The Department of Mathematics mourns the loss of a dear colleague and former Department Chair, Professor William Arthur Kirk, who passed away on October 20, 2022.

Professor Kirk received his Bachelor’s degree from DePauw University in 1958 and his Ph.D. from the University of Missouri in 1962.  From 1962 to 1967, he was an Assistant Professor at the University of California at Riverside.  In 1967, he accepted the invitation to become an Associate Professor in the Department of Mathematics at the University of Iowa.  In 1970, he was promoted to the rank of Full Professor.  Between 1985 and 1991, Professor Kirk served as the Department Chair.  He retired in 2012, yet he kept active on research after the retirement.

Professor Kirk was an outstanding and internationally famous mathematician.  His research area was in Functional Analysis, especially fixed-point theory.  He is one of the founders of the modern theory of metric fixed-points, and his works influenced the development of the field decisively.  He is known for Kirk’s Fixed-Point Theorem of 1964/1965, published in the paper titled ``A fixed point theorem for mappings which do not increase distances’’ in Amer. Math. Monthly in 1965. He is also one of the two namesakes of the Caristi-Kirk Fixed-Point Theorem of 1976.  His achievements and leadership in the field were recognized by the title of Doctor Honoris Causa in 2004 from Maria Curie-Sklodowska University, Poland, which was an early center of study for the fixed-point theory of metric spaces.  Professor Kirk’s publications include three books and 177 journal articles.  His book ``Topics in Metric Fixed Point Theory’’, written jointly with K. Goebel and published by Cambridge University Press in 1990, is now a classic in the area of fixed-point theory.  According to MathSciNet, Professor Kirk’s work has been cited a whopping number of 4900 times by 1964 researchers.  ResearchGate.net lists 12,289 citations of his work.  Research.com named him as a best scientist from the Mathematics discipline.  He was an invited/plenary speaker in numerous international conferences.  Professor Kirk supervised thirteen Ph.D. theses. 

The following two journals will publish special issues to the memories of Professor Kirk and his close collaborator Professor Kazimierz Goebel:

Journal of Nonlinear and Convex Analysis (JNCA)

Fixed Point Theory and Algorithms for Sciences and Engineering (FPTASE)

Professor Kirk is survived by his wife Elizabeth A. McCartney; his children, Philip (Diana) Kirk, Malia (Whit) Lovelace and Brian (Tanner) Kirk; two grandchildren, Nicholas and Alexander Lovelace; his brother, Kenneth L. (Marion) Kirk and his aunt Rose Marie Pell.