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/

Zendy Plus

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

Zendy Tools

Zendy Open

We investigate the primordial power spectrum of cosmological tensorperturbations in the dressed metric approach to Loop Quantum Cosmology. Wecompute the background-dependent effective mass that affects their propagationusing the effective description of Loop Quantum Cosmology and show that thismass can be approximated in different cosmological epochs by appropriateanalytic functions. Moreover, in each of those epochs we can analytically solvethe propagation of the perturbations, then obtaining the general solutionglobally by continuity requirements. On the other hand, since there are regimesfar away from slow roll in the considered background evolution, theBunch-Davies state does not provide a privileged choice of vacuum that wouldpick out a specific solution for the perturbations. Instead, we select thestate of these perturbations by a recently proposed criterion that removesunwanted oscillations in the power spectrum. We compute the spectrum of thisvacuum and compare it with other spectra obtained in the literature, especiallywith one corresponding to the hybrid approach to Loop Quantum Cosmology.Finally, we notice that the same type of background dynamics is found in aphenomenological approach to quantum gravity based on thermodynamics, allowingin this case a free value for the tantamount of the critical density. Extendingthe dressed metric proposal to this phenomenological model, one might expect asimilar form for the associated primordial power spectrum.

Analytic Primordial Power Spectrum in the Dressed Metric Approach to Loop Quantum Cosmology and Thermodynamics of Spacetime