some of you will have registered for the short Machine Learning (ML) course that we are planning to give, starting next week. ML is best "learned" by doing it, so we are planning to use the computer room E4.28 for exercises during all the lectures. But we think you might also find it more useful if you were to bring your laptops along and install+run the ML codes there.
 We are expecting to run all the ML on a Ubuntu installation (Francois Chollet, one of the key people in the field, says "it’s possible to use Windows, too, but I don’t recommend it"). Other Linux installations should also work. If you only have Windows, Rudo recommends installing
with a Ubuntu 19.10 installation (http://releases.ubuntu.com/19.10/).
 During the course, we intend to offer you downloadable ML source codes via Rudo's blog at
where you can also see a copy of this email. The direct download link is in the first entry of the blog and given here as well, i.e.
 We want to share literature on ML with you using Mendeley, i.e. https://www.mendeley.com/. Although the Mendeley Desktop might be convenient to install (we have it on our machines), the online interface could be ok for the course. But in order to "share" PDFs with you, you need to have a (free) Mendeley account. Please create one.
 Last, we, Djena and Rudo, are both new to ML, so this will be a course where we will all explore ML together! We hope you'll enjoy it.
- Rudo and Djena
December 06, 2019
December 05, 2019
June 09, 2019
Writing about web page https://www.journals.elsevier.com/physica-e-low-dimensional-systems-and-nanostructures
In my editorial work, I often encounter manuscripts in which authors are using more or less well-established numerical software packages to produce scientific results. These software packages may sometimes be of a commerical nature or already have a long development history. Typical examples of such codes are VASP, COMSOL, CASTEP, Siesta, GROMACS, etc.
Usually the authors of the manuscript are not developers of the software packages and simply use them as is. There is of course nothing wrong with this. However, in some case, these manuscripts contain (i) results only calculated for a single set of input settings, (ii) give numerical data without any indication of the accuracy of these estimates and/or (iii) any indication as to how these data are sensitive to the chosen parameter settings.
To be concrete, image a numerical DFT study of a certain material under strain and the determination of one of its lattice parameters as "a"=3.1234. Clearly, in many codes this number will depend on, e.g., the chosen ernergy cut-off as well as the number of k-points used in its basis set. In order to ascertain the accuracy of the chosen value for "a" one could, e.g., increase the number of k-points and observe how much "a" changes. Similarly, "a" usually changes when the cut-off energy changes, say from 500meV to 700meV. Both changes result in a new value for "a", say "a"= 3.1500 from the new energy cut-off and 3.1034 from the changes in chosen k-points. Indeed, one can usually get other values by chosing other k-point meshes and larger energy cut-offs. Hence the quoted final result should be something like
"a"= 3.1234 +/- 0.03 +/- 0.02 = 3.12 +/- 0.05
accompanied by an explanaton as to how these error bars were obtained. Only with these error estimates can readers of a scientific article see how accurate the data really is and how stable to variations in input parameters. Note that these values are still subject to further sources of error due to, (i) other input parameter dependencies and (ii) systematic errors that might be present in the chosen software package itself. Nevertheless, as given above, the bold final result at least provides some insight into the validity of the quoted numbers.
September 03, 2018
Writing about web page https://www.journals.elsevier.com/physica-e-low-dimensional-systems-and-nanostructures
As editor of Physica E, I often receive letters from younger colleagues asking to be considered as reviewers for the journal. My answer to this is usually as given below:
Thanks a lot for your interest in joining the Physica E pool of reviewers. Indeed, we are always keen to enlarge our group of experts to go out for a review. One of our key criteria is that these colleagues are known authors themselves in the field of specialization and have a publication record in the Physica E areas of excellence, i.e. nanostructures and low-dimensional systems. This excellence and engagement with Physica E’s research areas is usually best supported by previous publications in Physica E.
You can join our peer review pool by registering in EVISE to start the process, i.e.
In EVISE, as soon as a person registers in the system, they become available as reviewers; however, they will be able to access their reviewer profile/account of a journal only when they are invited by the journal for the review process.
February 20, 2018
A comment on https://www.thetimes.co.uk/edition/news/university-strike-puts-final-exams-in-danger-l27b9x7vn
This is a fairly reasonably written article, thanks for that to "The Times". Some of the comments made by members of the public are rather less so.
