Can pulsar pair cascades supply the pairs inferred in pulsar wind nebulae
In plain words
Each charged particle pulled off a pulsar should create many pairs through cascades, and the nebulae around pulsars show how many pairs actually came out. Cascade models may fall short of the number some nebula models need.
Precise statement
Polar-cap cascade models give a maximum pair multiplicity $\kappa = n_{\mathrm{pairs}}/n_{\mathrm{GJ}}$ of a few times 1e5 (Timokhin and Harding 2019), where $n_{\mathrm{GJ}}$ is the Goldreich-Julian charge density, reached for the strongest fields and hottest surfaces in their model grid. Spectral models of the Crab nebula infer $\kappa$ of order 1e6 or more (moderate confidence). Determine whether polar-cap, outer-gap and current-sheet pair production together supply the nebular pair content inferred from radio to gamma-ray spectra, or whether the nebular inference must be revised.
What would settle it
Global kinetic magnetosphere models with QED pair creation giving total pair output, compared with nebula spectral models that constrain the injected pair number.