Celebratio Mathematica

I met Shoshi­chi Kobay­ashi when we both ar­rived at Berke­ley in Septem­ber of 1962. We got to know each oth­er quite well for two reas­ons. First, the dif­fer­en­tial geo­metry group at Berke­ley, just then form­ing un­der Pro­fess­or Chern’s guid­ance, was very co­hes­ive, both so­cially and math­em­at­ic­ally. Second, we shared an of­fice where we had many in­form­al con­ver­sa­tions about dif­fer­en­tial geo­metry, math­em­at­ics in gen­er­al, and aca­dem­ic life. I al­ways learned some in­ter­est­ing math­em­at­ics when Sho and I talked. Years be­fore, I had read Nom­izu’s short pa­per­back Lie Groups and Dif­fer­en­tial Geo­metry, and I was thrilled to learn that Shoshi­chi had just com­pleted his mo­nu­ment­al work on dif­fer­en­tial geo­metry with Nom­izu. At vari­ous times dur­ing the 1960s the geo­metry group at Berke­ley in­cluded S.-S. Chern, Sho Kobay­ashi, Phil Grif­fiths, Jim Si­mons, Al­fred Gray, Peter Gilkey, Jeff Chee­ger, Blaine Lawson, No­lan Wal­lach, Man­fredo do Car­mo, Wu-Yi Hsiang, Hung-Hsi Wu, me, and many oth­ers. It was very col­lab­or­at­ive and did not draw dis­tinc­tions between big shots, young aca­dem­ics, and gradu­ate stu­dents. And there were many fam­ous and in­flu­en­tial vis­it­ors at­trac­ted by Chern, in­clud­ing Gene Calabi and Fritz Hirzebruch. So it was a kind of math­em­at­ic­al heav­en. Dur­ing this time Shoshi­chi con­struc­ted his pseudo-met­ric, with the as­so­ci­ated no­tion of Kobay­ashi hy­per­bol­i­city, and also his re­pro­du­cing ker­nel meth­ods for ir­re­du­cib­il­ity of unit­ary rep­res­ent­a­tions.

When the build­ing that cur­rently houses the math de­part­ment (Evans Hall) was built, math was to have floors sev­en, eight, nine, and ten. Sho and I went in­to the build­ing to choose our of­fices be­fore the el­ev­at­ors were in­stalled. We walked up the stairs to­geth­er, and at some point I real­ized that he was speed­ing up. I couldn’t keep pace, but he had to stop at the sev­enth floor and I man­aged to get to the eighth. So his new of­fice was on the sev­enth floor and mine was on the eighth. Later, when Sho was math de­part­ment chair, the chan­cel­lor’s of­fice in­formed him that we were los­ing our space on the sev­enth floor. With Sho in charge we came out of these “space wars” pretty well, re­tain­ing most of the sev­enth floor.

It is hard to real­ize that Sho is no longer with us. It was a great priv­ilege to have been a friend and col­league of Shoshi­chi Kobay­ashi.