original_query: What were some of Louis Nirenberg's contributions to the field of mathematics?
query: What were some of Louis Nirenberg's contributions to the field of mathematics?
answer: Louis Nirenberg's contributions include extending the Schauder theory to elliptic systems, using the maximum principle to prove symmetry of solutions to differential equations, making a seminal contribution to the Navier-Stokes equations, resolving the Minkowski problem in two dimensions, developing the Gagliardo-Nirenberg interpolation inequality, and proving the Newlander-Nirenberg theorem in complex geometry.