[No. 163] Takamichi Sano

Ever since I was little, I was good at and liked arithmetic. In junior high and high school, my best subject was math; conversely, I was hopeless at subjects other than math (though I was good at physics). Until my second year of high school, I just liked math as my best subject. But in my third year, I got hooked on reading the Blue Backs series (Kodansha), and I discovered the fun of mathematics by reading "Solving Algebra with Geometry" by Yoshisaku Nakamura and Keiichi Abe, and "Modern Mathematics as Seen in Math Olympiad Problems" by Hiroyuki Kojima. I also read books like Masahiko Fujiwara's "The Glory and Failure of Geniuses" and the famous "Fermat's Last Theorem" by Simon Singh, and I gradually began to think that I wanted to become a mathematician in the future. I just happened to see these books for sale for 105 yen at Book Off, thought they looked interesting, and bought them to read, but you never know what will be a turning point in your life.

After entering university, I was surprised by the style of math classes, which was different from what I had experienced up to high school. The classes that left a particularly strong impression on me were Professor Iguchi's analysis and Professor Bannai's topology in my second year, Professor Shimomura's complex analysis, and in my third year, Professor Sakagawa's probability theory and Professor Kurihara's ring theory. Professor Iguchi's lectures were precise and highly polished, and I felt that the report problems assigned each time were cleverly designed with a moderate level of difficulty. In Professor Bannai's class, I was particularly moved by how the definition of continuity using the ε-δ argument was brilliantly rephrased in the language of topology. Professor Shimomura's class was the first period on Saturdays, and his style was shocking: he would show up empty-handed every time and write smoothly on the blackboard without looking at any notes. I remember that Professor Sakagawa's lectures had concise and brilliant arguments, and they always left me feeling refreshed. Professor Kurihara would later become my mentor. His classes revealed his own taste in mathematics, as he would, for example, prove Fermat's theorem that "a prime number that leaves a remainder of 1 when divided by 4 can be expressed as the sum of two squares" using ring theory, or share the anecdote that the proof of Hilbert's basis theorem was initially criticized as "This is not mathematics, it is theology."

Starting in the fall semester of my second year, I hit it off with my classmate Okawa, and we decided to hold an independent study seminar together. We decided it would be best to have a professor oversee it, so we went to ask Professor Tanaka, who was in charge of the group theory tutorials. At Professor Tanaka's recommendation, we ended up reading Silverman and Tate's "Rational Points on Elliptic Curves" together. We held this independent seminar once a week, and it continued for about a year and a half until the end of my third year. In my fourth year, I joined Professor Kurihara's seminar, but since I had already been trained in our independent seminar, Professor Kurihara commented, "You're already used to this," after my first presentation.

In this way, I was able to spend my time doing the mathematics I loved, blessed with good friends and teachers, and had an enjoyable time as an undergraduate. The only somber memory from the end of that period was the cancellation of our graduation ceremony due to the Great East Japan Earthquake.

After that, I went on to graduate school, and after a training period filled with both laughter and tears, I officially became a mathematician.

Not everything has been smooth sailing since becoming a mathematician, but my desire to continue pursuing the mathematics I love has only grown stronger.