McKay conjecture
In mathematics, specifically in the field of group theory, the McKay conjecture is a theorem of equality between two numbers: the number of irreducible complex characters of degree not divisible by a prime number p {\displaystyle p} for a given finite group and the same number for the normalizer in that group of a Sylow p {\displaystyle p} -subgroup. It is named after the Canadian mathematician John McKay, who originally stated a limited version of it as a conjecture in 1971, for the special case of p = 2 {\displaystyle p=2} and simple groups.