Ülo Lepik

Ülo Lepik (11 July 1921 – 12 February 2022) was an Estonian mathematician and mechanics researcher. He spent his academic career at the University of Tartu, where he became professor of theoretical mechanics and later professor emeritus, and he was elected a member of the Estonian Academy of Sciences in 1993.

Early life and education Lepik graduated from the Hugo Treffner Gymnasium in 1940 and began studies at the University of Tartu. His studies were interrupted twice during World War II.

In later life he applied chaos theory and wavelet methods—particularly Haar wavelets—to the solution of differential and integral equations, and co-authored a monograph published by Springer in 2014.

According to contemporary biographical notes and obituaries, he supervised 13 doctoral and candidate theses and published around 200 scientific articles and three monographs, in addition to university-level textbooks.

Selected works Lepik, Ü.; Roots, Lembit. Teoreetiline mehaanika. Valgus, 1971. (in Estonian) Lepik, Ü. Kaos ja kord. Tartu University Press, 1997. . (in Estonian) Lepik, Ü.; Engelbrecht, Jüri. Kaoseraamat. Teaduste Akadeemia Kirjastus, 1999. . (in Estonian) Lepik, Ü.; Hein, Helle. Haar Wavelets: With Applications. Springer, 2014.

Honours Order of the National Coat of Arms (4th class, 1998). National Research Award for outstanding lifetime achievements in research and development (2016).