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

One of the sources of incompatibility between general relativity and quantummechanics is perturbative non-renormalizability of quantum gravity in $3+1$spacetime dimensions. Here, we show that in the presence of disorder induced byrandom networks of observers measuring covariant quantities (such as scalarcurvature) $(3+1)$-dimensional quantum gravity exhibits an effectivedimensional reduction at large spatio-temporal scales, which is analogous tothe Parisi-Sourlas phenomenon observed for quantum field theories in randomexternal fields. After averaging over associated disorder and focusing on theinfrared dynamics of the theory we find that the upper critical dimension ofquantum gravity is lifted from $D_{{\rm cr}}=1+1$ to $D_{{\rm cr}}=3+1$dimensions.

Parisi-Sourlas-like dimensional reduction of quantum gravity in the presence of observers