VC pay is certainly a point that received attention recently, but it is not the main issue here. The UK university landscape is booming, but that has not resulted in marked increases in staff pay. On the contrary, the original final salary pension scheme, run by USS until 2016, that most academics joined at their universities, was downgraded to a less attractive defined benefits scheme (DBS) to make it "stable". Let me also point out that in distinction to most non-academic careers, lecturers will routinely spend years (~10) of their early employment in further study, fixed-term situations and fellowships, many of which do not result in pension-eligible contributions, before landing that first permanent employment (and many never do). A simple comparison with the "private sector" is hence missing the point. The reward for lecturers until recently was a "lowish" salary coupled with a good pension.
Some comments correctly ask why the previous scheme now seems in trouble. The question for academics is slightly different: why should they now trust a proposed defined contributions scheme (DCS), where you pay without knowing what you get, when the track record of the current USS scheme is so dismal? Furthermore, the current deficit is an actuarial one: for the purpose of the pension fund, all participating universities are assumed to be part of a single "company" and the "risk" to the pension fund is one in which all these places go bust at the same time. Times readers will know that this is a highly unlikely scenario (I do not know a case when this has ever happened).
Some commentators are correctly unhappy about the possible impact on student education and progression. As lecturer, I fully agree. As employee at a university, I am faced with effectively a substantial (future) pay cut by my employer. Hence it is my employer, the university, who has decided not to pay for the lectures (and the marking, the supervision, the tutorial/pastoral care, the work done in research, etc.). Let me also note that students have overwhelmingly joined forces with lecturers in this dispute.
Last, but not least, perhaps it is useful to point out that the universities involved in the current strike action are the older, more research active universities, i.e. many of the crown jewels of the UK university system. The younger universities of the post-90 age are part of the largely taxpayer-funded "teacher pension scheme" (TPS). Colleagues in that scheme tell me that their pensions are expected to be better than what USS will provide. The TPS scheme still contains elements of final salary and career-averaged benefits (since 2015).
May 09, 2017
This is the reponse received via Mr Dalton's letter to the Secretary of State for Exiting the European Union (formatting is mine, but closely follows the original PDF):
3 May 2017
MR RUDOLF ROEMER, 17 THE RIDGEWAY, WARWICK, WARWICKSHIRE, CV34 5SH
Thank you for your letter of 24 April, regarding the UK's decision to leave the EU. I am responding on behalf of the Secretary of State.
Mr Roemer has raised a number of concerns, which I will answer in turn.
The Prime Minister underlined in her letter to the President of the European Council that we should seek an early agreement on the rights of UK nationals in the EU and EU nationals in the UK on a reciprocal basis. We have been clear that we should always put citizens first. This is a priority issue for the forthcoming negotiations.
We remain full members of the EU for the next two years, and subject to all the rights and obligations of membership. There will be no change to the rights and status of EU nationals living in the UK, or UK nationals living in the EU, while the UK remains in the EU.
The arrangements in relation to the movement of EU citizens into the UK after exit are, of course, matters that the Home Office is currently looking at, and they will be subject to discussion by Parliament.
We want to reach an agreement as early as possible. As soon as the other Member States have agreed the negotiating mandate for the Commission we want to start discussing this issue.
Please let me reassure your constituent that EU nationals who have lived continuously and lawfully in the UK for at least 5 years automatically have a permanent right to reside. EU nationals also have the right to reside in the UK with their family members and be treated equally to UK nationals if they are studying, working, self-employed or self-sufficient.
EU nationals who have lived continuously and lawfully in the UK for at least 6 years are eligible to apply for British citizenship if they would like to do so.
The UK will remain an open and tolerant country, one that recognises the valuable contribution migrants make to our society and welcomes those with the skills and expertise to make our nation better still.
Social Security Benefits and Pension
The UK State Pension, along with other social security benefits is payable based on the UK National Insurance contributions that have been paid. Nationality or citizenship does not form part of the criteria for the award of State Pension.
Access to Education
The UK will always welcome genuine students and those with the skills and expertise to make our nation better still. We have already confirmed that existing EU students and those starting courses in 2016-17 and 2017-18 will continue to be eligible for student loans and home fee status for the duration of their course. We have also confirmed that research councils will continue to fund postgraduate students from the EU whose courses start in 2017-18.
