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 Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

The source of the tension between local SN Ia based Hubble constantmeasurements and those from the CMB or BAO+BBN measurements is one of the mostinteresting unknowns of modern cosmology. Sample variance forms a key componentof the error on the local measurements, and will dominate the error budget inthe future as more supernovae are observed. Many methods have been proposed toestimate sample variance in many contexts, and we compared results from anumber of them in Zhai \& Percival (2022), confirming that sample variance forthe Pantheon supernovae sample does not solve the Hubble tension. We now extendthis analysis to include a method based on analytically calculatingcorrelations between the radial peculiar velocities of supernovae, comparingthis technique with results from numerical simulations, which can be considereda non-linear Monte-Carlo solution that works similarly. We consider thedependence of these errors on the linear power spectrum and how non-linearvelocities contribute to the error. Using this technique, and matching samplevariance errors, we can define an effective volume for supernovae samples,finding that the Pantheon sample is equivalent to a top-hat sphere of radius$\sim220~h^{-1}$Mpc. We use this link between sample-variance errors to compute$\Delta H_{0}$ for idealised surveys with particular angular distributions ofsupernovae. For example, a half-sky survey at the Pantheon depth has thepotential to suppress the sample variance of $H_{0}$ to $\sim0.1$ kms$^{-1}$Mpc$^{-1}$, a significant improvement compared with the current result.Finally, we consider the strength of large-scale velocity power spectrumrequired to explain the Hubble tension using sample variance, finding itrequires an extreme model well beyond that allowed by other observations.

The effective volume of supernovae samples and sample variance