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## Josef Paldus (1935-2023)

Distinguished Professor Emeritus Josef Paldus passed away peacefully on Sunday January 15, 2023.

Prof. Paldus obtained his M.Sc. Degree in 1958 from the Faculty of Mathematics and Physics of the Charles University in Prague, Czechia, and his Ph.D. (CSc.) in 1961 from the Institute for Physical Chemistry of the Czechoslovak Academy of Sciences, the same year he married his lifetime partner, Eva. From 1962 to 1964, he pursued his postdoctoral studies at the Division of Pure Physics of the National Research Council of Canada in Ottawa under the guidance of Dr. Don Ramsey and Dr. Gerhard Herzberg.

In 1968, after emigrating to Canada, he became an Associate Professor in the Department of Applied Mathematics at the fledgling University of Waterloo in Waterloo, Ontario, Canada. Seven years later, he was promoted to Full Professor in both the Applied Mathematics and Chemistry Departments, and continued help build a world class department. In 1984, he joined the Quantum Theory Project and also served as an Adjunct Professor in the Department of Chemistry at the University of Florida, Gainesville. He was also the Associate Director of The Fields Institute for Research in Mathematical Sciences in Toronto, Ontario, Canada, from 1991 to 1994. Until his death, he continued to serve as a Distinguished Professor Emeritus in the Quantum Theory Group, in the Department of Applied Mathematics at the University of Waterloo.

Prof. Paldus leaves behind a great body of work on coupled cluster theory, where he and Jiří Čížek adapted the many-body coupled cluster method to many-electron systems, thus making it a viable method in the study of the electronic correlation that occurs in atoms and molecules. He was also well-known for his contributions to the Unitary Group Approach. This approach regards the computation of Hamiltonian matrix elements over N-electron spin eigenstates that appear in electronic correlation problems.

During his remarkable career spanning over 6 decades, he served as a Visiting Professor at several universities and research institutions in such countries as France, Germany, Italy, The Netherlands, and Israel, as well as organizing many international conferences and summer schools. Amongst many international prizes and honors, he received honorary degrees from Charles University Prague, Bratislava, and Strasbourg, as well as becoming a Fellow of the Royal Society of Canada and the American Institute of Physics. He also served as a member of numerous editorial and advisory boards of scientific journals in chemical physics, including the *International Journal of Quantum Chemistry, Advances in Quantum Chemistry, Journal of Chemical Physics, Therotica Chimica Acta, Journal of Mathematical Chemistry, and the Canadian Journal of Chemistry*.

A number of you will have known "Joe" as teacher, colleague, friend. He will be greatly missed and the world will not be the same without him.

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## Peter Ponzo (1934-2020)

We are sad to share the news that Peter Ponzo passed away peacefully on July 5, 2020 after a battle with bone cancer.

When Mathematics became a Faculty in 1968, Peter was named chair of the Department of Applied Mathematics. He later became the Associate Dean of the Faculty of Mathematics. He retired after 30 years of teaching with the distinction of Professor Emeritus.

“Peter wrote one of the first papers on a mathematical model of tumour growth…before the whole field became fashionable(!),” recalled Siv Sivaloganathan, chair of the department. “He will be greatly missed by those that knew him.”

Peter authored a book to celebrate the first 25 years of computer science at the University of Waterloo. Distinguished Professor Emeritus Don Cowan, the founding chair of the computer science department, now known as the David R. Cheriton School of Computer Science and Wes Graham asked Peter to write the book.

“Peter was incredibly talented. He was a writer, artist, gifted educator, researcher and wonderful collaborator,” remembered Cowan. “As an educator, he had the ability to communicate ideas to students at all educational levels. As a collaborator, he always worked for the common good of all involved. Peter had a wonderful sense of humour, which he expressed in both the written word and his cartoons. Peter will be missed very much by all who knew and worked with him.”

Peter also authored a book about the origins of math contests in 1995. Today, the Centre for Education in Mathematics and Computing (CEMC) runs the contests and holds outreach programs through the year, but back then Peter was heavily involved in running the contests and taught calculus to high school students attending the Summer Seminars at Dunkley’s request.

Following his retirement, Peter wrote novels, educational pieces about calculus and losing money in the stock market, and a blog, in addition to camping, cruising and spending time with his children and grandchildren. The Globe & Mail published a piece about Peter’s tests of investing formulas and strategies as he managed his own retirement savings. He took his learning and created a large number of tutorials known as gummy-stuff.

In lieu of flowers, donations in his memory can be made to the Peter Ponzo Memorial Fund.

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## Giuseppe (Pino) Tenti (1940-2016)

It is with great sadness that we annouse that Dr. Giuseppe (Pino) Tenti, Professor Emeritus in the Department of Applied Mathematics, passed away on Friday, June 10th following a short battle with gastric cancer.

Although, he had been at Waterloo from 1974-1980 as postdoctoral fellow/research associate and research assistant professor, Pino returned from the USA to join the Department as a permanent faculty member in 1983. From 1983 until his retirement in 2006, he was an active participant in many aspects of university life but was particularly known for the energy and dedication he put into undergraduate teaching. Although retired for the past ten years, he was nevertheless very active in research, working closely with graduate students in the Mathematical Medicine Research Group, right up until his illness. He had been happily married to his wife Pina for 46 years, and retirement afforded him the opportunity to enjoy more rounds of golf with her, and also to indulge in another of his passions, cooking.

For the many of us that knew him, it was plain to see that Pino put his heart and soul into trying to impart his love of learning and his clear, logical thinking to others - his impact on countless generations of students is, no doubt, profound and far reaching. His former students went on to graduate school at leading institutions including Princeton, MIT, Cornell, and several of them are now professors at Waterloo, and at other universities in Canada and around the world.

To honour his legacy of inspirational teaching and his motivation of many to pursue a research career in applied mathematics, the department and the family of Dr. Tenti will be setting up a scholarship in his memory.