论文标题
与星系数计数的统一近似 - 红移空间相关函数
The flat-sky approximation to galaxy number counts -- redshift space correlation function
论文作者
论文摘要
我们研究了包括相对论效应在内的星系数计数的统一近似值，并评估其相对于全高结果的性能和准确性。 We find an agreement of up to 5% for the local and lensing contributions to the 2-point correlation function and its multipoles at $z > 0.5$, and up to 1% for the multipoles alone at $z > 1$ and separations $\lesssim 250$ Mpc/$h$, with a speed-up of over a factor of 1000. Using a semi-analytic method, which has been implemented in a new version of the code COFFE, along with the Limber综合贡献的近似值，我们进一步提高了性能，从而使平面多物的计算要比全面计算快10000倍以上，该计算可用于极大地加速Markov Chain Monte Carlo采样以进行宇宙参数估计。
We study the flat-sky approximation for galaxy number counts including relativistic effects, and assess its performance and accuracy with respect to the full-sky result. We find an agreement of up to 5% for the local and lensing contributions to the 2-point correlation function and its multipoles at $z > 0.5$, and up to 1% for the multipoles alone at $z > 1$ and separations $\lesssim 250$ Mpc/$h$, with a speed-up of over a factor of 1000. Using a semi-analytic method, which has been implemented in a new version of the code COFFE, along with the Limber approximation for the integrated contributions, we further increase the performance, allowing the computation of the flat-sky multipoles to be done over 10000 times faster than in the full-sky calculation, which could be used to greatly speed-up Markov chain Monte Carlo sampling for cosmological parameter estimation.
