论文标题
LCDM中的星系和光晕角簇和修饰的重力宇宙学
Galaxy and halo angular clustering in LCDM and Modified Gravity cosmologies
论文作者
论文摘要
使用$ n $ body模拟的套件，我们研究了$ \ mathrm {λ\ text {cdm}} $中星系，光环和暗物质的角聚类，并修改了重力（mg）方案。我们考虑了这样的MG模型的两个一般类别，一种是$ f（r）$重力，另一个是Dvali-Gabadadze-Porrati Brane World（NDGP）的普通分支。为了测量角聚类，我们构建了一组观察者框架的灯杆和由此产生的模拟天空目录。我们专注于区域平均的角相关功能，$ W_J $和相关的减少累积物，$ S_J \ Equiv W_J/W_2^{（J-1）} $，并使用Counts-In-Cells（CIC）稳健地测量它们至9阶。我们发现$ 0.15 <z <0.3 $是最佳的红移范围，以最大程度地提高我们的LightCones中的MG信号。分析两种类型统计的各种量表，我们确定了从一般相对论（GR）的MG测量中最多20 \％的相对偏移，信号意义各不相同。对于Halos和Galaxies的情况，我们发现$ 3 $ RD订单统计信息提供了不同结构地层场景的最敏感的探测器，均为$ W_3 $和减少的偏度，$ S_3 $，从2σ$ $4σ$从Angular Scares $θ\ sim 0.13 ^ ^ ^\ comp $ comp $ $ s_ $ s_ $。光滑暗物质场的MG聚类的特征是GR的更强偏差（$ \ stackrel {>} {{} _ \ sim}5σ$）来自GR，尽管以$θ\ sim0.08^\ Circ $的较小尺度，Baryonic Physics已经很重要。最后，我们强调的是，与现有和即将进行的最新光度测量相比，我们的模拟光环和星系目录的表面密度相当低。这为在未来的应用中使用角群集测试GR和MG打开了令人兴奋的潜力，其精度和显着性比此处报道的更高。
Using a suite of $N$-body simulations we study the angular clustering of galaxies, halos, and dark matter in $\mathrm{Λ\text{CDM}}$ and Modified Gravity (MG) scenarios. We consider two general categories of such MG models, one is the $f(R)$ gravity, and the other is the normal branch of the Dvali-Gabadadze-Porrati brane world (nDGP). To measure angular clustering we construct a set of observer-frame lightcones and resulting mock sky catalogs. We focus on the area-averaged angular correlation functions, $W_J$, and the associated reduced cumulants, $S_J\equiv W_J/W_2^{(J-1)}$, and robustly measure them up to the 9th order using counts-in-cells (CIC). We find that $0.15 < z < 0.3$ is the optimal redshift range to maximize the MG signal in our lightcones. Analyzing various scales for the two types of statistics, we identify up to 20\% relative departures in MG measurements from general relativity (GR), with varying signal significance. For the case of halos and galaxies, we find that $3$rd order statistics offer the most sensitive probe of the different structure formation scenarios, with both $W_3$ and the reduced skewness, $S_3$, reaching from $2σ$ to $4σ$ significance at angular scales $θ\sim 0.13 ^\circ$. The MG clustering of the smooth dark matter field is characterized by even stronger deviations ($\stackrel{>}{{}_\sim} 5σ$) from GR, albeit at a bit smaller scales of $θ\sim0.08^\circ$, where baryonic physics is already important. Finally, we stress out that our mock halo and galaxy catalogs are characterized by rather low surface number densities when compared to existing and forthcoming state-of-the-art photometric surveys. This opens up exciting potential for testing GR and MG using angular clustering in future applications, with even higher precision and significance than reported here.
