Celebratio Mathematica

Thomas Milton Liggett

My interactions with Tom

by Jeff Steif

My first con­tact with Tom was not with him but, like many, with his first book. I was in my third year as a Ph.D. stu­dent at Stan­ford in 1985, plan­ning to work with Don­ald Orn­stein but I told him that I was most in­ter­ested in prob­ab­il­ity the­ory. Orn­stein sug­ges­ted to me to look at this book “that had just come out on in­ter­act­ing particle sys­tems”1 and to try to look at these sys­tems from an er­god­ic the­or­et­ic point of view. That was my thes­is. If it were not for Tom’s book, my thes­is would have been quite dif­fer­ent.

I then met Tom for the first time in 1988, just when I was gradu­at­ing, at a con­fer­ence at Cor­nell that Rick Dur­rett was or­gan­iz­ing. He was very friendly to me, ask­ing me what I had been work­ing on, and it was a pleas­ure to talk with him.

After that, for many years, I reg­u­larly sent Tom many var­ied ques­tions on in­ter­act­ing particle sys­tems. Prob­ably too many. He was al­ways will­ing to re­spond to all of them and was al­ways very help­ful.

In 2004, Tom par­ti­cip­ated in a con­fer­ence in Gothen­burg at which point our dis­cus­sions led to two pa­pers, one to­geth­er with Bálint Tóth.2

It was through these in­ter­ac­tions that I ex­per­i­enced firsthand Tom’s power­ful ana­lyt­ic abil­it­ies. It was a great ex­per­i­ence for me to work with him.

I had the pleas­ure in 2009 to par­ti­cip­ate in a con­fer­ence in Tom’s hon­or in Beijing where we cel­eb­rated him and his achieve­ments, and where I was able to meet his wife Chris.

Tom’s in­flu­ence on prob­ab­il­ity and in par­tic­u­lar in­ter­act­ing particle sys­tems is ob­vi­ous. I my­self feel priv­ileged to have had an op­por­tun­ity to work with him.

Jeff Steif is a pro­fess­or on the Math­em­at­ic­al Sci­ences fac­ulty at Chalmers Uni­versity of Tech­no­logy in Göte­g­urg, Sweden.