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 Tools annual

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 monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

In the presence of Lorentz violation, the Cerenkov-like process$\gamma\rightarrow\gamma+\pi^{0}$ may become allowed for sufficiently energeticphotons. Photons above the threshold would lose energy rapidly through pionemission. The fact that propagating photons with energies of up to 80 TeVsurvive to be observed on Earth allows us to place a one-sided constraint on anisotropic Lorentz violating parameter at the $7\times 10^{-13}$ level; this ismore than an order of magnitude better than best previous result.

Cerenkov-Like Emission of Pions by Photons in a Lorentz-Violating Theory