Blinded (left) and unblinded (right) PDFs for D _{Δ t} , showing the RXJ1131−1231 posterior constraints on D _{Δ t} (solid) given assorted priors for the cosmological parameters (dotted, labeled). See Table 2 for a full description of the various priors. RXJ1131−1231 provides tight constraints on D _{Δ t} , which translates into information about Ω _m, Ω _de, w, and particularly H ₀.