Baryon-to-Photon Ratio (Emergent)

The baryon-to-photon ratio η ≈ 6.1 × 10⁻¹0 is a dimensionless number that must be set as an initial condition in ΛCDM — there is no internal mechanism that predicts its value, and it can only be inferred by fitting the CMB acoustic peak positions and the BBN light element abundances. In ΛCDM, η is tied to baryogenesis, a process that must have generated a one-part-in-ten-billion excess of matter over antimatter from an initially symmetric state, a mechanism for which there is no confirmed theory. Successive Collision Theory reframes the origin of η as an emergent outcome of the collision kinematics rather than a baryogenesis miracle. The two parent pockets that collided to produce our observable universe were not symmetric matter-antimatter systems — they were pre-existing spacetime regions with their own matter content, themselves products of prior cosmic history in an eternal universe. The ratio of baryons to photons in the thermalized plasma is therefore the ratio of the baryon number density of the colliding matter to the photon density produced by thermalizing the kinetic energy of the collision.

Both quantities are determined by the physical state of the colliding pockets and the collision energy, not by any symmetry-breaking phase transition occurring instantaneously at t=0. The specific value η ≈ 6 × 10⁻¹0 is consistent with the matter density typical of regions that have been forming stars and recycling material through multiple stellar generations — precisely what SCT's pre-existing matter picture predicts for the parent pockets. The photon density is set by thermalizing the relative kinetic energy of the collision, which for pockets of the observed mass-energy density colliding at superluminal relative velocity produces a plasma temperature consistent with T ~ 10³² K at the relevant epoch. The baryon-to-photon ratio in SCT is therefore not an unexplained parameter but a calculable consequence of the collision geometry and the pre-existing matter state of the parent pockets — a thermodynamic output of the event rather than an inexplicable initial condition.