The Government also recognises the important contribution made by students and academics from EU Member States to the UK's world class universities. A global UK must also be a country that looks to the future.
Please pass on my thanks to your constituent for taking the time to write and I hope that this answers Mr Roemer's questions.
RT HON DAVID JONES
MINISTER OF STATE FOR EXITING THE EUROPEAN UNION
Follow-up to Reponse by Daniel Dalton MEP (and Anthea McIntyre MEP) from Rudo's blog
Today I received a reply from Mr Dalton's contact to the UK government (formatting removed, "copy of the reponse" in next follow-up):
Dear Mr Roemer
Further to my last email of 12th April 2017, you recall I sent a copy of your email to the Secretary of State for Exiting the European Union.
As promised, I enclose for your information a copy of the response that I have received from the relevant Minister.
Daniel Dalton MEP
Conservative MEP for the West Midlands
Tel: 01926 930683
Twitter - @ddalton40
April 20, 2017
April 10, 2017
Mr Chris White
MP for Warwick and Leamington
10 April 2017
Dear Mr White,
Let me introduce myself as Professor of Physics at the University of Warwick and a German citizen. I hold 3 doctorates from three different universities in 3 countries. My research experience has spanned three continents (USA 1989–1990, 1992–1994, India 1994–1995, Germany 1996–2002, UK 2002–present, China 2015-present). I am author of more than 160 scientific publications, have given more than 140 invited talks and made more than 80 conference presentations. I am Co-Editor of various scientific journals, serve as secretary and treasurer of the Institute of Physics’ Theory of Condensed Matter group, am external under- and postgraduate course examiner at UK and international universities, regularly review UK, EU and international grant proposals and have thus far organized 20+ conferences with national and international remit.
I am, I hope you agree, one of the those “highly skilled European workers” that the UK government wants to attract and retain after the recent decision to leave the EU by 2019. Let me therefore take this opportunity to outline to you what I expect to happen in the UKs negotiations with the EU for me to continue to consider the UK an attractive place to work and live. I hope that you will find the letter instructive since I think it highlights some of the complexities associated with the decision to leave the EU. I will concentrate purely on my personal family circumstances and note that the issue of the UK’s continued involvement in the EU’s research area has been brought to parliament’s attention by various previous routes.
In order to be specific, let me state that our family came to the UK in 2002 after I had been offered an academic position at Warwick. We accepted the offer particularly because of the attractiveness of an academic position inside the EU. My wife originates from a non-EU/EEA country and our daughter was 2 years old at the time of our arrival in the UK. We own a house (via a mortgage) in Warwick.
- At present, we reside in the UK due to the applicable EU treaties on free movement. I understand that these are likely to cease being applicable from 2019 onwards. It is therefore mandatory that the shape of any new residency regulations is being made public as soon as possible. I travel regularly, mostly work related, and it must be clear at least one year in advance of the UK’s leaving the EU in 2019 what other residency regulations will be put in place. If, for example, the UK would want current EU residents to apply for residency status under current or any future regulations, then this must be made clear as soon as possible. I note that no such guidance has been offered thus far, leading to contradictory and misleading advice from immigration lawyers. Let me also state that the current 85-page residency application document of the Home Office is not fit for service and its online version does, for example, not apply to my wife nor my daughter.
- I hope it is not necessary to point out that by leaving the EU, the UK has put itself in direct worldwide competition for academics with other countries. To illustrate the point, I am writing this letter while on a visiting professorship at a Chinese university.
- I would expect to being able to continue to work in the UK under the same conditions as of now. I would not want to be made to reapply to my current position as part of any home office “crackdown on immigrants”, nor would I want to be subject to lengthy paperwork simply to continue doing the work I am already doing.
- My wife has been enjoying a full work permit since we came in 2002. She only started to work once our daughter was somewhat older, but she now regularly works in the local schools in the Warwick and Leamington Spa area. We would clearly expect her to be able to continue to work in the UK from 2019 onwards.
