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

In this work we derive the junction conditions for the matching between twospacetimes at a separation hypersurface in the perfect-fluid version of$f\left(R,T\right)$ gravity, not only in the usual geometrical representationbut also in a dynamically equivalent scalar-tensor representation. We startwith the general case in which a thin-shell separates the two spacetimes at theseparation hypersurface, for which the general junction conditions are deduced,and the particular case for smooth matching is considered when thestress-energy tensor of the thin-shell vanishes. The set of junction conditionsis similar to the one previously obtained for $f\left(R\right)$ gravity butfeatures also constraints in the continuity of the trace of the stress-energytensor $T_{ab}$ and its partial derivatives, which force the thin-shell tosatisfy the equation of state of radiation $\sigma=2p_t$. As a consequence, anecessary and sufficient condition for spherically symmetric thin-shells tosatisfy all the energy conditions is the positivity of its energy density$\sigma$. For specific forms of the function $f\left(R,T\right)$, thecontinuity of $R$ and $T$ ceases to be mandatory but a gravitationaldouble-layer arises at the separation hypersurface. The Martinez thin-shellsystem and a thin-shell surrounding a central black-hole are provided asexamples of application.

Junction conditions and thin-shells in perfect-fluid $f\left(R,T\right)$ gravity