Stellar Dust: A Two-Epoch Interpretation of the Local Dynamical Discrepancy

It is proposed that part of the discrepancy between the locally measured dynamical mass and the luminous baryonic mass can be interpreted as a methodological inconsistency between two measurements performed at different cosmological epochs on different physical states of the same baryonic component. Primordial nucleosynthesis (BBN) and the cosmic microwave background (CMB) determine $\Omega_b h^2 \simeq 0.0224$ in a regime of hot plasma coupled to radiation. Dynamical measurements at $z = 0$ reflect the evolved state of that same component after $\sim 13.8$ Gyr of nonlinear evolution. It is argued that a fraction of the gravitational mass conventionally attributed to non-baryonic dark matter may correspond to baryons that have evolved into electromagnetically faint states. The model is illustrated with two extreme systems: ED-2, a primordial fossil without a recycling engine, and Sgr A*, an enriched system with active recycling.