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 Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

We present a new method to compute the deflection of light rays in aperturbed FLRW geometry. We exploit the properties of the Geodesic Light Cone(GLC) gauge where null rays propagate at constant angular coordinatesirrespectively of the given (inhomogeneous and/or anisotropic) geometry. Thegravitational deflection of null geodesics can then be obtained, in any othergauge, simply by expressing the angular coordinates of the given gauge in termsof the GLC angular coordinates. We apply this method to the standard Poissongauge, including scalar perturbations, and give the full result for thedeflection effect in terms of the direction of observation and observedredshift up to second order, and up to third order for the leading lensingterms. We also compare our results with those presently available in theliterature and, in particular, we provide a new non trivial check of a previousresult on the luminosity-redshft relation up to second order in cosmologicalperturbation theory.

A new approach to the propagation of light-like signals in perturbed cosmological backgrounds