Hubble Tension Reviewed

Posted in The Universe and Stuff with tags , , on November 24, 2023 by telescoper

Just a quick post to pass on a reference to a paper on arXiv (to appear in Annual Reviews of Astronomy and Astrophysics) about the ongoing saga of the Hubble Tension. The authors are Licia Verde, Nils Schöneberg, and Héctor Gil-Marín, three members of the ICCUB which is hosting me during my sabbatical. I saw an earlier draft of this paper but didn’t want to blog about it before the final version appeared. The abstract (which I’ve slightly reformatted) reads:

The Hubble parameter H0, is not a univocally-defined quantity: it relates redshifts to distances in the near Universe, but is also a key parameter of the ΛCDM standard cosmological model. As such, H0 affects several physical processes at different cosmic epochs, and multiple observables. We have counted more than a dozen H0‘s which are expected to agree if a) there are no significant systematics in the data and their interpretation and b) the adopted cosmological model is correct. With few exceptions (proverbially confirming the rule) these determinations do not agree at high statistical significance; their values cluster around two camps: the low (68 km/s/Mpc) and high (73 km/s/Mpc) camp. It appears to be a matter of anchors: the shape of the Universe expansion history agrees with the model, it is the normalizations that disagree. Beyond systematics in the data/analysis, if the model is incorrect there are only two viable ways to “fix” it: by changing the early time (z≳1100) physics and thus the early time normalization, or by a global modification, possibly touching the model’s fundamental assumptions (e.g., homogeneity, isotropy, gravity). None of these three options has the consensus of the community. The research community has been actively looking for deviations from ΛCDM for two decades; the one we might have found makes us wish we could put the genie back in the bottle.

arXiv:2311.13305


You can read the full paper here to learn about the scientific arguments, but I’d like to draw attention to this excerpt which is of more general relevance and with which I agree wholeheartedly:

It is also fair to say that the developments of the last decade have changed the expectations and modus operandi of a big part of the community. The community now expects results to be reproducible, hence the data and key software to be publicly available in such a way that a practitioner not involved in the original analysis could still retrace and reproduce all important steps and findings. While research areas such as the CMB and large-scale structure made this transition to “open science” about two decades ago, this was not the case for other areas of extra-galactic astronomy, but this is now changing.

arXiv:2311.13305

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Université de Montpellier

Posted in Biographical with tags , on November 24, 2023 by telescoper
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Université de Montpellier
The University of Montpellier is full of 1970s buildings but also has lots of trees behind which to hide them..

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Tour de France – Première Étape

Posted in Barcelona, Biographical with tags , on November 22, 2023 by telescoper
First Leg

I’m up reasonably early this morning to embark on the first leg of a visit to France. My first stop is at Montpellier on the French Riviera, where I’m giving a talk this afternoon at the Laboratoire Univers et Particules de Montpellier (LUPM) and will be staying for a few days before heading North to Paris and then back South again to Barcelona next week.

I’m looking forward to the trip as all three legs are on TGVs, which I’m told are comfortable, and I’ll hopefully get some nice views on the way. I’ve actually been to Montpellier before, to be on the jury for a PhD examination, but that was a long time ago and I don’t remember it very well.

Update: the travel went smoothly. It was a bit of an adventure getting the tram from Montpellier Saint-Roch railway station to the campus, and a bit more of an adventure navigating the building sites on the way to the seminar venue, but I got there in time and the talk went well. Now I have to find my hotel and then it will be necessary to consume alcoholic beverages.

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Signatories of DORA

Posted in Maynooth, Open Access, Science Politics with tags , on November 22, 2023 by telescoper

Following on from comments on a number of previous posts I just wanted to encourage anyone involved in research of any kind who hasn’t done so already to sign the San Francisco Declaration on Research Assessment (DORA) as an individual and if your institution hasn’t done so yet please encourage them to do so. You can check whether your organization has signed it here.

The Number One recommendation of DORA is:

Do not use journal-based metrics, such as Journal Impact Factors, as a surrogate measure of the quality of individual research articles, to assess an individual scientist’s contributions, or in hiring, promotion, or funding decisions.

