Modelling pulsar timing noise

背景：观察到脉冲星--旋转的中子星--逐渐向下旋转，动能的明显损失平衡了来自恒星的电磁波和引力波能量的流量。这种向下旋转是平稳的，但并不是完全如此，偏离简单的计时模型被称为脉冲星计时噪声。这种噪音的来源尚不清楚。这个项目的目的是开发描述这一现象的数学模型。关键目标和目标：关键目标是建立一个中子星模型，该模型包含在这个问题中可能是重要的广泛的物理输入。这种模型的输出将与实际的定时噪声进行比较，并调整模型参数，以便尽可能准确地再现观察到的自旋行为。这样，流体和固体在重力、密度和磁场的极端情况下的行为将被探测，而这种方式在地球实验室是根本不可能的。新的方法：新的方法在于开发微扰技术来描述均匀刚体自旋的微小偏离，包括重力、弹性和磁力。然后将开发新的数值技术来在计算机上演化该系统，并用于探索该模型的结果。EPSRC研究领域：中子星的高度复杂的物理意味着该项目与EPSRC的多个研究领域相关。数学物理和复杂性科学是最明显的相关领域，但也有重叠与冷原子和分子，凝聚态物质：磁性和磁性材料，以及量子流体和固体。

Context: Pulsars - rotating neutron stars - are observed to gradually spin down, with the apparent loss in kinetic energy balancing a flux of electromagnetic and gravitational wave energy from the star. This spin down is smooth, but not perfectly so, with departures from a simple timing model being known as pulsar timing noise. The origin of this noise is not understood. The aim of this project is to develop mathematical models that describe this phenomenon.Key objective and aims: the key objective is to build a model of a neutron star that incorporates the wide range of physical inputs that are likely to be important in this problem. The outputs of such a model would be compared against real timing noise and the model parameters adjusted so as to reproduce as accurately as possible the observed spin behaviour. In this way, the behaviour of fluids and solids in extremes of gravity, density and magnetic field would be probed, in a way that would simply not be possible in a terrestrial laboratory.Novel methodology: the novel methodology lies in developing perturbation techniques to describe small departures from uniform rigid body spin-down, that include gravitational, elastic and magnetic forces. Then new numerical techniques to evolve the system on a computer would be developed, and used to explore the consequences of the model.EPSRC research areas: The highly complex physics of neutron stars means that this project is relevant to multiple EPSRC research areas. Mathematical physics and Complexity science are the most obviously relevant areas, but there is also overlap with Cold atoms and molecules, Condensed matter: magnetism and magnetic materials, and Quantum fluids and solids.