Archive for nucleosynthesis

Cosmology Talks: James Alvey on Big Bang Nucleosynthesis in 2021

Posted in The Universe and Stuff with tags , , , , , on October 15, 2021 by telescoper

It’s been a while since I last shared another one of those interesting cosmology talks on the Youtube channel curated by Shaun Hotchkiss. This channel features technical talks rather than popular expositions so it won’t be everyone’s cup of tea but for those seriously interested in cosmology at a research level they should prove interesting. I found this one particular interesting as it is a field that I lost track of quite a long time ago and it was great to see what has been going on!

Here James Alvey gives a pedagofical overview of the general state of the field of Big Bang Nucleosynthesis (BBN) in 2021, including the basic physics that goes into BBN calculations through each of the relevant epochs (neutrino decoupling, the deuterium bottleneck, etc). He gives particular emphasis to the recent LUNA measurements of the D + p →γ + 3He reaction (or deuterium + proton goes to photon and 3-Helium). This was previously the source of greatest uncertainty in predicting the final deuterium abundance of BBN. He ends by talking about the implications of the LUNA measurements on possible new physics beyond the standard model, in particular possible thermal relics.

There is a Nature paper about the LUNA results here and  two other papers on this topic by James can be found here and here.

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New Publication at the Open Journal of Astrophysics

Posted in OJAp Papers, Open Access, The Universe and Stuff with tags , , , , , , , on February 2, 2021 by telescoper

Time to announce the first publication of 2021 in the Open Journal of Astrophysics. This one was actually published a few days ago but  it took a bit of time to get the metadata and DOI registered so I held off announcing it until that was done.

The latest publication is a lengthy and comprehensive review article (67 pages altogether) by Allahverdi et al. which has 26 authors from all round the world. It is entitled The First Three Seconds: a Review of Possible Expansion Histories of the Early Universe and is a study of the various possible evolutionary histories of cosmic expansion possible with a wide range of cosmological models with their implications for baryogenesis, nucleosynthesis, primordial gravitational wave production, and many other things besides.

Here is a screen grab of the overlay:

You can click on the image to make it larger should you wish to do so. You can find the arXiv version of the paper here. This is one for the Cosmology and Nongalactic Astrophysics folder.

And so Volume 4 begins. Volume 3 had 15 papers, Volume 2 had 12 , and Volume 1 just 4 so we’re growing slowly but surely! Let’s see how many we publish in 2021. I can tell you  we have some very exciting papers in the pipeline…

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