arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 0811.0181gr-qc
收藏

用LISA约束有效量子引力

Constraining effective quantum gravity with LISA

Nicolas Yunes, Lee Samuel Finn

摘要:

所有通向引力量子理论的现代途径--即,微扰量子引力单圈精确修正标准模型、弦论甚至圈量子引力中的整体手征流--需要用宇称违背的陈-西蒙斯项补充爱因斯坦-希尔伯特作用量。这样的项导致振幅双折射引力波传播:即,一个(圆)偏振态随着传播而放大,而另一个偏振态被衰减。拟议中的激光干涉仪空间天线(LISA)能够在宇宙学距离上观测引力波,这表明LISA观测可能会对这种量子引力的表现产生强烈的约束。在这里,我们报告的影响,时空振幅双折射上的信号LISA的计算是能够观察到从吸入大红移的超大质量黑洞二进制文件。我们发现,双折射表现在观测中作为一个异常的进动的二进制的轨道角动量,因为它朝着聚结,其大小取决于在辐射波前的世界线的陈-西蒙斯耦合的综合历史演变。我们估计,LISA可以把边界上的陈-西蒙斯修改的引力比目前的太阳系约束强几个数量级,从而提供了一个探测时空的量子结构。

英文摘要:

All modern routes leading to a quantum theory of gravity -- i.e., perturbative quantum gravitational one-loop exact correction to the global chiral current in the standard model, string theory, and perhaps even loop quantum gravity -- require supplementing the Einstein-Hilbert action with a parity-violating Chern-Simons term. Such a term leads to amplitude-birefringent gravitational wave propagation: i.e., one (circular) polarization state amplified with propagation while the other is attenuated. The proposed Laser Interferometer Space Antenna (LISA) is capable of observing gravitational wave sources at cosmological distances, suggesting the possibility that LISA observations may place a strong bound on this manifestation of quantum gravity. Here we report on a calculation of the effect that spacetime amplitude birefringence has on the signal LISA is capable of observing from inspiraling supermassive black hole binaries at large redshift. We find that the birefringence manifests itself in the observations as an anomalous precession of the binary's orbital angular momentum as it evolves toward coalescence, whose magnitude depends on the integrated history of the Chern-Simons coupling over the worldline of radiation wavefront. We estimate that LISA could place bounds on Chern-Simons modified gravity that are several orders of magnitude stronger than the present Solar System constraints, thus providing a probe of the quantum structure of spacetime.

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。

↑