基于LSST超级新星的奇点速度测量生长率预测

In this work, we investigate the feasibility of measuring the cosmic growth-rate parameter, $f\sigma_8$, using peculiar velocities (PVs) derived from Type Ia supernovae (SNe Ia) in the Vera C. Rubin Observatory's Legacy Survey of Space and Time (LSST)。我们生产使用真实LSST观测策略的不同SN类型的模拟，包含噪声、来自Difference Image Analysis (DIA)管道的光度检测，以及从Uchuu UniverseMachine模拟中建模的PV场。我们测试了三个观察情景， ranging from ideal conditions with spectroscopic host-galaxy redshifts and spectroscopic SN classification, to more realistic settings involving photometric classification and contamination from non-Ia supernovae。Using a maximum-likelihood technique, we show that LSST can measure $f\sigma_8$ with a precision of $10\%$ in the redshift range $0.02 < z < 0.14$ in the most realistic case. Using three tomographic bins, LSST can constrain the growth-rate parameter with errors below $18\%$ up to $z = 0.14$。我们还测试了污染对最大似然方法的影响并发现，对于污染比例小于$\sim 2\%$，测量保持无偏。这些结果凸显了LSST SN Ia样本在补充高红移处的红移空间扭曲测量潜力，为测试广义相对论和暗能量模型提供了新的途径。