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

Through a very careful analysis Kolopanis and collaborators identified anegative power spectrum (PS) systematic. The 21 cm cosmology community hasassumed that any observational systematics would add power, as negative PS arenon-physical. In addition to the mystery of their origin, negative PSsystematics raise the spectre of artificially lowering upper limits on the 21cm PS. It appears that the source of the negative PS systematics is a subtleinteraction between choices in how the PS estimate is calculated andbaseline-dependent systematic power. In this paper we present a statisticalmodel of baseline dependent systematics to explore how negative PS systematicscan appear and their statistical characteristics. This leads us torecommendations on when and how to consider negative PS systematics whenreporting observational 21 cm cosmology upper limits.

The Statistics of Negative Power Spectrum Systematics in some 21 cm Analyses