Celebratio Mathematica

I want to start with the day that Hirzebruch re­ceived the Wolf Prize. It was on May 12, 1988, in the Knes­set (the par­lia­ment) of Is­rael in Jer­u­s­alem — a very struc­tured ce­re­mony in the pres­ence of the pres­id­ent of the coun­try and five hun­dred guests. Hirzebruch was sixty years old at the time he was awar­ded the Wolf Prize. He was the young­est per­son and only the second Ger­man to have re­ceived it.

Two prizes in math­em­at­ics were awar­ded, and Hirzebruch was chosen to re­spond on be­half of him­self and the oth­er laur­eate. He came to the po­di­um to de­liv­er his speech. With his strong and dir­ect voice, he ex­pressed his grat­it­ude to the Wolf Found­a­tion for award­ing them the prize. He then ad­ded a few sen­tences on be­half of him­self only. When he com­pleted his speech, the audi­ence was dead si­lent for a few seconds, and then with tears in their eyes they star­ted to clap in a fash­ion that is usu­ally not seen in the aca­dem­ic world. They clapped and clapped more and more. He had spoken from his heart and had ex­posed his soul:

[…] As a pro­fess­or at the Uni­versity of Bonn, I am one of the suc­cessors of the fam­ous math­em­aticians Fe­lix Haus­dorff and Otto Toep­litz. Haus­dorff com­mit­ted sui­cide in 1942, to­geth­er with his wife, when de­port­a­tion to a con­cen­tra­tion camp was im­min­ent; Toep­litz emig­rated to Is­rael in 1939 and died there the fol­low­ing year. The memory of these math­em­aticians is with me al­ways on this trip.

In these three sen­tences he man­aged to cre­ate con­tinu­ity between the math­em­at­ic­al com­munity in Bonn be­fore and after the Nazis, to es­tab­lish links between the Jews in Ger­many and the Is­raeli so­ci­ety, and to pen­et­rate the hearts of the listen­ers.

Hirzebruch’s first vis­it to Is­rael was in 1981 by the in­vit­a­tion of Pi­at­et­ski-Sha­piro, my Ph.D. ad­visor at the time. He was widely wel­comed for be­ing the great math­em­atician he was, as well as for his lead­er­ship role in rees­tab­lish­ing math­em­at­ics in Europe after WWII. But it was only in the late 1980s that he star­ted to be act­ively in­volved in the math­em­at­ic­al re­search in­fra­struc­ture in Is­rael.

Hirzebruch had a fun­da­ment­al role in the Emmy No­eth­er In­sti­tute of Bar-Il­an Uni­versity. Fol­low­ing his ad­vice, we pre­pared an ap­plic­a­tion for a joint Ger­man-Is­raeli Min­erva cen­ter in math­em­at­ics. We named the cen­ter after one of the greatest sci­ent­ists of the twen­ti­eth cen­tury and one of the first fe­male math­em­aticians, the Ger­man-Jew­ish math­em­atician (who fled to the USA in the early 1930s) Emmy No­eth­er. The ap­plic­a­tion was sub­mit­ted to the Min­erva Found­a­tion (a sub­si­di­ary of the Max Planck So­ci­ety), and in 1991 it was ap­proved.

The in­aug­ur­a­tion ce­re­mony of the Emmy No­eth­er In­sti­tute took place in the house of the Is­raeli am­bas­sad­or in Bonn in Ju­ly 1992. A bin­a­tion­al Beir­at was ap­poin­ted by the Bar-Il­an Uni­versity and the BMBF. Hirzebruch was ap­poin­ted by the deputy min­is­ter of the BMBF as the chair­man of the Beir­at. He served as chair­man for twelve years, a role he took on with great com­mit­ment. He con­trib­uted his valu­able time (when ap­poin­ted he was still the dir­ect­or of MPIM in Bonn), his end­less en­ergy, his deep wis­dom, and his vast ex­per­i­ence to the suc­cess of the cen­ter. In 2000 he re­ceived an hon­or­ary de­gree from BIU for his con­tri­bu­tions.

Two ma­jor con­fer­ences in al­geb­ra­ic geo­metry were held in the cen­ter in his hon­or. “Hirz 65” was held in May 1993 and at­trac­ted an in­ter­na­tion­al audi­ence, in­clud­ing Fields medal­ists, dir­ect­ors of re­search in­sti­tutes world­wide, col­lab­or­at­ors, former stu­dents — all came to pay re­spect. “Hirz 80” was held in May 2008 and was one of the last big con­fer­ences he at­ten­ded. Again, five Fields medal­ists at­ten­ded, four Wolf Prize win­ners, and more. Fritz came, ac­com­pan­ied by his wife, Inge, and his son, Mi­chael. He was very pleased to meet old friends, at­ten­ded ALL the talks, and en­joyed the cel­eb­ra­tions and the tours to the Golan Heights and Jer­u­s­alem. Un­for­tu­nately, on the day be­fore the last, dur­ing a tour in the West­ern Wall caves, he fell and broke his leg, but then was most con­cerned that the con­fer­ence was con­tinu­ing as planned and kept apo­lo­giz­ing for dis­turb­ing the agenda!

I was re­flect­ing on the times (circa 1975) when, for me, the name Hirzebruch was the title of a yel­low book To­po­lo­gic­al Meth­ods in Al­geb­ra­ic Geo­metry, which, as part of my M.Sc. stud­ies, I had to read and then give a short­er proof of the Hirzebruch–Riemann–Roch The­or­em in the spe­cial case \( n = 3 \). In spring 1988 I par­ti­cip­ated in a spe­cial semester in Bonn on al­geb­ra­ic sur­faces, co­or­gan­ized by Hirzebruch. Ten years later, in sum­mer 1998, we or­gan­ized to­geth­er a spe­cial semester in the MPI, “To­po­logy of Al­geb­ra­ic Vari­et­ies”. He gave bril­liant lec­tures, present­ing com­plex geo­met­ric­al struc­tures in a simple and nat­ur­al way, demon­strat­ing beau­ti­ful ex­amples. I learned more about the skills that helped him rees­tab­lish the math­em­at­ic­al com­munity in Europe after the war. He nev­er for­got that math­em­at­ics is made of — and by — math­em­aticians. Listen­ing and at­tend­ing to every­body’s needs, “com­bin­ing” people, mak­ing his own friends in­to friends of one an­oth­er. A man who fol­lowed his val­ues with no ex­cep­tion. A noble man.