Jacobson Density Theorem

A result in ring and module theory characterizing how a primitive ring acts on a simple module: a subring R of End_D(V) that acts faithfully and irreducibly on a right vector space V over a division ring D is dense in End_D(V) with respect to the finite‑topology determined by annihilators; equivalently R can approximate any D‑linear endomorphism on finite sets of vectors.