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 propose physically motivated spacetime uncertainty relations (STUR) forflat Friedmann-Lema\^{i}tre cosmologies. We show that the physical features ofthese STUR crucially depend on whether a particle horizon is present or not. Inparticular, when this is the case we deduce the existence of a maximal valuefor the Hubble rate (or equivalently for the matter density), thus providing anindication that quantum effects may rule out a pointlike big bang singularity.Finally, we costruct a concrete realisation of the corresponding quantumFriedmann spacetime in terms of operators on a Hilbert space.

Building non commutative spacetimes at the Planck length for Friedmann flat cosmologies