论文标题
粒状物质中干扰的有效的一般相对论描述
Effective General Relativistic Description of Jamming in Granular Matter
论文作者
论文摘要
我们在这里提出,粒状物质在红外极限中的某些观察特征,表现出{\ it Jamming}的现象,是由潜在的有效的一般相对论描述引起的。该提议源于粒状物质中颗粒物中颗粒物中颗粒物中粒子中粒子中粒子中的假设(\ it有效}弯曲的riemannian空间。在干扰开始时,其轨迹的终止是通过在这样一个空间中的聚集一致性的重点来获得的,这是Raychaudhuri方程的解决方案。尽管在两种情况下,曲率是否是通过外部应力(通过有效的爱因斯坦方程)来源的,但曲率是否是通过外部应力(通过有效的爱因斯坦方程)来提供的,这可能发生这种情况。对这种几何方法的明确预测是那些在达到困扰状态时相互扭曲的轨迹所起的负面作用。粒状相互作用,翻译和旋转不变性的局部对称性(对应于基于标准力的堵塞方法中的“力平衡”和“扭矩平衡”)是有效的一般相对性框架中固有的。基于标准静电学(矢量电荷理论)的张力变体,最近提供的有效状态的有效弹性模型被认为完全包含在有效的一般相对论描述的线性化版本中。
We propose here that certain observational features of granular matter in the infrared limit, exhibiting the phenomenon of {\it jamming}, arise from an underlying effective general relativistic description. The proposal stems from the assumption (which we justify on physical grounds) that grains in granular matter move freely in an {\it effective} curved Riemannian space. The termination of their trajectories at the onset of jamming is obtained from the focussing of a converging congruence of geodesics in such a space, as a solution of the Raychaudhuri equation for such congruences. This may happen irrespective of whether or not the curvature is sourced by external stresses (via an effective Einstein equation), although the properties of the resultant jammed state solution do differ in the two cases. A definite prediction of this geometrical approach is the negative role played by those trajectories which twist about each other, in reaching the jammed state. The local symmetries of granular interaction, translational and rotational invariance (corresponding to `force balance' and `torque balance' in standard force-based approaches to jamming) are inherent in the effective general relativity framework. A recently-proposed effective elasticity model of the jammed state, based on a tensorial variant of standard electrostatics (Vector Charge Theory), is seen to be entirely subsumed within the linearized version of the effective general relativistic description.