Return to Colloquia & Seminar listing

### Kostka numbers and tensor product coefficients in A_r via polytopes.

**Algebra & Discrete Mathematics**

Speaker: | Charles Cochet, Universit{\'e} Paris 7, France |

Location: | 693 Kerr |

Start time: | Fri, Jan 9 2004, 12:10PM |

We apply some recent developments of Baldoni-Vergne and Baldoni-DeLoera-Vergne on vector partition functions, to Kostant's and Steinberg's formulas, in the case of the Lie algebra $A_r$. We therefore get a fast {\sc Maple} program that computes for $A_r$: the Kostka number, that is the multiplicity of a weight in a finite-dimensional irreducible representation; the Littlewood-Richardson coefficients, that is the coefficients of the decomposition of the tensor product of two finite-dimensional irreducible representations.