Andrew Ranicki has died. Ranicki was a topologist, with particular expertise in algebraic surgery. Indeed, Ranicki had the unusual title of Professor of Algebraic Surgery at the University of Edinburgh. (Andrew was a special case for almost everything.) His two papers on surgery in Proc. London Math. Soc. [MR0560997 and MR0566491 (*****)] were among his most cited papers. He was also familiar to many for his work in $K$-theory, including his work as an editor for leading journals in the subject.

Ranicki received his doctorate from Cambridge University under the supervision of Adams and Casson with a dissertation titled “Algebraic L-Theory”. After Cambridge, he had positions at IHES, Princeton University, and the Institute for Advanced Studies. He came to Edinburgh in 1982. He had eleven PhD students. In MathSciNet, he has 23 coauthors.

The sharing of mathematics was important to Ranicki. Many years ago, he told me about a project for videos of lectures on topology. Ranicki and others were gathering existing videos, plus recording new videos to cover essential topics. They needed a convenient way to catalogue the URLs for the videos. Ranicki and his collaborators turned to Pinterest (which must have been just out of beta), creating the board Surgery Theory in Topology. I had never heard of Pinterest, so this was my only exposure to it and figured it was some variant on math.stackexchange. I was surprised when my sister-in-law told me that she was active on Pinterest for information on recipes. She was more appropriately surprised to learn that I had an account and that I thought it was for mathematics and science. But, it worked for Ranicki — at least for a while. His account went dormant after a few years.

Ranicki also shared what he knew through his writing, having written a half dozen books. A list of them is at the end of this post. He also edited or contributed to fifteen other books, collections, and conference proceedings.

Ranicki was a remarkable mathematician, but perhaps an even more remarkable person. Many people would comment on his infectious laugh. And he laughed often. On my various visits to the University of Edinburgh to work with Toby Bailey, Andrew would go out of his way to make me feel welcome. His home with his wife Ida Thompson was the site of many a gathering of mathematicians in Edinburgh.

Andrew’s father was Marcel Reich-Ranicki, a very well-known literary critic and essayist, who, among many other things, was a writer and editor for the *Frankfurter Allgemeine Zeitung*. Both of Andrew’s parents were survivors of the Holocaust. Their personal history was hugely important to Andrew. Through them, he knew directly of incredible horrors. Yet, Andrew was an incredibly positive person who loved life and loved people.

### Books by Andrew Ranicki:

MR0620795

Ranicki, Andrew

Exact sequences in the algebraic theory of surgery.

Mathematical Notes, 26. Princeton University Press, Princeton, N.J.; University of Tokyo Press, Tokyo, 1981. xvii+864 pp. ISBN: 0-691-08276-6

MR1208729

Ranicki, Andrew(4-EDIN)

Lower K- and L-theory.

London Mathematical Society Lecture Note Series, 178. Cambridge University Press, Cambridge, 1992. vi+174 pp. ISBN: 0-521-43801-2

MR1211640

Ranicki, A. A.(4-EDIN)

Algebraic L-theory and topological manifolds.

Cambridge Tracts in Mathematics, 102. Cambridge University Press, Cambridge, 1992. viii+358 pp. ISBN: 0-521-42024-5

MR1410261

Hughes, Bruce(1-VDB); Ranicki, Andrew(4-EDIN)

Ends of complexes.

Cambridge Tracts in Mathematics, 123. Cambridge University Press, Cambridge, 1996. xxvi+353 pp. ISBN: 0-521-57625-3

MR1713074

Ranicki, Andrew(4-EDIN-MS)

High-dimensional knot theory.

Algebraic surgery in codimension 2. With an appendix by Elmar Winkelnkemper. Springer Monographs in Mathematics. Springer-Verlag, New York, 1998. xxxvi+646 pp. ISBN: 3-540-63389-8

MR2061749

Ranicki, Andrew(4-EDIN-MS)

Algebraic and geometric surgery.

Oxford Mathematical Monographs. Oxford Science Publications. The Clarendon Press, Oxford University Press, Oxford, 2002. xii+373 pp. ISBN: 0-19-850924-3

He was also an author on

MR1434100

Ranicki, A. A.(4-EDIN-MS); Casson, A. J.(1-CA); Sullivan, D. P.(1-CUNY); Armstrong, M. A.(4-DRHM); Rourke, C. P.(4-WARW-MI); Cooke, G. E.

The Hauptvermutung book.

A collection of papers of the topology of manifolds. K-Monographs in Mathematics, 1. Kluwer Academic Publishers, Dordrecht, 1996. vi+190 pp. ISBN: 0-7923-4174-0

(*****) For the joint review of the two Proc. London Math. Soc. papers, I recommend the PDF version, as the commutative diagram in the review does not render in MathJax.