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 this study, we investigate a cosmological model involving a negativecosmological constant (AdS vacua in the dark energy sector). We consider aquintessence field on top of a negative cosmological constant and study itsimpact on cosmological evolution and structure formation. We use the powerspectrum of the redshifted HI 21 cm brightness temperature maps from thepost-reionization epoch as a cosmological probe. The signature of baryonacoustic oscillations (BAO) on the multipoles of the power spectrum is used toextract measurements of the angular diameter distance $D_A(z)$ and the Hubbleparameter $H(z)$. The projected errors on these are then subsequently employedto forecast the constraints on the model parameters ($\Omega_\Lambda, w_0,w_a$) using Markov Chain Monte Carlo techniques. We find that a negativecosmological constant with a phantom dark energy equation of state (EoS) and ahigher value of $H_0$ is viable from BAO distance measurements data derivedfrom galaxy samples. We also find that BAO imprints on the 21cm power spectrumobtained from a futuristic SKA-mid like experiment yield a $1-\sigma$ error ona negative cosmological constant and the quintessence dark energy EoSparameters to be $\Omega_\Lambda=-1.030^{0.589}_{-1.712}$ and$w_0=-1.023^{0.043}_{-0.060}$, $w_a=-0.141^{0.478}_{-0.409}$ respectively.

Post-reionization HI 21-cm signal: A probe of negative cosmological constant