Induced sign representations and characters of Hecke algebras
introduction
- Many combinatorial formulas for computations in the symmetric group Sn can be modified appropriately to describe computations in the Hecke algebra Hn(q), a deformation of C[Sn].
induced sign characters
- Unfortunately, the known formulas for induced sign characters of Sn are not among these.
- For induced sign characters of Hn(q), we conjecture formulas which specialize at q=1 to formulas for induced sign characters of Sn.
- We will discuss evidence in favor of the conjecture, and relations to the chromatic quasi-symmetric functions of Shareshian and Wachs.
Given a partition \lambda=(\lambda_1,\cdots, \lambda_n) of n
1 define W_{\lambda}=S_{\lambda_1}\times S_{\lambda_2} \cdots \times S_{\lambda_k}
2 For each coset of the form wW_{\lambda},
define T_{wW_{\lambda}}=\sum_{v\in wW_{\lambda}}(-q)^{\ell(v)}T_{v}
If we set q=1, we get a sum looks like (\sum_{w\in W} w_{\lambda} sgn(v)v)
3 Let H_n(q) act by lefy multiplication on coset sums T_{D} where D is of the form wW_{\lambda}
4 this left multiplication can be expressed as matrix multiplication
Let \rho_{q}^{\lambda}(T_v)=matrix that correspondes to left multiplication by T_v.
Let \rho^{\lambda}(v)=matrix corresponding to left multiplication by v.
the trace/character associated to representation \rho_{q}^{\lambda} are usually denoted by \epsilon_{q}^{\lambda}
Q. What is a nice formula for \epsilon_{q}^{\lambda}(T_{v}) ? (open)
encyclopedia
- http://en.wikipedia.org/wiki/
- http://www.scholarpedia.org/
- http://eom.springer.de
- http://www.proofwiki.org/wiki/
expositions