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

Metric theories of gravity are studied, beginning with a general action thatis quadratic in curvature and allows infinite inverse powers of thed'Alembertian operator, resulting in infrared non-local extensions of generalrelativity. The field equations are derived in full generality and theirconsistency is checked by verifying the Bianchi identities. The weak-fieldlimit is computed and a straightforward algorithm is presented to infer thepost-Newtonian corrections directly from the action. We then apply this tovarious infrared gravity models including non-local $Rf(R/ \Box)$ cosmology andnon-local dark energy and massive gravity models. Generically the Newtonianpotentials are not identical and deviate from the $1/r$ behaviour at largedistances. However, the former does not occur in a specific class of theoriesthat does not introduce additional degrees of freedom in flat spacetime. A newnonlocal model within this class is proposed, defined by the exponential of theinverse d'Alembertian. This model exhibits novel features, such as weakening ofthe gravity in the infrared, suggesting de-gravitation of the cosmologicalconstant.

Generalised Quadratic Curvature, Non-Local Infrared Modifications of Gravity and Newtonian Potentials