午夜剧场

My specialty is "cooperative games." In cooperative games, we consider the problem of how to distribute the benefits gained when multiple players cooperate. The so-called "axiomatic analysis of cooperative games" involves formulating desirable properties that a distribution rule should satisfy as "axioms" and examining the logical relationships and compatibility of various axioms.

In this respect, my research is very close in both content and methodology to the field of "social choice theory," which is famous for "Arrow's theorem." This theorem proves that the logical consequence of several democratic requirements for social decision-making rules is the existence of a dictator.

Game theory is generally considered to consist of "non-cooperative games" and "cooperative games," but typically, "game theory" refers to non-cooperative games. Cooperative games are a very minor field with few experts, but it is a very rewarding area with many important unsolved problems remaining.

For the past few years, I feel I was only writing superficial papers and just pretending to do research. However, since moving to this university, my passion for research, which I had almost forgotten, has been rekindled, and I have started to tackle some of the problems that I had left untouched for many years. I think I've been stimulated by occasionally participating in the mathematical economics seminar on Mondays and by teaching a cooperative games class in a graduate school seminar. Since I am in such a good environment, I want to move away from research that just patches things together with superficial techniques and instead take my time to tackle important unsolved problems that might take several years to find an answer for.

Outside of research, I often read books on physics, sparked by a book I happened to find in a bookstore on a business trip a few years ago: Roger Penrose's "The Road to Reality." When you specialize in game theory or microeconomics and use mathematics to write papers or give lectures, it's easy to mistakenly think you know a lot about mathematics. But in these physics books, I encounter mathematics I've never even heard of, like "covariant derivatives" and "Lie derivatives." When I don't understand something, I look for a good textbook and read it, which I quite enjoy.

Graduate-level microeconomics sometimes uses "differential topology," so I had studied the basics. When I read in a book that "Einstein's general theory of relativity uses differential topology," I thought I might have the groundwork to understand it. I tried reading Einstein's papers and textbooks on gravitational theory, only to find that the level of mathematics used was completely different from what I knew, so I'm studying it all over again from scratch. Recently, I've become more accustomed to so-called "tensor calculus," and I can now somehow understand the beginning of Dirac's "General Theory of Relativity."

Currently, my only undergraduate class is a seminar, but starting in the fall, I will be teaching microeconomics at Hiyoshi. Intermediate and advanced game theory and microeconomics often use mathematics, which discourages many people from studying them. However, I believe the important thing is to understand that "although it involves complicated-looking mathematics, this is what's essentially being done." I'm relatively good at this kind of explanation, so if you ask me in a seminar or another class to "explain this part in a simple way because it seems mathematically difficult but interesting," I think I can be of help.

(Interview conducted on May 28, 2009)