2020/05/19 by Herbert W. Hamber, Lu Yu, Hamber, Herbert W. +3
Earth and Planetary Sciences · Physics and Astronomy · #Cosmology and Gravitation Theories #Cosmology and Nongalactic Astrophysics (astro-ph.CO) #FOS: Physical sciences #General Relativity and Quantum Cosmology (gr-qc) #Geophysics and Gravity Measurements #Relativity and Gravitational Theory
paper · pdf · doi:10.48550/arxiv.2005.09720
openalex publication_date 2020/05/19 · openalex created_date 2022/07/26 · openalex updated_date 2026/07/28
Power spectra play an important role in the theory of inflation, and their\nability to reproduce current observational data to high accuracy is often\nconsidered a triumph of inflation, largely because of a lack of credible\nalternatives. In previous work we introduced an alternative picture for the\ncosmological power spectra based on the nonperturbative features of the quantum\nversion of Einstein's gravity, instead of currently popular inflation models\nbased on scalar fields. The key ingredients in this new picture are the\nappearance of a nontrivial gravitational vacuum condensate (directly related to\nthe observed cosmological constant), and a calculable renormalization group\nrunning of Newton's G on cosmological scales. Results obtained previously were\nlargely based on a semi-analytical treatment, and often suffered from the\nlimitations of various approximations and simplifying assumptions. In this\nwork, we extend and refine our previous calculations by laying out an updated\nand extended analysis, which now utilizes a set of suitably modified\nstate-of-the-art numerical programs (ISiTGR, MGCAMB and MGCLASS) developed for\nobservational cosmology. As a result, we are able to remove some of the\napproximations employed in our previous studies, leading to a number of novel\nand detailed physical predictions. These should help in potentially distinguish\nthe vacuum condensate picture of quantum gravity from that of other models such\nas scalar field inflation. Here, besides the matter power spectrum P(k), we\nwork out in detail predictions for what are referred to as the TT, TE, EE, BB\nangular spectra, as well as their closely related lensing spectra. However, the\ncurrent limited precision of observational data today (especially on large\nangular scales) does not allow us yet to clearly prove or disprove either set\nof ideas.\n