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 wormholes in viable $f(R)$ gravity models are analysed. We areinterested in exact solutions for stress-energy tensor components depending ondifferent shape and redshift functions. Several solutions of gravitationalequations for different $f(R)$ models are examined. Found solutions imply noneed for exotic material, while this need is implied in the standard generaltheory of relativity. Simple expression for WEC violation near the throat isderived and analysed. High curvature regime is also discussed, as well as thequestion of the highest possible values of Ricci scalar for which WEC is notviolated near the throat, and corresponding functions are calculated for theseveral models. The approach here differs from the one that has been commonsince no additional assumptions to simplify the equations are made, andfunctions in $f(R)$ models are not taken to be arbitrary functions, but rathera feature of the theory that has to be evaluated on the basis of consistencywith observations for the Solar System and cosmological evolution.

Wormholes in viable $f(R)$ modified theories of gravity and Weak Energy Condition