Certified astrophysical nulls

Let ${\Theta }_{\mathrm{sc}}$ be the declared uncertainty class of semiclassical channels, including legitimate preparation, background, capture, and access uncertainties. Define

This is the astrophysical null. It equals $1/2$ only under a proved message-independence statement, and it is not set to $3/4$ unless the complete trusted-input measure-before-query null is separately imposed.