Subadditivity of q-entropies for q>1

Koenraad M. R. Audenaert

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. T…