Dorin Ghisa, a mathematics professor at Glendon College for more than 20 years, died at the age of 85.
Ghisa earned his BSc, MSc and PhD in mathematics in Romania throughout the 1960s and 1970s before coming to Canada. He taught at Université de Montréal, École Polytechnique de Montréal and Université de Moncton before joining 91ÑÇÉ« in 1985 as a special associate professor of mathematics at Glendon College.
Over more than two decades at Glendon, Ghisa he led courses in complex and real analysis, operations research, statistics and calculus, in both English and French. Teaching was a deep commitment for Ghisa – one so strong that a colleague recalls how, once after undergoing major spine surgery on a Friday, he returned to the classroom the following Monday.
Beyond the classroom, Ghisa contributed extensively to academic life at 91ÑÇÉ«. He served as a course director and as a member of the curriculum committee on the Glendon College Faculty Council. He also spent three years on 91ÑÇÉ« Senate with the Senate Committee on Admissions, Recruitment and Student Assistance, and helped Frost Library strengthen its mathematics collection.
In his scholarly contributions, Ghisa was interested in complex analysis and measure theory throughout his career, fields concerned with the behaviour and structure of mathematical functions. Dating back to his PhD thesis defence in 1976, he was especially interested in the work of Bernhard Riemann, a 19th‑century German mathematician, and in the Riemann Hypothesis, a famous unresolved problem linking a central mathematical function to the distribution of prime numbers.
This interest led Ghisa to publish a book in 2012 titled Fundamental Domains and the Riemann Hypothesis, which examined recent advances in the study of mathematical functions and explored how these ideas might help clarify the Riemann Hypothesis and related questions in complex analysis. The book added to a substantial body of scholarly work, including more than 30 published articles spanning both pure and applied mathematics, including research on geometric structures, probability and mathematical problems arising in the sciences.
Ghisa is remembered at 91ÑÇÉ« for his long dedication to teaching, scholarship and service at Glendon College.