- In the initial years at Warwick, we received child benefit, but no other social benefits. After 15 years in the UK, with all taxes, national insurance, etc. paid, I expect that my family will be able to enjoy all benefits of a UK national in a similar situation. This is, in particular, in the hopefully unlikely situation, that we would need to apply for jobseeker and/or similar such benefits in the future.
- We currently enjoy full access to the NHS’ services. I had little need to use these until a motorbike accident last year. I would expect that we will continue to have full access to the NHS without additional payment or restrictions.
- Furthermore, as part of the current EU membership privileges of the UK, were we to move back to Germany, our contributions to the UK’s social benefits would be counted towards any potential such benefits in Germany. I would expect that this agreement continues to be honored by both sides after 2019.
Access to education
- Our daughter is currently in her penultimate year at A level, set to graduate in 2018. She will then look for a place at a university. At present, we are considering UK, German and other EU universities. She has a German but no UK passport. We are now concerned that (i) she might have to pay higher university fees in the UK if she were to stay here. Or, (ii) if she were to go and study in the EU, whether she will be able to return to the UK after her 4-5 years abroad? Obviously, we feel strongly that being able for our daughter to continue to come back to the UK after her studies abroad is a crucial issue determining our future in the UK as a family.
- We do enjoy living in the UK at present. However, upon retirement in 15+ years, we might very well want to return to Germany or indeed, my wife’s home. At present, EU regulations safeguard my pension rights in Germany and the UK. I would want to see that these regulations are being kept and safeguarded for any current EU national in the UK.
- In order to contribute towards my family’s financial security and to supplement our retirement, I have been contributing to a life insurance in Germany since the mid-1990s. It is my understanding that it is current EU law which enables insurance providers to offer their services across EU boundaries. I fear that the insurance company might take the opportunity to cancel the contract when the UK leaves the EU in 2019 (which would be financially beneficial to them). I am therefore asking you to make sure that such existing contracts are being safeguarded in the Brexit negotiations.
Citizenship and disenfranchisement
- Until now, we EU citizen in the UK were welcomed as fellow EU citizen, giving us shared rights and responsibilities. I fear that upon leaving the EU, we will revert to being “foreigners”, or, indeed, “immigrants”. It must be clear that for people with choice of their destination, this is not an acceptable long-term situation. The UK should therefore think hard and innovatively about a way to make such people welcome. If we were to be offered, for example, a quick and easy route to UK citizenship, we would most likely take it. However, the present such system is not attractive as it seems designed to keep people out rather than to welcoming them in.
- The current 3 million EU citizen in the UK are most likely to stay in the UK at least in the short-term. This is already clear from the UK’s need to safeguard its own citizen now in the EU. However, the long-term perspective is less clear. Allow me, as a German national, to suggest that Germany’s treatment of its own, mostly Turkish, immigrant population has not been beneficial to either party. In particular, Germany’s reluctance to grant quick and easy access to citizenship status has led to a core of disenfranchised German-born nominally non-Germans living somewhat isolated in the heart of Germany. The UK would do well to avoid this trap. In this context, I would find it useful if continued voting rights in local elections could be extended to EU citizen in the UK. It is practice at present, has led to no discernible loss of democracy or large-scale local power shifts that I am aware of and is a great way to engage EU citizen in their local communities. Indeed, my wife, as citizen of a Commonwealth country, enjoys already much more inclusive voting rights.
- I have been distressed that, after the Brexit vote last year, parliament has yet to engage with EU citizens in the UK in a broad and inclusive manner. While much importance had been attached to calls for evidence from parliament on the impact of the Brexit vote for UK businesses, UK financial services and UK higher education institutions, I am yet to see a proactive initiative by parliament and, indeed, you as a local MP, to directly engage with the 3M EU citizens currently in your care. This lack of interest does not bode well for the future.
The UK decided to leave the EU. I respect that decision although I did not wish for it to happen. It is now the UK’s responsibility to make sure it has an offer in place to make it attractive for my family to remain after 2019. Such an offer should be in place soon. We will of course follow the EU-UK negotiations with interest, but our family’s future will be decided by how quickly, fairly and welcoming the UK engages with us as current residents and, hopefully, valuable assets it wishes to retain.
Rudolf A Roemer
PhD, Dr. rer. nat. habil., DSc, FInstP