San Francisco Declaration on Research Assessment

You can read the other recommendations for funders, publishers, institutions, and researchers, here.

I am well aware that some institutions have signed DORA but don’t really pay attention to it in their internal processes. Maynooth University is a signatory and certainly does take it into consideration when dealing with, e.g., recruitment and promotion but it, along with other signatories, has to deal with inconsistencies in the outside world. One of these is that, while Science Foundation Ireland and the Irish Research Council are both signatories of DORA, the Irish Government itself is not, so the Department of Further and Higher Education, Research, Innovation and Science is not bound by it. That makes no sense to me at all!

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SCOPUS SCOPUM

Posted in Open Access with tags , , on November 21, 2023 by telescoper

I’ve just spent the best part of two hours completing a lengthy and very tedious online form in order to apply to have the Open Journal of Astrophysics listed on Scopus. I did try this before, back in September, but the Scopus website crashed when I tried to submit the application. I emailed their helpline and they said they’d get back to me, but they never did.

One of the annoying things about the proposal form is the duplication of information. Almost every page requires the applicant to enter the name and email of the Managing Editor (that’s me). They could just carry that information forward from one page to the next.

An even more annoying thing is that one has to upload ten recent articles published by the Journal. It won’t accept weblinks, which would be more efficient for an online journal like OJAp. So I had to download ten papers from arXiv just to upload them again. Then I discovered they have a maximum file size of 10MB, which rules out several of our recent papers.

(All this reminds me that the next book on my reading list is Bullshit Jobs, by David Graeber…)

My personal feeling is that I couldn’t care less about getting listed by Scopus – which is run by racketeering publishing giant Elsevier as a gate-keeper for the academic publishing industry – but it seems that there are a lot of bean-counters around the world who think a journal isn’t a journal unless it is on their list, no doubt because Elsevier told them that is the case.

In fact it’s quite easy to look up citations, etc, for journals and individual articles without recourse to Scopus but administrators have been brainwashed into handing over large sums of money to Elsevier to inflate their already substantial profits. I don’t feel I should be asking for approval from the likes of them.

Anyway, the flakiness of their Scopus application platform – see paragraphs 1 to 3 above – does not fill me with confidence that Elsevier put much effort into the process. On the other hand, they have a captive audience so why should they? Now, however, at least I have an email confirming they received the application along with a tracking number and the statement

Please allow up to several months for the review process to be completed. 

The only reason for posting this here is to remind me to post if and when they respond. I won’t be holding my breath.

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Challenging the Standard Cosmological Model

Posted in The Universe and Stuff with tags on November 20, 2023 by telescoper

I have been asked to use the medium of this blog to transmit information about a forthcoming event at the Royal Society – that’s English for Real Sociedad – next April.

This is a scientific discussion meeting organised by Prof James Binney FRS, Dr Roya Mohayaee, Prof John Peacock FRS & Prof Subir Sarkar to be held from 15-16 April 2024, 09:00-17:00, The Royal Society, London SW1Y 5AG. Here’s a description:

Is the universe simple enough to be adequately described by the standard ΛCDM cosmological model which assumes the isotropic and homogeneous Friedmann-Lemaître-Robertson-Walker metric? Tensions have emerged between the values of cosmological parameters estimated in different ways. Do these tensions signal that our model is too simple? Could a more sophisticated model account for the data without invoking a Cosmological Constant?

The meeting is free to attend – both in-person and on-line attendance available. Advance registration is essential (an optional lunch is available to purchase during registration).

Meeting papers will be published in Philosophical Transactions of the Royal Society A.

For the full Chapter and Verse see the meeting website here.

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Thoughts of Retirement

Posted in Barcelona, Biographical, Maynooth, Open Access, The Universe and Stuff with tags , , , on November 19, 2023 by telescoper

I’ve been reviewing my situation while here in Barcelona. One of the themes that keeps popping into my head is well expressed by part of a little speech by Colonel Nicholson in The Bridge on the River Kwai:

But there are times… when suddenly you realize you’re nearer the end than the beginning. And you wonder, you ask yourself, what the sum total of your life represents. What difference your being there at any time made to anything – or if it made any difference at all, really. Particularly in comparison with other men’s careers. I don’t know whether that kind of thinking’s very healthy, but I must admit I’ve had some thoughts on those lines from time to time.

