Denis Higgs

Denis Higgs

[Phil Scott]

Dear Category Theorists:

It is with great sadness that I wish to report the recent death of my
teacher Denis Higgs, known to many of the older generation of category
theorists.  Denis was an extremely creative and principled man, who was
a mathematician and political activist in South Africa during the early,
turbulent 1960s. He immigrated to Canada  (to Waterloo's Dept. of Pure
Mathematics) in the late 1960s.  Denis had wide mathematical interests
and published in many fields, including combinatorics, universal
algebra, category theory, and in later years algebraic integration and
abstract summability theory.  A list of his publications can be seen in
MathSciNet.

In category theory, he wrote an influential and beautiful long paper, "A
category approach to boolean valued set theory", which initiated many
early students in topos theory in the 1970s to Omega-valued sets.
(Unfortunately, only parts of this work were ever published.) With Keith
Rowe he worked on nuclear maps. His universal characterization of the
interval [0,\infty] led to his subsequent work on algebraic integration
theory, and is related to modern work on midpoint algebras. In later
years he developed a profound interest in abstract summability theory,
which began with his papers on Sigma Groups and their representation
theory in the 1980s and early '90s.

Alas, an automobile accident about 15 years ago left him in a very
difficult and painful state, which he endured with great courage. He
continued his researches when his health permitted, and he was working
on a monograph on abstract summability theory when his health recently
deteriorated. His students remember him as a brilliant and kind
scientist and mentor, who will be greatly missed.

  			Philip Scott
  			Dept. of Mathematics
  			U. Ottawa


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