A polynomial identity for an algebra (or a ring) A is a polynomial in noncommutative variables that vanishes under any evaluation in A. An algebra satisfying a nontrivial polynomial identity is call a PI algebra, and this is the main object ...
... 2001 Edward Frenkel and David Ben-Zvi, Vertex algebras and algebraic curves, second edition, 2004 Bruno Poizat, Stable groups, 2001 Stanley N. Burris, Number theoretic density and logical limit laws, 2001 V. A. Kozlov, V. G. Maz'ya, ...