Celebratio Mathematica

Thomas Milton Liggett

Remembering Tom Liggett

by Anna Ylvisaker and Don Ylvisaker

Tom Lig­gett entered our lives when he ar­rived at UCLA in 1969, the year after each of us had got­ten there. At the time he fell nat­ur­ally in­to a prob­ab­il­ity and stat­ist­ics group in the Math­em­at­ics De­part­ment that con­sisted of Paul Hoel and Tom Fer­guson, early mem­bers, to­geth­er with Sid Port, Chuck Stone and Bob Jen­nrich. It was an act­ive group — hold­ing a joint sem­in­ar, de­cid­ing on the teach­ing of rel­ev­ant classes and, im­port­antly, eat­ing an in­form­al lunch to­geth­er at the Stu­dent Uni­on.

He was a stu­dent of Sam Karlin’s at Stan­ford so we were fa­mil­i­ar with his back­ground, but he soon ex­ceeded any ex­pect­a­tions one might have had on such a basis. I don’t know that he had ever taught be­fore, but the or­gan­iz­a­tion and clar­ity he brought to his lec­tures was simply ex­traordin­ary, and at every level. His ad­min­is­trat­ive skills would prove more than evid­ent when he was called upon for such later in his ca­reer, and for the same reas­ons. His early re­search work was im­press­ively broad and deep, though one could hardly have fore­seen the im­mense in­flu­ence he has had on his area of in­terest, as at­tested to in this volume.

Our wives, Chris and Anna, co-work­ers in the Math­em­at­ics De­part­ment, are the best of friends, and this double con­nec­tion led to our con­sid­er­able in­volve­ment with the Lig­getts on a more per­son­al level. We wit­nessed the births of their chil­dren, the deaths of their par­ents, and had reg­u­lar get-to­geth­ers with their fam­il­ies on hol­i­days and oth­er oc­ca­sions. We miss those things.

Let me close with one an­ec­dote. Over din­ner at our house one night, it came out that we’d ac­quired an old cat burdened with fe­line aids and without teeth. His name was Thomas, of course, and Milton be­cause he was also nearly blind, hence Thomas Milton. Chris chimed in with “Do you know what Tom’s middle name is?”

We will miss Tom.

Anna Ylvi­saker was an ad­min­is­trat­or (1968–2004) in the De­part­ment of Math­em­at­ics at UCLA. Don Ylvi­saker is a pro­fess­or emer­it­us of stat­ist­ics there.