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 an application to cosmological models in $f({\cal R})$ theorieswithin the Palatini formalism of a method that combines cosmography and theexplicit form of the field equations in the calculation of the redshift drift.The method yields a sequence of constraint equations which lead to limits onthe parameter space of a given $f({\cal R})$-model. Two particular families of$f({\cal R})$-cosmologies capable of describing the current dynamics of theuniverse are explored here: (i) power law theories of the type $f({\calR})={\cal R}-\beta /{\cal R}^n$, and (ii) theories of the form $f({\calR})={\cal R}+\alpha \ln{{\cal R}} -\beta$. The constraints on $(n,\beta)$ and$(\alpha,\beta)$, respectively, limit the values to intervals that are narrowerthan the ones previously obtained. As a byproduct, we show that when applied toGeneral Relativity, the method yields values of the kinematic parameters withmuch smaller errors that those obtained directly from observations.

Cosmography and the redshift drift in Palatini $f({\cal R})$ theories