I will complete an MSc in physics, including a thesis, this year.

I have received an offer for a 9 month taught math master's course at Cambridge called Part III, although I don't yet have a funding offer for it, sadly. Some funding sources are available but it is competitive.

My main reason to take this course (beyond the degree itself) is to improve my chances of being accepted to a PhD in physics at Oxford or Cambridge.

Yet I also wonder how much this course is appreciated in the US and if having done it will improve my chances of being accepted for a PhD in top graduate physics schools there were I to apply there as well.

For my doctoral programme, I aim to research topics such GR, QFT, string theory, quantum gravity.

  • 4
    "Some funding sources are available but it is competitive." ─ Competitive, but worth competing for. The linked site says there are 30 scholarships available for international students; the course accepts about 250 students, but many of those will be UK students who wouldn't be competing with you for a scholarship. I would guess that you already overcame worse odds by receiving an offer at all.
    – kaya3
    Commented May 23 at 0:17
  • @kaya3: I don't doubt that OP is actively studying all funding options.
    – Trunk
    Commented May 23 at 10:27
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    @Trunk Please don't change the intention of posts by others. There are some exceptions when it's necessary to keep a post on-topic but OP is asking whether this course is appreciated in the US, not asking for financial advice. Your edit entirely changes the question focus.
    – Bryan Krause
    Commented May 23 at 13:47
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    @AnderBiguri It's an MMath for students who completed their undergrad at Cambridge, and a MASt for students who didn't. Cambridge doesn't award an MSc in Mathematics, and even the undergraduate course is a BA rather than a BSc.
    – kaya3
    Commented May 23 at 15:24
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    @kaya3 I know, I work there :) But Cambridge idiosyncrasies aside, its not materially different to an MSc in mathematics, that was my point. If you go to a different university and you get a BSc in Maths and then a MSc in Maths, you have an equivalent degree. Particularly to apply to a PhD. Of course, the name of the uni matters, I guess, and given how hard Part III is, im sure it helps. Also the difference between a BA and a BSc in mathematics is none, its an undergrad in maths. Particularly, again, when talking about PhD applications. Commented May 23 at 17:10

5 Answers 5


Part III of the Tripos is reasonably well known amongst professional mathematicians. I can't comment on physics. Good marks would surely boost your competitiveness for PhD slots in math.

Having taken one of Oxford's similarly pitched courses 8 years ago or so, here's a broadly applicable set of logistical anecdotes related to subsequent US PhD applications. They all flow downstream from the fact that Part III starts in October and US PhD applications are often due in December.

  • You will have to prepare and send off PhD applications alongside some of the hardest segments of the Masters course.
  • By the time PhD applications are due, you will have no marks from Part III nor will you have new recommendation letters because there is not enough time. The course is correspondingly unlikely to boost your PhD applications very much in the immediate term.
  • Thank you, can I also ask if you know whether part III or Oxford mathematical physics MSc will be more appreciated by universities? I tend to think that part III from information available online, but I would be happy to hear from someone who studied there
    – ziv
    Commented May 21 at 20:35
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    @ziv This site has a general rule not to rank programs etc., born out of reasoning that the Q&A format doesn't really handle this well. If you're an undergrad now, why not talk to a professor in your current program about these questions instead? On this particular point: I am a mathematician and took a math course at Ox, so I'm especially unable to guess what the physicists are looking for.
    – user176372
    Commented May 21 at 20:42

I am just finishing Part III after doing an MSc in my home country and my focus has been on the topics in theoretical physics that you listed. As others have pointed out, by the time applications are due, you will have no grades from the course since all assessment is at the end of the year. Therefore you are essentially trading on the reputation of the university alone. In the UK and Europe, Part III is held in high regard and so you will be at the top of the pack for PhD applications here but note that there are ~70 theoretical physics students in Part III so you'll be competing with them for the best places. Of those 70 students, ~10 get offers for PhDs in DAMTP HEP/GR and probably less for Oxford math HEP/GR (since you compete with more people outside Part III).

