English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Conventional estimators of the anisotropic power spectrum and two-pointcorrelation function (2PCF) adopt the `Yamamoto approximation', fixing theline-of-sight of a pair of galaxies to that of just one of its members. Whilstthis is accurate only to first-order in the characteristic opening angle$\theta_\max$, it allows for efficient implementation via Fast FourierTransforms (FFTs). This work presents practical algorithms for computing thepower spectrum and 2PCF multipoles using pairwise lines-of-sight, adoptingeither the galaxy midpoint or angle bisector definitions. Using newly derivedinfinite series expansions for spherical harmonics and Legendre polynomials, weconstruct estimators accurate to arbitrary order in $\theta_\max$, though notethat the midpoint and bisector formalisms themselves differ at fourth order.Each estimator can be straightforwardly implemented using FFTs, requiring onlymodest additional computational cost relative to the Yamamoto approximation. Wedemonstrate the algorithms by applying them to a set of realistic mock galaxycatalogs, and find both procedures produce comparable results for the 2PCF,with a slight preference for the bisector power spectrum algorithm, albeit atthe cost of greater memory usage. Such estimators provide a useful method toreduce wide-angle systematics for future surveys.

Beyond Yamamoto: Anisotropic Power Spectra and Correlation Functions with Pairwise Lines-of-Sight