The mixing advantage is less than 2

Artikel i vetenskaplig tidskrift, 2009

Corresponding to n independent non-negative random variables X_1,...,X_n , are values M_1,...,M_n , where each M_i is the expected value of the maximum of n independent copies of X_i. We obtain an upper bound for the expected value of the maximum of X_1,...,X_n in terms of M_1,...,M_n . This inequality is sharp in the sense that the random variables can be chosen so that the bound is approached arbitrarily closely. We also present related comparison results.