Barbara Lee Keyfitz is a Canadian-American mathematician, the Dr. Charles Saltzer Professor of Mathematics at

Ohio State University The Ohio State University (Ohio State or OSU) is a public university, public Land-grant university, land-grant research university in Columbus, Ohio, United States. A member of the University System of Ohio, it was founded in 1870. It is one ...

. In her research, she studies nonlinear

partial differential equations In mathematics, a partial differential equation (PDE) is an equation which involves a multivariable function and one or more of its partial derivatives. The function is often thought of as an "unknown" that solves the equation, similar to how ...

and associated

conservation laws In physics, a conservation law states that a particular measurable property of an isolated physical system does not change as the system evolves over time. Exact conservation laws include conservation of mass-energy, conservation of linear momen ...

Professional career

Keyfitz did her undergraduate studies at the

University of Toronto The University of Toronto (UToronto or U of T) is a public university, public research university whose main campus is located on the grounds that surround Queen's Park (Toronto), Queen's Park in Toronto, Ontario, Canada. It was founded by ...

, and earned a Ph.D. in 1970 from

New York University New York University (NYU) is a private university, private research university in New York City, New York, United States. Chartered in 1831 by the New York State Legislature, NYU was founded in 1832 by Albert Gallatin as a Nondenominational ...

, under the supervision of

Peter Lax Peter David Lax (1 May 1926 – 16 May 2025) was a Hungarian-born American mathematician and Abel Prize laureate working in the areas of pure and applied mathematics. Lax made important contributions to integrable systems, fluid dynamics an ...

. Before taking her present position at

Ohio State The Ohio State University (Ohio State or OSU) is a public land-grant research university in Columbus, Ohio, United States. A member of the University System of Ohio, it was founded in 1870. It is one of the largest universities by enrollme ...

, she taught at

Columbia University Columbia University in the City of New York, commonly referred to as Columbia University, is a Private university, private Ivy League research university in New York City. Established in 1754 as King's College on the grounds of Trinity Churc ...

Princeton University Princeton University is a private university, private Ivy League research university in Princeton, New Jersey, United States. Founded in 1746 in Elizabeth, New Jersey, Elizabeth as the College of New Jersey, Princeton is the List of Colonial ...

Arizona State University Arizona State University (Arizona State or ASU) is a public university, public research university in Tempe, Arizona, United States. Founded in 1885 as Territorial Normal School by the 13th Arizona Territorial Legislature, the university is o ...

, and the

University of Houston The University of Houston (; ) is a Public university, public research university in Houston, Texas, United States. It was established in 1927 as Houston Junior College, a coeducational institution and one of multiple junior colleges formed in ...

; at Houston, she was the John and Rebecca Moores Professor of Mathematics. She was also the director of the

Fields Institute The Fields Institute for Research in Mathematical Sciences, commonly known simply as the Fields Institute, is an international centre for scientific research in mathematical sciences. It is an independent non-profit with strong ties to 20 Ontar ...

from 2004 to 2008. She was president of the

Association for Women in Mathematics The Association for Women in Mathematics (AWM) is a professional society whose mission is to encourage women and girls to study and to have active careers in the mathematical sciences, and to promote equal opportunity for and the equal treatment o ...

from 2005 to 2006, and in 2011 she became president of the

International Council for Industrial and Applied Mathematics The International Council for Industrial and Applied Mathematics (ICIAM) is an organisation for professional applied mathematics societies and related organisations. The current president is Wil Schilders. The cash award for each of the prizes is ...

. She was Vice-President of the

American Mathematical Society The American Mathematical Society (AMS) is an association of professional mathematicians dedicated to the interests of mathematical research and scholarship, and serves the national and international community through its publications, meetings, ...

from 2011 - 2014.

Awards and honors

Keyfitz is the 2005 winner of the

Krieger–Nelson Prize The Krieger–Nelson Prize is presented by the Canadian Mathematical Society in recognition of an outstanding woman in mathematics. It was first awarded in 1995. The award is named after Cecilia Krieger and Evelyn Nelson, both known for their contr ...

of the

Canadian Mathematical Society The Canadian Mathematical Society (CMS; French: ''Société mathématique du Canada'') is an association of professional mathematicians dedicated to advancing mathematical research, outreach, scholarship and education in Canada. The Society se ...

, the 2011

Noether Lecture The Noether Lecture is a distinguished lecture series that honors women "who have made fundamental and sustained contributions to the mathematical sciences". The Association for Women in Mathematics (AWM) established the annual lectures in 1980 as ...

r of the

,Barbara Keyfitz named 2012 Noether Lecturer

, retrieved 2020-05-21. the 2012 winner of the SIAM Prize for Distinguished Service to the Profession, and the 2012 AWM-SIAM Sonia Kovalevsky Lecturer. She was interviewed by Patricia Clark Kenschaft in her book ''Change is Possible:Stories of Women and Minorities in Mathematics''. In 2012 she became a fellow of the

. She is also a fellow of the

American Association for the Advancement of Science The American Association for the Advancement of Science (AAAS) is a United States–based international nonprofit with the stated mission of promoting cooperation among scientists, defending scientific freedom, encouraging scientific responsib ...

