chiral expansion. Using a Gaussian process emulator for the free energy, we derive the thermodynamic properties of matter through consistent derivatives and use the Gaussian process to access arbitrary proton fraction and temperature. This enables a first nonparametric calculation of the equation of state in beta equilibrium, and of the speed of sound and the symmetry energy at finite temperature. Moreover, our results show that the thermal part of the pressure decreases with increasing densities.
我们基于手征有效场理论相互作用，计算了有限温度下非对称核物质的状态方程，精度达到次领头阶。我们的结果评估了多体计算和手征展开带来的理论不确定性。通过自由能的高斯过程模拟器，我们通过一致导数推导出物质的热力学性质，并使用高斯过程来获取任意的质子分数和温度。这使得我们能够首次对手征平衡中的物态方程、声速和有限温度下的对称能进行非参数计算。此外，我们的结果表明，压力的热部分随着密度的增加而减小。
