论文标题
用重力波和星系的特殊速度探测重力和结构的生长
Probing gravity and growth of structure with gravitational waves and galaxies' peculiar velocity
论文作者
论文摘要
低红移速度场是宇宙结构和重力生长的独特探测。我们建议使用重力波（GW）检测的距离，并结合其从广场光谱调查中的宿主星系的红移（例如Desi，最4个，Taipan），以测量当地宇宙中特殊运动。这种测量可能会通过确定重力生长指数$γ$来限制增长率$fσ_8$和测试重力，从而补充其他特殊速度测量的约束。 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.如果有一个较大的第三代GW检测器网络（例如，包括宇宙资源管理器），则可以在较短的时间表上达到相同的约束（对于3个检测器网络）。相同的事件（加上主机的红移信息）可以将$γ$限制为$σ_γ\ lyseSim 0.04 $。这种约束足以将一般相对论从其他流行的重力模型辨别为3σ$。与星系过重时，此约束将提高到$σ_γ\ sim 0.02-0.03 $。将星系的特殊速度与引力波检测相结合的潜力突出了接近附近的重力波事件或精致的GW定位，需要广泛的光学光学。
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.
