paper

Subadditivity of q-entropies for q>1

arXiv:0705.1276 · doi:10.1063/1.2771542

Abstract

I prove a basic inequality for Schatten q-norms of quantum states on a finite-dimensional bipartite Hilbert space H_1\otimes H_2: 1+||ρ||_q \ge ||\trace_1ρ||_q + ||\trace_2ρ||_q. This leads to a proof--in the finite dimensional case--of Raggio's conjecture (G.A. Raggio, J. Math. Phys.\ \textbf{36}, 4785--4791 (1995)) that the q-entropies S_q(ρ)=(1-\trace[ρ^q])/(q-1) are subadditive for q > 1; that is, for any state ρ, S_q(ρ) is not greater than the sum of the S_q of its reductions, S_q(ρ) \le S_q(\trace_1ρ)+S_q(\trace_2ρ).

2 pages

Cited by in corpus (17)