Prospective grad?

Introduction

This particular web essay is intended for university students interested in doing a PhD in string theory in the Department of Physics at the University of Toronto (locally known as “UofT”, pronounced “you of tea”). Much of this information should also be useful to students interested in particle theory or early universe cosmology.

Please note that all e-mail enquiries regarding admissions requirements and/or general aspects of supervision should be directed to the Graduate Office, not to me. Email questions which are specific to my expertise or to doing a PhD in my research group are the ones to which I am happy to respond in detail.

Thinking of applying?

If you are interested in coming to UofT for a PhD, then you should start by browsing our Physics Department web pages, especially our graduate studies section which contains important application information. Please make sure that you submit your complete dossier before the January deadline: late applications may not receive full consideration. (Note: new students must start their program in Fall term; we do not have an admissions intake for starting in Winter/Spring term.) The admissions committee will then review your dossier. In our high-energy theory group, we are always on the lookout for smart students interested in working with us.

Like other good departments worldwide, UofT Physics is strongly commited to excellence and equity and therefore has written policies and procedures that ensure fairness in graduate admissions. The basic principle is that every potential PhD student should have equitable merit-based access to potential PhD supervisors. Decisions on whom to admit to our program are made by a committee of professors representing various areas of physics, on the basis of merit. Attempts to influence this process via personal appeals to individual profs like me are unlikely to succeed: if you know one of our faculty well enough for them to comment meaningfully on your abilities, then you should ask them to write you a recommendation letter. Overall, if your application is an excellent one, then it will stand out on its own merits.

In considering where to apply to PhD programmes, a good rule is that you should be interested in working with at least three professors in the department of interest, and preferably more. It is unwise to set your heart on working with any one professor – here or anywhere else. For instance, through no fault of your own, your professor of choice may have zero new advisory capacity when you arrive. Equally, any professor may be different in real life than how they appear in the abstract or on the web.

You have clearly already found my home page. Note that we also have several other profs here doing forefront research in high-energy theory and particle experiment. My closest colleagues are Prof. Erich Poppitz, a particle theorist who has also worked on string theory in the past, and particle theorists Prof. Bob Holdom and Prof. Michael Luke. More generally, our physics department has tons of exciting and fascinating areas of research, and cognate departments and institutes are very strong: see also the Mathematics Department, the Fields Institute, the Canadian Institute for Theoretical Astrophysics (CITA), and the Astronomy Department home pages.

Supervision generally

In our group, we do not expect Masters (or Direct-Entry PhD) students to match up with thesis advisors before arriving. Our overall graduate program structure is deliberately designed to allow you to think and learn for a bit before settling this all-important issue. That said, we also strongly encourage you to start discussing possibilities early in your first academic term here. Procrastination never pays off. (Please see the choosing your research advisor section of our graduate handbook for details.)

The basic point is that you need to have significant discussions with potential advisors – and their current students – so you can learn precisely what they research and how they work with research students. Any given potential advisor will also want to ask you some questions, e.g. about your physics and math background, so they can scope out your suitability for working with them. The overall idea of these discussions is, of course, to allow you both to figure out if you are a good fit for each other.

Before taking on any graduate student (MSc or PhD), I chat with them during substantial face-to-face discussions, in line with department policy. I also require prospective grad students to have significant discussions with my colleagues as well, to get a sense for how our research group works. My colleagues in high-energy theory have similar principles too. We do not find it wise for anyone – either us or the prospective student – to start the PhD relationship without substantial discussions face-to-face: it is just too important to skimp on!

Please note: if you are stuck far away, e.g. in another country, and therefore unable to drop by for crucial face-to-face discussions, then computer technology can help. If this applies to you, please ask me directly via email about having (say) a Skype video session at a mutually agreed-upon time.

Background for UofT string

String theory as a subject can be technically challenging, and very beautiful. It involves a lot of theoretical physics and some mathematics. Useful subjects to study before starting string theory research are: quantum field theory, particle physics, general relativity, supersymmetric field theories, and geometry (especially differential geometry).

I recommend that all string theory graduate students own copies of the gold-standard textbooks String Theory by Joseph Polchinski (Cambridge, 2000) (both volumes), and Superstring Theory by Michael Green, John Schwarz and Edward Witten (Cambridge, 1988) (both volumes). A more introductory textbook, which is a beautifully constructed resource for beginners who want to learn the basics of string theory, is A First Course in String Theory, by Barton Zwiebach (Cambridge, 2009 second edition). There are also newer books which I am still in the process of reviewing and battle-testing, for example the Becker Becker Schwarz text and Michael Dine’s text.

One difficulty with picking string theory as a field to work in is that, like particle theory and a number of other highly abstract fields of physics, competition for academic jobs is fierce and there are also very few jobs outside of academia which directly use its research skills. For that reason, string theory groups are typically concentrated in research-intensive university physics departments offering doctoral degrees. In Canada, string theory groups are already established at UofT here in Toronto, at McGill in Montreal, at UBC in Vancouver, and at the Perimeter Institute in Waterloo.

