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

In the de Sitter gauge theory (DGT), the fundamental variables are the deSitter (dS) connection and the gravitational Higgs/Goldstone field $\xi^A$.Previously, a model for DGT was analyzed, which generalizes theMacDowell--Mansouri gravity to have a variable cosmological constant$\Lambda=3/l^2$, where $l$ is related to $\xi^A$ by $\xi^A\xi_A=l^2$. It wasshown that the model sourced by a perfect fluid does not support a radiationepoch and the accelerated expansion of the parity invariant universe. In thiswork, I consider a similar model, namely, the Stelle--West gravity, and coupleit to a modified perfect fluid, such that the total Lagrangian 4-form ispolynomial in the gravitational variables. The Lagrangian of the modified fluidhas a nontrivial variational derivative with respect to $l$, and as a result,the problems encountered in the previous work no longer appear. Moreover, toexplore the elegance of the general theory, as well as to write down the basicframework, I perform the Lagrange--Noether analysis for DGT sourced by a matterfield, yielding the field equations and the identities with respect to thesymmetries of the system. The resulted formula are dS covariant and do not relyon the existence of the metric field.

Cosmology of a polynomial model for de Sitter gauge theory sourced by a fluid