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arXiv · 1904.11055

Efficient parallel algorithm for estimating higher-order polyspectra

Joseph Tomlinson·Donghui Jeong·Juhan Kim
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Abstract

Nonlinearities in the gravitational evolution, galaxy bias, and redshift-space distortion drive the observed galaxy density fields away from the initial near-Gaussian states. Exploiting such a non-Gaussian galaxy density field requires measuring higher-order correlation functions, or, its Fourier counterpart, polyspectra. Here, we present an efficient parallel algorithm for estimating higher-order polyspectra. Based upon the Scoccimarro estimator, the estimator avoids direct sampling of polygons by using the Fast-Fourier Transform (FFT), and the parallelization overcomes the large memory requirement of the original estimator. In particular, we design the memory layout to minimize the inter-CPU communications, which excels in the code performance.

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Joseph Tomlinson, Donghui Jeong, Juhan Kim. 2019-04-24. Efficient parallel algorithm for estimating higher-order polyspectra. https://doi.org/10.3847/1538-3881%2Fab3223

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