From information tasks to exclusivity and Bell bounds

Abstract

Can possible information tasks explain the quantum bound on Bell correlations? We obtain a conditional bound, without assuming a quantum state space, and identify the additional task requirements that recover the quantum value. Homogeneous frequency limits and common calibration domains imply consistent exclusivity. Completing two-copy parity measurements with an “other” outcome gives a Bell bound controlled by the weights of these residual records. Marletto’s T2 supplies four aligned parity sectors. A missing domain then requires an extra distinguishable label. An upper bound on readable labels, stable under adjoining spectators, and a reversible setting interchange remove the residual records. No-hypersignaling supplies this capacity bound when the relevant preparations are accessible and local signaling dimensions match the label counts. The result separates measurement existence, domain coverage, and readout weights.