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

Lorentz invariance is the fundamental symmetry of Einstein's theory ofspecial relativity, and has been tested to great level of detail. However,theories of quantum gravity at the Planck scale indicate that Lorentz symmetrymay be broken at that scale motivating further tests. While the Planck energyis currently unreachable by experiment, tiny residual effects at attainableenergies can become measurable when photons propagate over sufficiently largedistances. The Standard-Model Extension (SME) is an effective field theoryapproach to describe low-energy effects of quantum gravity theories. Lorentzand CPT symmetry violating effects are introduced by adding additional terms tothe Standard Model Lagrangian. These terms can be ordered by the mass dimensionof the corresponding operator, and the leading terms of interest have dimensiond = 5. Effects of these operators are a linear variation of the speed of lightwith photon energy, and a rotation of the linear polarization of photonsquadratic in photon energy, as well as anisotropy. We analyzed opticalpolarization data from 72 AGN and GRBs and derived the first set of limits onall 16 coefficients of mass dimension d = 5 of the SME photon sector. Ourconstraints imply a lower limit on the energy scale of quantum gravity of$10^6$ times the Planck energy, severly limiting the phase space for any theorythat predicts a rotation of the photon polarization quadratic in energy.

Planck-scale constraints on anisotropic Lorentz and CPT invariance violations from optical polarization measurements