Healthy or not I’ve also had thoughts along those lines, and sometimes feel I should step aside and create a job opportunity for someone younger. I know my employer wouldn’t mind if I did that either. They’d much prefer replacing me with someone cheaper and more compliant than me. I think if I asked for early retirement they would probably jump at the chance. I’d miss the teaching and the students, of course,

The fact of the matter is though that I can’t afford to retire yet. I have a mortgage to pay and I’ve only had five full years of pensionable service in the Irish system, so won’t get much of a pension. I have the frozen residue of my UK pension, of course, but that is subject to an actuarial reduction if I take the benefit before I’m 65, which is also the standard retirement age for academic staff in Ireland. I can’t be made to retire here until I’m 70, in fact, but I think I’ll be well beyond my best-before date by then and am not keen to overstay my welcome.

So it looks like I’ll have to stay until I’m 65 at the earliest. In fact I won’t be able to collect the State Pension (SPC) until I’m 66, so I’ll probably have to stay another year. That means that when I get back from sabbatical I will have four or five years left until I can retire. I don’t know what I’ll be teaching when I return but I hope I get a chance to teach a few new modules before the end. In particular some cosmology or astrophysics would be particularly nice. All this is predicated on: (a) me living long enough; and (b) Physics at Maynooth not being closed down; neither of these is certain.

When I moved to the Emerald Isle in 2017 I supposed that I would carry on living in Ireland after retiring. Now I’m having some doubts about that. I have been advised by medical experts that my arthritis would be more tolerable in a warmer climate. And there’s the cost of living in Ireland, which is much higher than Spain. I can imagine living here, actually, though I think Barcelona itself might be a bit expensive for a pensioner. Somewhere in the surrounding countryside, or along the coast, might be nice. I’ve got a few years to think about that.

Another thing in my mind is what will happen to the Open Journal of Astrophysics when I retire? I would like some larger organization or community to take it over in the long term. It’s not expensive to run, actually, but someone would have to take over as Managing Editor. Moreover, I don’t think it’s really fair to expect one small University in Ireland to bear the full cost of a global astrophysics journal indefinitely.

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The Little Book of Irish Research

Posted in Euclid, Maynooth, The Universe and Stuff with tags , on November 18, 2023 by telescoper

Yesterday, the last day of Science Week, saw the launch by Simon Harris TD, Minister for Further and Higher Education, Research, Innovation and Science, of the Little Book of Irish Research. This book, which is aimed at school students, so is written at an elementary level, gives quick summaries of areas of research that the general public said that they were interested in, grouped into sixteen themes, and it will be distributed to schools all round Ireland.

I was very gratified to see myself get a mention (on page 41), though it’s not really about me but about Euclid which has generated considerable interest in the general public already and is set to continue doing that for many years. As you can see, there’s also a double-page spread of JWST, though unfortunately it does not name the scientists involved; Paddy Kavanagh is the main man at Maynooth for matters JWST.

I understand The Little Book of Irish Research will be the focus of a social media campaign over coming weeks, which will hopefully make more people more aware of the research going on in all disciplines in Ireland. I think we’ll find it useful for our own outreach events, open days, etc, in the Department of Theoretical Physics, and so will the many colleagues in other Departments whose work is also featured.

I haven’t seen hard copies of the book yet, as I’m in Barcelona, but if you want to read it here is a PDF file of the whole thing for you to download at your leisure.

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New Publication at the Open Journal of Astrophysics

Posted in mathematics, OJAp Papers, Open Access, The Universe and Stuff with tags , , , on November 17, 2023 by telescoper

It’s Friday afternoon but before I collapse, exhausted, into the arms of the weekend I’ll take  the opportunity to announce yet another new paper at the Open Journal of Astrophysics.

