
Oliver Heaviside (1850  1925) was a selftaught physicist and mathematician who introduced complex numbers into circuit theory, invented the Laplacetransform approach to solving differential equations, first wrote Maxwell's equations in the form we now recognize, pioneered vector calculus... and incidentally discovered gauge invariance! [It took a long time to emerge in its modern form. For a thorough history, check here.] 
Yakir Aharonov (1932  ) 
A topological (Berry) phase. 