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arXiv 2005.04325astro-ph.CO
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用引力波和星系的奇特速度探测引力和结构生长

Probing gravity and growth of structure with gravitational waves and galaxies' peculiar velocity

Antonella Palmese, Alex G. Kim

摘要:

低红移速度场是宇宙结构和引力增长的独特探测器。我们建议使用距离引力波(GW)的检测,结合其宿主星系的红移从宽场光谱调查(如DESI,4MOST,TAIPAN),测量本地宇宙内的特殊运动。这种测量有可能限制增长率$fσ_8$和测试重力通过确定重力增长指数$γ$,补充其他特殊的速度测量的限制。我们发现,在$z\lesssim 0.2$,将被检测到的爱因斯坦望远镜(ET)的相关对应物的双中子星合并将能够约束$fσ_8$ $\sim 3\%$精度后,$10$年的操作时,结合从DESI和TAIPAN星系过密度。如果有更大的第三代GW探测器网络可用(例如,包括宇宙探测器),则可以在更短的时间尺度上达到相同的约束(对于3个探测器网络,为$\sim 5$年)。同样的事件(加上来自其宿主红移的信息)可以将$γ$限制为$σ_γ\lesssim 0.04$。这个约束条件足够精确,足以将广义相对论与$3σ$上其他流行的引力模型区分开来。当与星系超密度相结合时,这个约束被改进为$σ_γ\sim 0.02-0.03$。将星系的奇特速度与引力波探测结合起来用于宇宙学的潜力突出表明,在未来十年中,需要对附近的引力波事件进行广泛的光学到近红外跟踪,或者精确的GW定位。

英文摘要:

The low-redshift velocity field is a unique probe of the growth of cosmic structure and gravity. We propose to use distances from gravitational wave (GW) detections, in conjunction with the redshifts of their host galaxies from wide field spectroscopic surveys (e.g. DESI, 4MOST, TAIPAN), to measure peculiar motions within the local Universe. Such measurement has the potential to constrain the growth rate $fσ_8$ and test gravity through determination of the gravitational growth index $γ$, complementing constraints from other peculiar velocity measurements. We find that binary neutron star mergers with associated counterpart at $z\lesssim 0.2$ that will be detected by the Einstein Telescope (ET) will be able to constrain $fσ_8$ to $\sim 3\%$ precision after $10$ years of operations when combined with galaxy overdensities from DESI and TAIPAN. If a larger network of third generation GW detectors is available (e.g. including the Cosmic Explorer), the same constraints can be reached over a shorter timescale ($\sim 5$ years for a 3 detectors network). The same events (plus information from their hosts' redshifts) can constrain $γ$ to $σ_γ\lesssim 0.04$. This constraint is precise enough to discern General Relativity from other popular gravity models at $3σ$. This constraint is improved to $σ_γ\sim 0.02-0.03$ when combined with galaxy overdensities. The potential of combining galaxies' peculiar velocities with gravitational wave detections for cosmology highlights the need for extensive optical to near--infrared follow--up of nearby gravitational wave events, or exquisite GW localization, in the next decade.

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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