We give examples of finite string C -groups (the automorphism groups abstract regular polytopes) that have irreducible characters real Schur index 2. This answers a problem Monson concerning these groups.

In 1980, Lusztig posed the problem of showing the existence of a unipotent support for the irreducible characters of a nite reductive group G(F q ). This is de ned in terms of certain average values of the irreducible characters on unipotent classes. The problem was solved by Lusztig [16] for the case where q is a power of a su ciently large prime. In this paper we show that, in general, these ...

In this paper, we are interested in the question of separating two characters of the absolute Galois group of a number field K, by the Frobenius of a prime ideal p of OK . We first recall an upper bound for the norm N(p) of the smallest such prime p, depending on the conductors and on the degrees. Then we give two applications: (i) find a prime number p for which P (mod p) has a certain type of...

Let B be a reductive Lie subalgebra of a semi-simple Lie algebra F of the same rank both over the complex numbers. To each finite dimensional irreducible representation Vlambda of F we assign a multiplet of irreducible representations of B with m elements in each multiplet, where m is the index of the Weyl group of B in the Weyl group of F. We obtain a generalization of the Weyl character formu...

We show the intimate connection Schur functions have with the irreducible polynomial representations of GL(n,C). Following Schur’s thesis, in Section 1, we prove that the characters of these representations are given by Schur functions. In the second section, we elaborate on how a specific combinatorial operation on symmetric functions called plethysm gives the characters of the composition of ...

Let L = H(2r; n) be a graded Lie algebra of Hamiltonian type in the Cartan type series over an algebraically closed field of characteristic p > 2. In the generalized restricted Lie algebra setup, any irreducible representation of L corresponds uniquely to a (generalized) p-character χ. When the height of χ is no more than min{pni − pni−1 | i = 1, 2, . . . , 2r} − 2, the corresponding irreducibl...