Our group here benefits from an unusually strong Math department over the road, the Canadian Institute for Theoretical Astrophysics (CITA) upstairs, as well as the strong Astronomy department in the next building and the Fields Institute a hop skip and a jump away. Perimeter Insitute is also easy to visit for day trips.

Coming soon / here already?

If you have accepted an offer and are enrolled here, welcome!

Tip: to get a decent, and humorously brief, description of professors’ research be sure to attend the Jamboree in the week before classes start. The Beginning Of Term Party typically occurs straight afterwards.

Useful courses are plentiful on our Graduate menu, although it is worth noting that not all of the more specialized ones can be offered every year. In general, the best strategy is to use your opportunity to take interesting graduate courses to do two things: (a) to fill in any gaps in your general physics knowledge, and (b) to prepare for future PhD study in your specialized area of interest.

If you are sure that you want to do research in high-energy theory at UofT, e.g. in my group, the following is my recommended set of courses. Since students are expected to take 3 [half-]courses per semester in their first year, not four, I rank order them; you should pick three.

Fall:

1. PHY2403F Quantum Field Theory I
2. PHY1483F Relativity Theory
3. PHY2315F Advanced Statistical Mechanics or PHY1500F Statistical Mechanics
4. PHY1489F Introduction to High Energy Physics

Spring:

1. PHY2404S Quantum Field Theory II
2. PHY1484S General Relativity II or PHY2401S Cosmology and Black Holes
3. PHY2406/7S Special Topics in High-Energy Theory
4. PHY2321 Many-Body Theory

If right now you are not yet sure of your field of specialization, but want to keep your particle/string options open, then be sure to take PHY2403F, PHY2404S, and PHY1484S. These three courses contain fundamental core material on particle physics and quantum field theory (QFT), for both high-energy theorists and experimentalists, as well as for early universe cosmologists.

PHY1483F and PHY1484S on general relativity (GR) are, in turn, crucial for anyone working in a gravitational field (ha ha, yes, pun intended!). The links between early universe cosmology/astrophysics and high-energy physics are growing – both in theory and experiment. Therefore, it makes good scientific sense for all students planning to do research in string theory, early universe cosmology, and particle theory to take both QFT and GR.

Finally, the Special Topic course – which has alternated between Advanced Particle Theory PHY2407 and String Theory PHY2406, in adjacent years – completes the three semesters of courses that we recommend for all high-energy theory grad students.

Want to work in my group?

Generally, if you want to do a PhD in high-energy (particle/string) theory, in order to impress a potential PhD advisor at any university it helps to have good marks in your courses, especially in quantum field theory and relevant special topic courses. Independent initiative is also carefully noted – for example, attending seminars, asking questions outside classes and course curricula, etc.

If you plan to specialize in string theory research, the string theory course is the most relevant, and so it should be taken as soon as possible. If string theory is not offered in your first year, or you are looking for summer reading to get ahead pre-entry, you can study the excellent textbook by Barton Zwiebach: A First Course in String Theory, Cambridge, 2004 in the interim. Knowing the Zwiebach text helps put you in a strong position to start string theory research, because it gives basic intuition about stringy physics in a broader high-energy theory context.

Currently: I have two Ph.D. students and am likely to take on one more Ph.D. student in either 2011-12 or 2012-13.  In addition, I am always willing to give advice face-to-face to any student in high-energy theoretical physics looking for a graduate supervisor.

General advice

Graduate students in high-energy physics would be wise to plan on regularly attending our high-energy physics seminar series, to get to know our group members and to gain appreciation of the state of the art in research. If the level of seminars seems too high early on, you could take the initiative and start a pre-seminar meeting to discuss background material – try to find a senior grad student, postdoc or prof in the relevant sub-field to help explain jargon/technicalities. Mostly, we are delighted to respond to student initiative!

All graduate students, regardless of interest, would also be wise to make a habit of attending department colloquium on a regular basis. I strongly recommend that my own students attend colloquium every week, as matter of principle. The point of this is to develop well-roundedness as a physicist, and to open potential doors to multidisciplinary collaboration in future.

In addition, note that Teaching Assistantships are worthwhile because they help you learn how to teach, as well as earning you money. Getting TA experience during your PhD programme really helps prepare for the rough-and-tumble of scholarly debate in your area of eventual expertise.

Finally: the Associate Chair for Graduate Studies Prof. Stephen Julian and Graduate Administrative Staff are a truly excellent resource, and I suggest that you get acquainted with them early in your time as a graduate student. The Graduate Office is on the third floor of the McLennan Physics (MP) building’s Burton Tower, at the south-west corner. To get there, take the elevators to the 3rd floor, exit to the right, take another right turn, and keep going. Try not to bump into Krystyna Biel’s desk!

Enjoy.