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arXiv 1104.5635gr-qc
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引力自作用力中的规范与平均

Gauge and Averaging in Gravitational Self-force

Samuel E. Gralla

摘要:

以前处理引力自作用力的困难在于,只有在特定规范(洛伦兹规范)中才有明确的力的公式,而一旦洛伦兹规范力已知,其他规范中的力必须通过变换定律来找到。对于一类满足"宇称条件“的规范,确保粒子的哈密顿质心是明确的,我表明,引力自作用力总是由裸引力的角平均。为了得到这个结果,我用一种新的方法取代了以前工作的计算策略,其中力的形式首先通过简单的操作固定到一个规范不变的部分,然后通过在专门设计的规范中工作来确定该部分,以简化计算。由于完全避免了阿达玛展开,并且度规微扰采用了非常简单的形式,因此这比洛伦兹规范提供了显著的计算节省。我还表明,由于一阶自作用力的影响,粒子的静止质量不会演变。最后,我考虑了“模和正则化”方案,用于计算黑洞背景时空中的自作用力,并使用力的角平均形式来表明,在所有宇称正则规范中可以执行相同的逐模减法。似乎合理的是,适当修改版本的雷奇-惠勒和辐射计(方便史瓦西和克尔,分别)是在这一类。

英文摘要:

A difficulty with previous treatments of the gravitational self-force is that an explicit formula for the force is available only in a particular gauge (Lorenz gauge), where the force in other gauges must be found through a transformation law once the Lorenz gauge force is known. For a class of gauges satisfying a ``parity condition'' ensuring that the Hamiltonian center of mass of the particle is well-defined, I show that the gravitational self-force is always given by the angle-average of the bare gravitational force. To derive this result I replace the computational strategy of previous work with a new approach, wherein the form of the force is first fixed up to a gauge-invariant piece by simple manipulations, and then that piece is determined by working in a gauge designed specifically to simplify the computation. This offers significant computational savings over the Lorenz gauge, since the Hadamard expansion is avoided entirely and the metric perturbation takes a very simple form. I also show that the rest mass of the particle does not evolve due to first-order self-force effects. Finally, I consider the ``mode sum regularization'' scheme for computing the self-force in black hole background spacetimes, and use the angle-average form of the force to show that the same mode-by-mode subtraction may be performed in all parity-regular gauges. It appears plausible that suitably modified versions of the Regge-Wheeler and radiation gauges (convenient to Schwarzschild and Kerr, respectively) are in this class.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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