, the

Society for Industrial and Applied Mathematics Society for Industrial and Applied Mathematics (SIAM) is a professional society dedicated to applied mathematics, computational science, and data science through research, publications, and community. SIAM is the world's largest scientific soci ...

and the

. In 2017, she was selected as a fellow of the

in the inaugural class.

Publications

Books edited

*B. L. Keyfitz and H. C. Kranzer, eds., ''Nonstrictly Hyperbolic Conservation Laws'', Contemporary Mathematics, 60, American Mathematical Society, Providence, 1987. *B. L. Keyfitz and M. Shearer, eds., ''Nonlinear Evolution Equations that Change Type'', IMA Series Volume 27, Springer Verlag, 1990.

Book chapter

*B. L. Keyfitz, 'Hold that Light! Modeling of Traffic Flow by Differential Equations', in ''Six Themes on Variations'', (R. Hardt and R. Forman, eds), American Mathematical Society, 2005.

Selected publications in refereed journals

*B. L. Keyfitz, 'Solutions with shocks: an example of an L1 contractive semi-group', Comm. Pure Appl. Math. XXIV, (1971), 125-132. *B. L. Keyfitz, R. E. Melnik and B. Grossman, 'An analysis of the leading-edge singularity in transonic small-disturbance theory', Quarterly Journal of Mechanics and Applied Mathematics, XXXI, (1978), 137-155. *B. L. Keyfitz and H. C. Kranzer, 'Existence and uniqueness of entropy solutions to the Riemann problem for hyperbolic systems of two nonlinear conservation laws', Journal of Differential Equations, 27, (1978), 444-476. *B. L. Keyfitz and H. C. Kranzer, 'The Riemann problem for a class of hyperbolic conservation laws exhibiting a parabolic degeneracy', Journal of Differential Equations, 47, (1983), 35-65. *B. L. Keyfitz, 'Classification of one state variable bifurcation problems up to codimension seven', Dynamics and Stability of Systems, 1, (1986), 1-41. *B. L. Keyfitz and G. G. Warnecke, `The existence of viscous profiles for transonic shocks', Communications in Partial Differential Equations, 16, (1991) 1197-1221. *B. L. Keyfitz, 'A geometric theory of conservation laws which change type', Zeitschrift fur Angewandte Mathematik und Mechanik, 75, (1995), 571-581. *B. L. Keyfitz and N. Keyfitz, 'The McKendrick Partial Differential Equation and its Uses in Epidemiology and Population Study', Mathematical and Computer Modelling, 26, (1997), 1-9. *B. L. Keyfitz, 'Self-Similar Solutions of Two-Dimensional Conservation Laws', Journal of Hyperbolic Differential Equations, 1 (2004), 445-492. *B. L. Keyfitz, 'The Fichera Function and Nonlinear Equations', Rendiconti Accademia delle Scienze detta dei XL, Memorie di Matematica e Applicazioni, XXX (2006), 83-94. *B. L. Keyfitz, 'Singular Shocks: Retrospective and Prospective', Confluentes Mathematici, 3 (2011), 445-470. *J. Holmes, B. L. Keyfitz and F. Tiglay, 'Nonuniform dependence on initial data for compressible gas dynamics: The Cauchy problem on R2', SIAM Journal of Mathematical Analysis, 50 (2018), 1237-1254.

Personal

Keyfitz was born in

Ottawa Ottawa is the capital city of Canada. It is located in the southern Ontario, southern portion of the province of Ontario, at the confluence of the Ottawa River and the Rideau River. Ottawa borders Gatineau, Gatineau, Quebec, and forms the cor ...

, and is the daughter of Canadian demographer Nathan Keyfitz. She is married to Marty Golubitsky and has two children.

References

{{DEFAULTSORT:Keyfitz, Barbara Lee Year of birth missing (living people) Living people 20th-century American mathematicians 21st-century American mathematicians Canadian mathematicians Canadian women academics Courant Institute of Mathematical Sciences alumni Columbia University faculty Princeton University faculty Arizona State University faculty University of Houston faculty Ohio State University faculty Fellows of the American Mathematical Society Fellows of the American Association for the Advancement of Science Fellows of the Society for Industrial and Applied Mathematics Fellows of the Association for Women in Mathematics 20th-century American women mathematicians 21st-century American women mathematicians