Irreducible Representations of the Alternating Group in Odd Characteristic

Ben Ford

Proc. Amer. Math. Soc. 125 (1997), pp. 375-380 

Abstract. We use the recently-proved conjecture of Mullineux to determine which
modular irreducible representations of the symmetric group \Sigma_n split on 
restriction to A_n, and which remain irreducible (everything taking place over 
a splitting field for A_n of characteristic p > 2). An indexing of the 
absolutely irreducible representations of A_n is thus obtained. A modular 
analogue of the Frobenius symbol for a partition is introduced, which makes 
the Mullineux map somewhat more intuitive.