January 9, 2024

In September 2023 the journal Transformation Groups published a special volume dedicated to the memory of Professor Jim Humphreys, our late colleague. Jim, who joined the faculty in 1974 and became emeritus in 2003, passed away in August 2020. Jim was a prolific author and an influential researcher. His research focused on algebraic questions related to simple Lie algebras, whose classification boils down to understanding the most common symmetry groups, including the symmetries of the cube and the tetrahedron and their generalizations to higher dimensions. Jim had a deep influence on this subject due to his textbooks, several of which became standard references.

The special volume included articles by leading researchers in the representation theory of algebraic groups and Lie algebras. Several members of the department played a role in the volume. It was co-edited by Professor Eric Sommers, and both Professor Emeritus Ivan Mirkovic and Professor Alexei Oblomkov contributed articles.

Beyond his research Jim played a role in supporting many different communities across mathematics. For instance, in 1980 soon after diplomatic relations opened between the US and China, he visited and lectured at East China Normal University, at the invitation of Professor Cao Xi Hua. Below is a picture from that visit:

A group picture of the students at East China Normal University.


In an email to his former PhD student Zhongzhu Lin, Jim recollected

"I recall vividly my thoughts when I went to the departmental mailroom on February 15, 1979 and found a small airmail letter from Shanghai containing a message typed in Chinese along with an English translation, signed by Cao Xi Hua. It was just two weeks after the resumption of diplomatic relations between the US and the PRC, negotiated at the Jing Jiang Hotel in Shanghai by Nixon and Zhou. The letter invited me to visit ECNU and give some lectures there, though of course I had no idea then who Professor Cao was. I soon discovered that he was a student of Richard Brauer at U. Michigan, who had returned to China soon after the revolution. When I went to Shanghai in the spring of 1980, I met Cao and learned how influential he had been in that university, as well as how friendly he was and how helpful in my stay at a modern annex of the Jing Jiang Hotel (the university having no guesthouse at the time)."

This visit was one of the first steps in the broader opening of academic interaction between China and the US.

Another example of Jim's influence is recounted in a Notices article about the origins of the organization Spectra. In 1992 Colorado passed an amendment that not only overturned local laws banning discrimination on the basis of sexual orientation but forbade such laws; in other words, such discrimination was legal in Colorado. Jim then wrote a letter to the leadership of the AMS advocating that Denver should not host Joint Math Meeting in 1995, despite all the planning that had already happened. This letter, and a letter by David Pengelley, initiated a substantive discussion, and the JMM was subsequently moved to San Francisco. Moreover, Jim was on the steering committee for an LGBT reception at that JMM, and this event, which became annual, catalyzed the formation of a network of people that transformed the mathematical community. For the article, see https://www.ams.org/journals/notices/201906/rnoti-p875.pdf.

The opening picture is of Jim with some former PhD students and with George Lusztig of MIT and the late Professor Mei-chin Ku of UMass. Here is a bigger copy:

A group picture of Humphreys' graduate students.