Elhunyt Seress Ákos

Fájdalommal tudatjuk, hogy intézetünk egykori munkatársa, Seress Ákos, az Ohio State University professzora életének 55. évében 2013. február 13-án Columbusban (Ohio, USA) elhunyt. Ákos az ELTE matematikus szakának elvégzése után egy évig volt az intézet munkatársa, majd doktori tanulmányok céljából az OSU-ra ment, ahol aztán állást is kapott. A késôbbiekben is gyakran töltött hosszabb-rövidebb idôszakokat a Rényi Intézetben.

A Diszkrét Matematika és az Algebra Osztály közös szemináriumán a közeljövôben megemlékezünk róla és eredményeirôl.

Az alább olvasható nekrológot Babai László és Eamonn O'Brien (a számítógépes csoportelmélet vezetô kutatója) írták Ákosról.

We have learned with great sadness that Akos Seress passed away Wednesday evening, February 13, in Columbus, Ohio.

Akos was an outstanding mathematician, author of a book on algorithmic group theory and over a hundred papers on asymptotic and algorithmic group theory and combinatorics. He was an invited speaker at the 2006 International Congress of Mathematicians in Madrid. In addition to his theoretical work, he was a major contributor to the GAP computational algebra system. He was an indefatigable architect of bridges between the computational group theory and the theory of computing communities.

Born in Budapest on November 24, 1958, Akos studied mathematics at Eotvos University, Budapest where he began publishing in combinatorics while an undergraduate. He completed his Ph.D. at the Ohio State University under Dijen Ray-Chaudhury. Subsequently he entered the field of algorithmic group theory in a series of joint papers with Babai and Luks on the complexity of permutation group algorithms and wrote the definitive monograph on the subject. He continued with a series of important papers on the statistical theory of finite simple groups with Bill Kantor and others; this line of work contributed to a recent definitive result on the complexity of algorithms for matrix groups over finite fields by Akos and coauthors. He has also extensively contributed to the asymptotic theory of permutation groups, vertex-transitive graphs, extremal combinatorics, and the theory of designs.

Motivated by the theoretical results on algorithms for permutation groups, Akos pioneered the implementation of these algorithms in the GAP computational algebra system. Developed in the 1990s, with the cooperation and support of the Aachen group, Akos's packages delivered, for the first time, practical performance backed up by theoretical analysis. His modular design and black-box techniques allow an easy adaptation to other representations; his work is widely used today as infrastructure both for permutation groups and for matrix groups. More recently Akos and Max Neunhoeffer have developed efficient implementations of a suite of algorithms for matrix groups.

Akos has been a tireless builder of communities, his own work and example demonstrating the bridge between the "red-hats," those who create "paper-algorithms" with proven asymptotic performance guarantees, and the "green-hats," the computational group theorists who demand working code to study the stucture of concrete groups. Akos, along with Bill Kantor, has been a chief organizer of a series of meetings that brought these two communities together.

Akos spent most of his professional career at the Ohio State University, with extended visits to the University of Western Australia. He died at the age of 54 of renal cell carcinoma, a particularly aggressive form of cancer, diagnosed only six months ago. The disease struck him at the height of his creative powers. His paper "Construction of 2-Closed M-Representations" received the Distinguished paper award at ISSAC 2012 (Intl. Symp. on Symbolic and Algebraic Manipulation) and was hailed as "a groundbreaking work" that "marks a turning point in Majorana Theory." His most recent work, with Harald Helfgott, under publication in the Annals of Mathematics, gives a long-sought bound on the diameter of the alternating and symmetric groups and represents a tour de force in the study of the geometry of finite simple groups.

Akos has been a most generous friend, colleague, and mentor. His passing will be felt deeply by all around the globe whose lives he touched and whose careers he enriched. Our hearts go out to his wife Sherry and his son Laszlo.

-- Laszlo Babai and Eamonn O'Brien