论文标题

动力学推断和超对称性

Dynamical field inference and supersymmetry

论文作者

Westerkamp, Margret, Ovchinnikov, Igor, Frank, Philipp, Enßlin, Torsten

论文摘要

关于不断发展的物理领域的知识在科学,技术和经济学中至关重要。动态场推理(DFI)解决了从有限数据中重建随机驱动的,动态发展的领域的问题。它依赖于信息字段理论(IFT),这是字段的信息理论。在这里,在教学讨论中建立了DFI,IFT和最近开发的超对称性理论(STS)的关系。在IFT中,可以从完整的时空推理问题的分区函数中计算现场期望值。推理问题的分区函数调用功能性狄拉克功能,以确保动力学以及与场相关的功能决定因素,以建立适当的归一化,都阻碍了所有字段配置对路径积分的必要评估。 STS分别通过引入Fermionic Ghost和Bosonic Lagrange领域来代替这些有问题的表达。这些磁场的作用具有超对称性,这意味着在玻色子和费米子之间存在交换操作,从而使系统不变。与此相反,动态场的测量不符合这种超对称性。超对称性也可以自发折断,在这种情况下,系统会混沌演变。这会影响系统的可预测性,从而使DFI更具挑战性。我们在Feynman图的帮助下研究了测量约束与简化的说明性系统的非线性混沌动力学的相互作用,并表明费米子校正对于获得系统轨迹的正确后统计是必不可少的。

Knowledge on evolving physical fields is of paramount importance in science, technology, and economics. Dynamical field inference (DFI) addresses the problem of reconstructing a stochastically driven, dynamically evolving field from finite data. It relies on information field theory (IFT), the information theory for fields. Here, the relations of DFI, IFT, and the recently developed supersymmetric theory of stochastics (STS) are established in a pedagogical discussion. In IFT, field expectation values can be calculated from the partition function of the full space-time inference problem. The partition function of the inference problem invokes a functional Dirac function to guarantee the dynamics, as well as a field-dependent functional determinant, to establish proper normalization, both impeding the necessary evaluation of the path integral over all field configurations. STS replaces these problematic expressions via the introduction of fermionic ghost and bosonic Lagrange fields, respectively. The action of these fields has a supersymmetry, which means there exists an exchange operation between bosons and fermions that leaves the system invariant. In contrast to this, measurements of the dynamical fields do not adhere to this supersymmetry. The supersymmetry can also be broken spontaneously, in which case the system evolves chaotically. This affects the predictability of the system and thereby make DFI more challenging. We investigate the interplay of measurement constraints with the non-linear chaotic dynamics of a simplified, illustrative system with the help of Feynman diagrams and show that the Fermionic corrections are essential to obtain the correct posterior statistics over system trajectories.

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