Let be a group and let be a graded representation of , i.e. a functor from to the category of graded vector spaces with each piece finite-dimensional. Thus acts on each graded piece individually, each of which is an ordinary finite-dimensional representation. We want to define a character associated to a graded representation, but if [...]
Archive for the ‘invariant theory’ Category
Introduction to symmetric functions
Posted in algebraic combinatorics, invariant theory, representation theory, tagged cycle indices, Hilbert series, representation theory of the symmetric group, symmetric functions on August 20, 2009 | 4 Comments »
The theory of symmetric functions, which generalizes some ideas that came up in the previous discussion of Polya theory, can be motivated by thinking about polynomial functions of the roots of a monic polynomial . Problems on high school competitions often ask for the sum of the squares or the cubes of the roots of [...]