Having spoken to people in Part III who have applied for US PhD programmes, Part III will definitely help your chances, but there is still a large bias towards those who did their undergraduate at a reputable US institution. The only students I know who were accepted by a US programme had come from good US schools previously. This is only what I have observed from a small sample size and many in Part III just don't want to go to the US.

For what it's worth, I got everything I wanted out of Part III. It has been great training for a PhD in quantum gravity, the courses were awesome and I could trade on the reputation of the university to get the PhD position that I wanted. At the same time, I've found it really stressful. You begin the year worrying about PhD applications, then you work through the first holiday to prepare for the Cambridge PhD early offers test (HEP and GR only), then the rest of the year is spent worrying about getting the grades necessary to keep your PhD offer if you were lucky enough to get one.

Despite all that, doing Part III will most likely have a great impact on your career in theoretical physics or outside of physics and it really comes down to whether you can stomach the cost and a year of uncertainty.

  • Thank you very much for the useful information. Can I ask what skills you need to excel in the HEP/GR PhD exams? Do they check your overall understanding in physics and mathematics? Or do they specifically examine your skills in GR/QFT, relying on the fact that many students already have some background in these subjects? Is there a place where I can find more information on this exams?
    – ziv
    Commented May 22 at 15:52
  • Also, do you know how many of this ~10 successful PhD candidates get funding for the PhD?
    – ziv
    Commented May 22 at 16:03
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    I haven't seen any information on the early offers test online. It's entirely based on coursework in Michaelmas term. There is a question for each of the big theoretical physics courses (GR, QFT, Symmetries particles and fields, cosmology) and you answer 2 or 3 questions in 3 hours. Best way to start preparing would be to start looking at the course material. e.g. the QFT course is almost always based on David Tong's lecture notes which are publicly available.
    – Alex
    Commented May 22 at 16:06
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    I think funding is not a big problem for those who get offers in DAMTP HEP/GR but it can be a struggle for international students applying to other UK institutions.
    – Alex
    Commented May 22 at 16:07
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    When I took Part III exams (in 2010), the exams I took were all closed book, but exams for some of the other Part III courses which my classmates took were open book. I think an astrophysics or cosmology course was one example. I don't know how this is in 2024, but there is no long-standing strict rule preventing professors from setting open book exams.
    – kaya3
    Commented May 23 at 15:32

I am not qualified to say whether you are adequate in math already to undertake the type of research topic you favour at PhD level or not.

But rather than simply take the word of those providing the course - at a cost, naturally - I would encourage you to speak directly to professors covering your intended topics at Oxford (first) and Cambridge to get a feel for what's necessary here.

I expect that they will ask you on the extent of your familiarity in math areas relevant to the research level that they work at. So have full and honest answers ready. Expect them to also test the depth of your math knowledge too.

Bear in mind also that many graduate schools of physics offer - or at least loosely arrange with their math dept colleagues - supplementary courses for PhD students that may benefit from them. These are usually free of charge.

Good luck.


Where are you now? I am guessing not at either Cambridge nor Oxford. You will have a master in physics already in time but not from either of those universities(?). Do you want a second master in mathematics because that is what Part III is! Are you sure that your current course does not already covered those topics that you will be studying in Part III? There are options in Part III that you can always pick new courses to study, of course. Do you want the prestige of being attached to Cambridge or Oxford because if you don't have funding, it will cost you a small fortune for that. But then if there is a specific someone that you want to work with there, you should try communicate with that person to see how likely you can continue to do a Ph.D with him/her after Part III as well as the potential funding for the Ph.D.. It will be an obstacle course for you. If you can get the funding, then I would do the Part III especially if you can take new topics that have not been covered by your currnet course. On the other hand, if you cannot find any monetary support, then you will have to decide. I would say that it is still helpful with a Part III under your belt if you want to look for a Ph.D. position in the U.S afterwards.

