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

We show that for every $2\le \xi<\omega_1$ there exists a Haar null set in$\mathbb{Z}^\omega$ that is the difference of two $\mathbf{\Pi}^0_\xi$ sets butnot contained in any $\mathbf{\Pi}^0_\xi$ Haar null set. In particular, thereexists a Haar null set in $\mathbb{Z}^\omega$ that is the difference of two$G_\delta$ sets but not contained in any $G_\delta$ Haar null set. Thispartially answers a question of M. Elekes and Z. Vidny\'anszky. To prove this,we also prove a theorem which characterizes the Haar null subsets of$\mathbb{Z}^\omega$.

Low complexity Haar null sets without G_{\delta} hulls in Z^\omega