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

We study how primordial non‐Gaussianity affects the pairwise velocity probability density function (PDF) using an analytical model and cosmological   N  ‐body simulations. We adopt the local type non‐Gaussian models characterized by   f  nl  , and examine both the linear velocity difference PDF and the linear pairwise velocity PDF. We show explicitly how   f  nl   induces correlations between originally independent velocities along the parallel and the perpendicular to the line of separation directions. We compare the model results with measurements from   N  ‐body simulations of the non‐Gaussian models. Linear theory fails to predict the PDF in the   f  nl   models. Therefore, we develop an analytic model based on the Zeldovich approximation to describe the evolution of the velocity PDF. Our analytical model and simulation results show remarkably good agreement in both the parallel and the perpendicular directions for the PDF profiles, as well as the change in the PDF due to primordial non‐Gaussianity. The agreement is particularly good for relatively small separations ( &lt;10  h  −1  Mpc ). The inclusion of the evolution of the velocity PDF is important to obtain a good description on the signature of primordial non‐Gaussianity in the PDF. Our model provides the foundation to constrain   f  nl   using the peculiar velocity in future surveys.

The pairwise velocity probability density function in models with local primordial non‐Gaussianity