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

In setting up initial conditions for ensembles of cosmological N-bodysimulations there are, fundamentally, two choices: either maximizing thecorrespondence of the initial density field to the assumed fourier-spaceclustering or, instead, matching to real-space statistics and allowing the DCmode (i.e. overdensity) to vary from box to box as it would in the realuniverse. As a stringent test of both approaches, I perform ensembles ofsimulations using power law and a "powerlaw times a bump" model inspired bybaryon acoustic oscillations (BAO), exploiting the self-similarity of theseinitial conditions to quantify the accuracy of the matter-matter two-pointcorrelation results. The real-space method, which was originally proposed byPen 1997 and implemented by Sirko 2005, performed well in producing theexpected self-similar behavior and corroborated the non-linear evolution of theBAO feature observed in conventional simulations, even in thestrongly-clustered regime (sigma8 >= 1). In revisiting the real-space methodchampioned by Sirko 2005, it was also noticed that this earlier studyoverlooked an important integral constraint correction to the correlationfunction in results from the conventional approach that can be important inLambdaCDM simulations with Lbox =< 1 Gpc/h and on scales r >= Lbox / 10.Rectifying this shows that the fourier space and real space methods are aboutequally accurate and efficient for modeling the evolution and growth of thecorrelation function, contrary to previous claims. An appendix provides auseful independent-of-epoch analytic formula for estimating the importance ofthe integral constraint bias on correlation function measurements in LambdaCDMsimulations.

Keeping It Real: Revisiting a Real-Space Approach to Running Ensembles of Cosmological N-body Simulations