to TW's top page (English)
[to TW's top page (Japanese)]
[IPMU science top]
What is it like to be a Ph.D. student at Kavli IPMU, in particle theory, with TW as an adviser?
(Kavli Institute for the Physics and Mathematics of the Universe)
is a research institute that belongs to the University of Tokyo. Its
research spectrum ranges from astronomy to arithmetic geometry.
For more about the science we do, see the page of
Kavli IPMU participates in the Ph.D. program of the University of Tokyo, by
having some of its faculty members appointed at the Physics Major Course
of the Graduate School of Science, at the Graduate School of
Mathematical Science, and at the Astronomy Major Course of the
Graduate School of Science.
The admission channels I am committed to
The Graduate School of Science at the University of Tokyo adopts a two-stage
system in all of the addmission options for international students.
Before the official selection by the Graduate School of Science, the applicants need to clear the pre-selection process run by individual faculty members
appointed at the Graduate School of Science. In 20xx autumn, for students
enrolling in September 20xx+1, I myself(Watari) and some other faculty members
of the Physics Major Course run this pre-selection process jointly.
If you are interested in choosing me as a prospective adviser, then you are
invited to proceed to the page of
the joint pre-selection process and follow
the instruction there.
As a policy of my own, I am open to the admission
options for international students starting their Ph.D. course
in September (not for students starting in April).
There are still a few admission options that the University of Tokyo offers.
Among them, I open my window only through the GSGC course and the regular
course (but not through the Government scholarships).
I must ask for your understanding.
Also as a policy of my own, I welcome
international students to the Ph.D. program only from the Master course,
not directly into the Doctor course; this policy is also applied to
domestic students. I know that some of the applicants have been
finishing a Master course elsewhere at the time applying for the
graduate study at U. Tokyo, but still I maintain this policy; see
additional remark in the "Master Thesis and..." section below.
For Students Applying for the Enrollment in September, 2022
I myself can take at most three Ph.D. students without degrading the
quality of service as an adviser, besides the sduents in the
first semester (who are occupied with taking course and reading textbooks).
As one of my students is graduating in the spring of 2023, I can host
one student enrolling in the autumn of 2022, and serve as the thesis
In addition, at Kavli IPMU, there are two young faculty
members---Prof. Tom Melia and Prof. Satoshi Shirai---in the field of
particle theory. Both do not
have a graduate school appointment at this moment, which means
that they cannot be a supervisor officially, but conduct research
independently from other faculty members, and are committed to
our Ph.D. program. So, I am happy to host some students as
the official supervisor, and make it possible for those students
to be supervised by Tom or Satoshi in practice. If a student wishes
to seek for such an arrangement, then he/she might think of including me (**)
in the list of preferred advisor when applying to the preselection,
and referring to such an arrangment (with the name of Profs.
Melia and/or Shirai) in the Statement of Purpose for the preselection.
(**) Some other particle-theory faculty members at Kavli IPMU are also
happy to provide such an arrangement with Profs. Melia and Shirai.
In this year,
- Prof. Melia: already committed to two students.
not impossible to serve as the adviser in practice for one more student
starting in the autumn of 2022, but the threshold is set a little higher.
- Prof. Shirai: not considering to start serving as the primary adviser
in practice for students starting in the autumn of 2022. does not rule out an
opportunity to work on research projects together with those students, though.
Master Thesis and Qualification for the Doctor Course
There are a lot of things to learn in theoretical particle physics.
So, in theoretical particle physics at the Physics Major Course, we do
not necessarily require a graduate student to have produced an original
scientific result for a master thesis. It suffices to write up a review
article on a topic in this field to prepare himself/herself ready to be
engaged in reserach projects soon after the master thesis defense.
We require (at least I definitely do), though, that a student has
acquired basic ethics and skills of scientists, including honesty about
what she/he is not sure about---(*), skills of critical thinking, logical
thinking, and of exchanging ideas clearly (not just absorbing knowledge),
by the end of the Master Course.
If we are not sure whether a graduate student has been achieving that,
we might recommend the student to leave academia without proceeding to the
(*) has been the first principle of academia, in Western as well as Asian
World, not just in humanity but also in natural science.
(Confucius) To take the things you know as what you know, and things you are not sure about as what you do not know yet, --- this is to know things. 知之為知之, 不知為不知. 是知也.
(R. Feynman, a commencement address) The first principle is that you must not fool
yourself, --- and you are the easiest person to fool.
As I wrote earlier (above), I ask all the students to go through this
master thesis defense, even when one has finished a master course
elsewhere before coming to the University of Tokyo graduate school.
If such a student shows good enough performance, then we have an option
to shorten the whole Ph.D. program (master course + doctor course) by 1 year.
We will authorize shortning the master course when the criterion above is met.
It is not always the best option to do so for graduate students, though,
because most of scholarship options in Japan for the doctor course (the
latter half of the Ph.D. program) do not cover extension beyond three years
in the doctor course; graduate students need to be "ready" when entering
the doctor course. An option of shortning the doctor course is approved
by the Physics Major Course for truly outstanding students (on average,
one student in five years or so?).
What Kind of Topics Do I Work On?
See this page
for my reserach interests.
How to Get into the Stage of Research, when I Serve as Your Adviser
My students are usually invited to join one of research porjects I have
in their 2nd half of the 1st year of the Ph.D. program; they are often
occupied with taking courses in the 1st half of the 1st year.
It is often very difficult at that stage to be the leading player in
a collaboration on research topics in string theory, but that is fine.
As students grow up and gain power, I gradually change my role from
leading a collaboration to supporting students leading a collaboration.
When a student shows an outstanding growth curve, I will recommend
him/her to try to complete a project by onselef, or to have an
opportunity to work with other experienced scientisits.
The research projects that I invite a 1st-year student to is likely to be
one of the topics at the beginning of the page
If You Wish to Work in an Area of String Theory Close to Mathematics...
I use math heavily in my research projects.
That will be clear from the information in the page
(my research interests).
I recommend (and also assume) that students working with me on
research projects have read at least one math textbook, preferrablly
a bit more, before coming to the graduste school of U. Tokyo.
Math is not the same as physics, especially in that we are allowed to
conclude in physics that something is "roughly OK" based in intuitions,
or "presumably correct when all things considered," whereas not much value is
given to such observations in mathematics. With the physics approach, we
can get things done faster, but too much indulgence in the culture
of "presumably roughly OK" might take us away from tough and solid
logical reasonings. An experience of reading a math textbook line by line,
by filling the logic between the lines, is a good way to maintain loose
contact with the math-department culture requiring solid logical foundation.