The story
Named after Finnish mathematician Lars Ahlfors (1907—1996), who published the theory in 1935.
Etymology from Wiktionary, CC BY-SA 4.0.
Ahlfors theory
Today it means: A geometric counterpart to Nevanlinna theory that extends the applicability of the concept of covering surface (of a topological space) by defining a covering number (a generalised "degree of covering") applicable to any bordered Riemann surface equipped with a conformal Riemannian metric. Full definition →