Peter D. Lax's life story is part of both Hungarian scientific history and the global history of modern mathematics – Bálint Tóth, research professor at Rényi Institute, reflects on Peter D. Lax1s personality and his belief in the unity of mathematics.
Peter D. Lax was one of the most influential mathematicians of the 20th century: a scientist who helped shape modern theoretical mathematics, computational modeling, and the applied sciences alike. His work contributed to the development of mathematical methods that are now indispensable in fields ranging from weather forecasting and aircraft design to the simulation of fluids and gases, as well as the modernization of telecommunications.
The life of the Budapest-born mathematician also mirrors the history of the 20th century itself. Born in Budapest in 1926, his family fled to the United States in 1941 to escape the anti-Jewish laws in Hungary. He earned his degree at New York University, and his scientific career centered around the university’s legendary Courant Institute of Mathematical Sciences. He served as professor there from 1958 onward, and between 1972 and 1980 he also directed the institute, now called Courant Institute School of Mathematics, Computing and Data Science.
In Peter D. Lax, the ideal that there is no sharp boundary between pure (theoretical) and applied mathematics truly came to life. As Bálint Tóth, research professor at the Probability and Statistics Department of Rényi Institute, emphasized in an interview on Kossuth Radio, Lax was both the creator of great mathematical theories and one of the foremost experts in the development of highly applicable methods. The interview can be listened to HERE (in Hungarian).
Lax often stressed the importance of actively nurturing the relationship between pure and applied mathematics, believing that theoretical ideas and practical problem-solving continuously inspire one another. This way of thinking contributed greatly to the rise of the Courant Institute into one of the world’s leading centers of mathematics in the second half of the 20th century.
Many foundational results of modern applied mathematics are associated with Peter D. Lax's name. His research brought breakthroughs in partial differential equations, fluid dynamics, numerical methods, and computational mathematics. Mathematicians know his name through concepts such as the Lax–Milgram theorem, the Lax–Friedrichs and Lax–Wendroff methods, and the theory of Lax pairs. The impact of his work is also present in everyday technologies: beyond the applications mentioned above, computational fluid dynamics simulations and engineering models often rely on mathematical methods whose development was pioneered by Peter D. Lax.
| In 2005 he received the Abel Prize – referred to as the Nobel Prize in mathematics – in recognition of his scientific and teaching achievements, especially his fundamental contributions to the theory, applications, and numerical solutions of partial differential equations. Earlier he had also been awarded the Wolf Prize and the Steele Prize, and in 1993 he was elected an honorary member of the Hungarian Academy of Sciences. |
His career was profoundly influenced by his mentor Richard Courant, who supervised his doctoral work and later guided him as a senior advisor. His professional development was also shaped by renowned Hungarian mathematicians such as Rózsa Péter, Dénes Kőnig, and Pál Turán, as well as by his uncle Albert Korodi. In the United States he also came into contact with John von Neumann and Paul Erdős. Some even said that he was von Neumann’s only student.
Although he spent most of his life in the United States, he preserved his Hungarian identity throughout his life. Beginning in 1962, he returned regularly to Budapest, where several of his relatives still lived. He delivered lectures in Hungarian at institutions including Alfréd Rényi Institute of Mathematics and other Hungarian universities and research centers. He also participated in developing the doctoral program in mathematics at CEU. His work as a teacher and community builder influenced generations of mathematicians.
His intellectual culture was legendary: he could quote Hungarian poets from memory, and his favorite writer was Mór Jókai. Alongside mathematics, art and sports also played an important role in his life. He wrote poetry in both Hungarian and English and regularly read Hungarian novels. He was deeply passionate about and highly knowledgeable in classical music, painting, and sculpture, while also being known as an excellent tennis player and skier.
| Professor Bálint Tóth is organizing the conference held in memory of Lax Péter at Alfréd Rényi Institute of Mathematics. The event, taking place on September 21, 2026, in the Institute’s Main Hall, will also present the work of Hungarian researchers whose findings are closely related to Peter D. Lax’s mathematical achievements. |
Péter Lax passed away on May 16, 2025, in his 99th year. Yet his legacy lives on in many areas of modern mathematics and in the enduring idea that theoretical thinking and the understanding of real-world problems are not separate, but parts of the same scientific endeavor.