The latest paper is the 45th so far in Volume 6 (2023) – just five to go for a half-century – and it’s the 110th altogether. This one was actually published on Tuesday November 14th.

The title is “Marginalised Normal Regression: Unbiased curve fitting in the presence of x-errors” and it’s by Deaglan J. Bartlett (Institut d’Astrophysique de Paris, France) and Harry Desmond (Portsmouth, UK). It sounds like a statistical methods paper, and indeed it is, but remember that there’s a very long historical connection between astronomy and the development of statistical methods for data analysis, and this paper tackles a very longstanding issue: how best to fit curves in the presence of noisy data. This paper presents a new method for doing this, together with applications to cosmological and astrophysical data, and accompanying software. It is in the folder marked Instrumentation and Methods for Astrophysics.

Here is the overlay of the paper containing the abstract:

You can click on the image of the overlay to make it larger should you wish to do so. You can find the officially accepted version of the paper on the arXiv here.

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The Magician by Colm Tóibín

Posted in History, LGBTQ+, Literature with tags , , on November 17, 2023 by telescoper

Continuing my attempt to catch up on a backlog of reading I have now finished The Magician by Colm Tóibín. A couple of years ago I attended a Zoom event featuring the author Colm Tóibín talking about this book, which is a fictionalised account of the life of Thomas Mann. It’s taken me a ridiculous long time to get round to it, but it was worth the wait.

The life of Thomas Mann was colourful, to say the least. Born in the German city of Lübeck in 1875, Mann’s father was a wealthy merchant and his mother was from Brazil. His elder brother Heinrich Mann was also a novelist essayist and playwright of considerable reputation. Despite his barely concealed homosexuality, Thomas Mann married Katia Pringsheim in 1905, his wife seemingly not minding about his sexual orientation. He led a comfortable life until he began to see the signs of the coming descent of Europe into the First World War. He was awarded the Nobel Prize for Literature in 1929 and went into exile from Nazism in 1933, becoming an American citizen in 1944. In the post-War McCarthyite era he was made to feel less welcome in the USA for having visited East Germany and consequently under suspicion for communist sympathies. Not wanting to return to Germany, he spent most of the last years of his life in Zurich. He died in 1955 at the age of 80.

In some ways this work is reminiscent of The Dream of the Celt which I reviewed a few weeks ago, in that it’s a fictionalised biography, based partially on material found in diaries and with a theme of (partly) suppressed same-sex desire; several of his six offspring were gay or bisexual too. On the other hand I don’t think it’s accurate to think of this book so much as a biography of Thomas Mann but more of a biography of the late 19th and early 20th Century with Mann as the lens. In fact I finished the book without feeling that I knew very much at all about Thomas Mann’s character and personality. That’s probably deliberate as he seems to have cultivated an air of mystery surrounding himself. We follow Mann and his large family through the events leading up to both World Wars, and the effect these tumultuous times had on his siblings and offspring. His family endured more than its fair share of tragedy, with multiple suicides and other heartbreak.

An interesting aspect is the collection of little character sketches this book gives us of famous people with whom Mann interacted in his life. Mann was himself very famous indeed both in Europe and America. Tóibín gives us (not always flattering) views, through Mann’s eyes of, among many others: Gustav Mahler, Albert Einstein, Eleanor Roosevelt, Arnold Schoenberg, Christopher Isherwood and W.H. Auden. Incidentally, Auden married Mann’s daughter Erika so she could get British citizenship; the marriage was never consummated.

It’s a beautiful book, written in a style that frequently seems to mimic Mann’s own prose. Juxtaposing the ideas in his novels with the events happening when they were being written, both within his own family and in the wider world, provides fascinating insights. I have only read a couple of Thomas Mann’s books: Death in Venice and The Magic Mountain. Knowing more about his life, I now want to read these again and also read the others.

And so as one book disappears from my reading list, several more appear…

P.S. This is the novel in which the Mann family sits around listening to a gramophone record of In fernem Land sung by Leo Slezak I mentioned a few days ago.

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