1846 – 1927
Gösta Mittag-Leffler (1846–1927) was a Swedish mathematician renowned for his foundational contributions to complex analysis and function theory. He founded the journal Acta Mathematica in 1882, which became one of the most prestigious mathematical publications in the world. Though primarily a mathematician, his work intersected with philosophy of mathematics, particularly regarding the status of geometric and analytic systems.
Proved the Mittag-Leffler theorem, a fundamental result in complex analysis on meromorphic function representations
Founded Acta Mathematica (1882), establishing a leading international mathematical journal
Advanced the Weierstrass program of rigorous function theory across Europe
Built extensive networks connecting European mathematicians, including championing Cantor's set theory
Contributed to conventionalist discussions on the epistemic status of mathematical and geometric systems