论文标题
同构理论超出热平衡
Isomorph theory beyond thermal equilibrium
论文作者
论文摘要
本文将同构理论推广到不在热平衡中的系统。假定该系统是r-simple，即具有势能，作为所有粒子坐标的函数，$ \ textbf {r} $遵守隐藏的尺度易变条件$ u（\ textbf {r} _ {\ rm a} _ {\ rm a}） u（λ\ textbf {r} _ {\ rm a}）<u（λ\ textbf {r} _ {\ rm b}）$。在密度和全身温度定义的相图中，将“全身性异构形成”作为恒定熵的线引入，这是平均势能等于$ u（\ textbf {r}）$的平均势能的温度。如果系统性和浴室温度之间存在恒定比率，则动力学是沿着全身性异构体不变的。在热平衡中，全身温度等于浴温的温度，并回收了原始的同构形式。在涉及非线性稳态剪切流，零温塑料流和玻璃态同构的模拟中，新方法在先前发表的同构不变性的一致框架内合理化了。该论文简要介绍了粒状培养基，身体衰老和活性物质。最后，我们讨论了定义减少量的能量单位应基于系统性而不是浴室温度的可能性。
This paper generalizes isomorph theory to systems that are not in thermal equilibrium. The systems are assumed to be R-simple, i.e., have a potential energy that as a function of all particle coordinates $\textbf{R}$ obeys the hidden-scale-invariance condition $U(\textbf{R}_{\rm a})<U(\textbf{R}_{\rm b})\Rightarrow U(λ\textbf{R}_{\rm a})<U(λ\textbf{R}_{\rm b})$. "Systemic isomorphs" are introduced as lines of constant excess entropy in the phase diagram defined by density and systemic temperature, which is the temperature of the equilibrium state point with average potential energy equal to $U(\textbf{R})$. The dynamics is invariant along a systemic isomorph if there is a constant ratio between the systemic and the bath temperature. In thermal equilibrium, the systemic temperature is equal to the bath temperature and the original isomorph formalism is recovered. The new approach rationalizes within a consistent framework previously published observations of isomorph invariance in simulations involving nonlinear steady-state shear flows, zero-temperature plastic flows, and glass-state isomorphs. The paper relates briefly to granular media, physical aging, and active matter. Finally, we discuss the possibility that the energy unit defining reduced quantities should be based on the systemic rather than the bath temperature.
