标题： 随机时空对星系旋转曲线的异常贡献 显示英文标题

标题： Anomalous contribution to galactic rotation curves due to stochastic spacetime

摘要： 我们考虑一种量子引力的替代方案，在该方案中，时空度规被视为经典，即使物质场仍然是量子的。 该理论的一致性必然要求度规以随机方式演化。 在这里，我们表明这种随机行为会导致低加速度情况下的广义相对论修改。 在低加速度区域，由引力场产生的加速度方差相对于牛顿势产生的加速度要高得多，并可以作为熵力，导致偏离爱因斯坦的广义相对论理论。 我们表明，在这种“扩散区域”中，从引力角度来看，熵力似乎是对物质分布的贡献。 我们通过路径积分形式主义计算度规期望值的修改，并发现了一个异常贡献，这对应于一个宇宙学常数，与一个用于在没有暗物质的情况下拟合星系旋转曲线的贡献呈反相关。 我们提醒，在得出结论之前需要更深入地理解这一效应，这很可能是通过数值模拟实现的，并提供了一个计算偏离广义相对论的模板，该模板可作为时空布朗运动的实验特征。 显示英文摘要

摘要： We consider a proposed alternative to quantum gravity, in which the spacetime metric is treated as classical, even while matter fields remain quantum. Consistency of the theory necessarily requires that the metric evolve stochastically. Here, we show that this stochastic behaviour leads to a modification of general relativity at low accelerations. In the low acceleration regime, the variance in the acceleration produced by the gravitational field is high in comparison to that produced by the Newtonian potential, and can act as an entropic force, causing a deviation from Einstein's theory of general relativity. We show that in this "diffusion regime", the entropic force acts from a gravitational point of view, as if it were a contribution to the matter distribution. We compute modifications to the expectation value of the metric via the path integral formalism, and find an anomalous contribution which corresponds to a cosmological constant, anti-correlated with a contribution which has been used to fit galactic rotation curves without dark matter. We caution that a greater understanding of this effect is needed before conclusions can be drawn, most likely through numerical simulations, and provide a template for computing the deviation from general relativity which serves as an experimental signature of the Brownian motion of spacetime.