The rate at which the universe is expanding, known as the Hubble constant, is one of the fundamental parameters for understanding the evolution and ultimate fate of the cosmos. However, a persistent difference called the “Hubble Tension” is seen between the value of the constant measured with a wide range of independent distance indicators and its value predicted from the big bang afterglow.
On March 22, 1909, US-American physicist Nathan Rosen was born. He is best known for his cooperation together with Albert Einstein and Boris Podolsky on the quantum-mechanical description of physical reality leading the the so-called Einstein-Podolsky-Rosen paradoxon, as well as his postulation of worm holes connecting distant areas in space. Although purely theoretic, his work also had an important impact on science fiction literature.
Results derived from data obtained by Wilkinson Microwave Anisotropy Probe (WMAP) are extensively used in many areas of physics. It has been claimed recently that the published WMAP calibrated data and maps might be in question because of an undocumented timing offset in the official processing pipeline [The origin of the WMAP quadrupole, Hao Liu, Shao-Lin Xiong, Ti-Pei Li]. This timing error was shown to induce a quadrupole pattern in the final maps that is very similar to the officially published quadrupole mode. It is clear that a timing offset at the map-making stage will strongly affect the quadrupole scale, since the map-making in [The origin of the WMAP quadrupole, Hao Liu, Shao-Lin Xiong, Ti-Pei Li] was based on the official WMAP calibrated TOD. But there is also a possibility that the calibration process itself could be affected as well and we test this here. In this work we approximately reproduce the original dipole-based iterative calibration procedure to produce a calibrated data set starting from raw uncalibrated data. Using the calibrated data we generate a set of sky maps that we compare to the officially released maps and note some differences between our and official results. We also investigate the effects of various timing offsets introduced in the calibration stage on the final products. We find that a timing offset in the calibration process has little effect on the calibrated data and induced quadrupole.
Sir Fred Hoyle, born in 1915 was a famous astronomer, mathematician, and author. The scientist was the first to coin the term "Big Bang" for the now prevailing theory of the early development of the universe in 1949, even though he happened to be a strong opponent of this theory.
S. Vagnozzi. (2023)cite arxiv:2308.16628Comment: 39 pages, 18 sub-figures arranged into 11 figures, most of which reproduced (with permission) from other works, many references, älone" is the keyword here. A very pictorial summary of the whole paper is in Fig. 11, not made by me. Accepted for publication in Universe as an invited opinion/review paper in the special issue "Modified Gravity Approaches to the Tensions of Łambda CDM".
G. Domènech. (2023)cite arxiv:2307.06964Comment: Lectures notes prepared for the ICCUB School 2023 on Primordial Black holes in the University of Barcelona. Comments and corrections are welcome.
F. Leclercq, and A. Heavens. (2021)cite arxiv:2103.04158Comment: 6+8 pages, 4+5 figures. Matches MNRAS Letters published version. Appendices provide supplementary information, including calculations of Fisher matrices. Our code and data are publicly available at https://github.com/florent-leclercq/correlations_vs_field.
S. Hutschenreuter, S. Dorn, J. Jasche, F. Vazza, D. Paoletti, G. Lavaux, and T. Enßlin. (2018)cite arxiv:1803.02629Comment: 14 pages, 19 figures. Revised version after peer review. Scientific and computational results are unchanged. This is an author-created, un-copyedited version of an article published in Classical and Quantum Gravity. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. This article is published under a CC BY licence.
E. Grohs, and G. Fuller. (2023)cite arxiv:2301.12299Comment: Short review on Big Bang Nucleosynthesis for the Handbook of Nuclear Physics. 23 pages, 2 figures.
D. Huterer. (2022)cite arxiv:2212.05003Comment: Invited review for The Astronomy and Astrophysics Review, aimed at a non-expert; 29 pages + references.