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

The energy density, the pressure and the anisotropic stress of the relicgravitons do not have a unique gauge-invariant and frame-invariant expressionsince the equivalence principle ultimately forbids the localization of theenergy-momentum of the gravitational field. All the strategies proposed so farsuggest compatible descriptions inside the effective horizon but they lead tosharply different answers when the wavelengths of the gravitons exceed theHubble radius by remaining shorter than the typical extension of causallyconnected patches. We present a coherent discussion of the energy-momentumpseudo-tensors of the relic gravitons in the different kinematical regimes withthe aim of scrutinizing the mutual consistency of the competing suggestions.The various proposals are systematically compared by deducing and analyzing theexplicit form of the observables in realistic physical situations. Generallessons are drawn on the most plausible parametrization of the energy-momentumpseudo-tensor of the relic gravitons.

Effective energy density of relic gravitons