Young symmetrizer

Etymology
Named after British mathematician Alfred Young.

Noun

 * 1)  An element of the group algebra of the symmetric group, constructed in such a way that, for the homomorphism from the group algebra to the endomorphisms of a vector space $$V^{\otimes n}$$ obtained from the action of $$S_n$$ on $$V^{\otimes n}$$ by permutation of indices, the image of the endomorphism determined by that element corresponds to an irreducible representation of the symmetric group over the complex numbers.