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

Causality constrains the gravitational interactions of massive higher spinparticles in both AdS and flat spacetime. We explore the extent to which theseconstraints apply to composite particles, explaining why they do not rule outmacroscopic objects or hydrogen atoms. However, we find that they do apply toglueballs and mesons in confining large $N$ gauge theories. Assuming suchtheories contain massive bound states of general spin, we find parametricbounds in $(3+1)$ spacetime dimensions of the form $N\lesssim\frac{M_{Pl}}{\Lambda_{\text{QCD}}}$ relating $N$, the QCD scale, and thePlanck scale. We also argue that a stronger bound replacing$\Lambda_{\text{QCD}}$ with the UV cut-off scale may be derived from eikonalscattering in flat spacetime.

A Species or Weak-Gravity Bound for Large $N$ Gauge Theories Coupled to Gravity