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

The Levi-Civita Bertotti Robinson (LBR) spacetime is investigated in various coordinate systems.By means of a general formalism for constructing coordinates in conformally flat spacetimes, coordinatetransformations between the different coordinate systems are deduced. We discuss the motion of thereference frames in which the different coordinate systems are comoving. Furthermore we characterize themotion of the different reference frames by their normalized timelike Killing vector fields, i.e. by the fourvelocity fields of the reference particles. We also deduce the formulae in the different coordinate systems forthe embedding of the LBR spacetime in a flat 6-dimensional manifold. In particular we discuss a scenariowith a spherical domain wall having LBR spacetime outside the wall and flat spacetime inside. We alsodiscuss the internal flat spacetime using the same coordinate systems as in the external LBR spacetimewith continuous metric at the wall. Among the different cases one represents a Milne-LBR universe modelwith a part of the Milne universe inside the wall and an infinitely extended LBR universe outside it. In anappendix we define combinations of trigonometric and hyperbolic functions that we call k-functions andpresent a new k-function calculus

Different representations of the Levi-Civita Bertotti Robinson solution