  • Thank you, Yes I know it is another master's. Apart from my will to research with specific professors there, it cover topics that are almost not researched in my country at all. I am sure that this course really fits me well, but having to spend 50k pounds makes it hard to evaluate, so I am trying to understand if it has other benefits
    – ziv
    Commented May 22 at 13:25
  • £50k ? No way. That's Yale Law School fees.
    – Trunk
    Commented May 22 at 13:34
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    Yes... And the most frustrating thing is that I can study in my country for free with 2k pounds fellowship per month, the problem is that the research topics are not exactly what I want
    – ziv
    Commented May 22 at 14:10
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    @ziv: It highlights the one-way flow nature of the global brain drain: from poor continents to the rich ones. If academia were primarily about the spreading of enlightenment rather than the acquisition of distinctions we might see a significant counterflow. Look, you need to simply find the curriculum of this Part II course and then look for a PhD studentship in a physics department that endeavours to provide some or most of this curriculum on a free or low fee basis via that university's math department.
    – Trunk
    Commented May 22 at 22:42

As a physicist who has moved between the US and UK, and thus has experience with both systems, my advice is that part III (or the equivalent at Oxford) it not really a good idea if your main goal is to go to the US for a PhD.

First, there are the logistical issues, as user176372 mentioned in their answer.

Secondly (and most importantly), it may not help much, even if somehow you are able to use your part III results for your application to US PhD programs. The US and the UK actually have very different "cultures" when it comes to PhD admissions. The US is very research-focused: what matters most are projects that you've done, letters of recommendation from professors that you've worked with, and any publications you already have. The UK, on the other hand, is very coursework and exam-focused, probably a legacy of the tripos at Cambridge and the surrounding culture.

For example, performing very well (i.e. ranking top ~5 or so in your cohort) in Part III (or the equivalent at Oxford), will almost guarantee you a PhD position anywhere in the UK; but performing extremely well on courses/exams will not be a huge boost to a US PhD application, unless you have research experience to support it. In fact, doing a Part III (or the Oxford version) might be a net negative in terms of going to the US afterwards, since you will have to spend a whole year on classes with no time for projects or research.

Third, it could be a waste of time. Most US PhD programs have a required coursework component that cannot be (completely) skipped, even if you already have taken similar courses or already hold a Masters degree. Since you already have an MSc, if you do Part III + US PhD, you will end up basically doing three (!) masters in physics. This is not the best use of time: the only way to advance your career as a physicist is to do research: it is necessary to have basic knowledge foundation, of course, but after a point more coursework becomes a waste of time.

If you are dead-set on doing your PhD in Cambridge/Oxford, then go for the Part III. Otherwise, since you already have an MSc, it would be a better idea to apply to PhD programs in the US, and also in continental Europe. (Germany/Switzerland etc. are also great places to do a PhD in physics, and may be the best for you as it would allow you to directly get into research). You can also apply to PhD programs in the UK, although as you already know, your ability to get into Oxbridge might be limited by not having the Part III/masters—but it is not impossible; I know several people doing their PhD in theoretical physics in Oxbridge without having first done the masters from the same institution.

note: my field is condensed matter/quantum information theory. What I say here should apply to high energy theory as well. Pure math (and the parts of physics truly bordering on pure math) will be a bit different, as in there (I think) there is more emphasis on courses/exams/competitions, even in the US.

  • As a physicist who has moved between the US and UK ... Just to be clear for OP's benefit - did you do theoretical/mathematical physics or experimental physics ?
    – Trunk
    Commented May 24 at 11:30
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    @Trunk theory, but thanks for the reminder. see the edit
    – Aqualone
    Commented May 24 at 11:54
  • General Relativity, Quantum Field Theory, string theory, quantum gravity ... These are OP's preferred research areas. Can you comment at all on your post's likely relevance in regard to these ?
    – Trunk
    Commented May 24 at 12:48
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    I was going to write an answer, from the perspective of a high-energy theorist in the US, but this one already says what I would have said. Part III is certainly well-known, but (apart from the fact that you'll have barely started when you apply, unless you have a gap year in between) the downside is that we are mostly looking for research experience, and Part III doesn't help with that. Letters from the UK are often not useful because they just comment on relative rank in coursework, not research.
    – Matt Reece
    Commented May 24 at 18:45

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