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

There is ongoing interest in adopting various tools and ideas from generalrelativity for optical applications and the study of light propagation throughnatural or engineered media. Here, the covariant kinematics of lightpropagating through arbitrary dielectric media in curved space-times arederived, allowing for analysis and tracing of congruences of light throughmedia that may smoothly vary in character between vacuum, positivelyrefracting, and negatively refracting; or null, timelike, and spacelike withrespect to the background metric. The kinematics are then used to generalizethe Raychaudhuri equation -- an important tool in general relativity thatdescribes the focus of a congruence. These results will be useful for theanalysis of optical devices, particularly those designed using transformationoptics, and serve as theoretical tools to study generalized concepts in generalrelativity.

Covariant kinematics of light in media and a generalized Raychaudhuri equation