Black Particles in Information–Pressure Theory: Capacity-Saturated Gravitational Objects and the Dark Sector

Description: We show that dark matter phenomenology emerges naturally from capacity saturation of causal boundaries within Information–Pressure Theory (IPT). When a boundary saturates the entropy–area bound S = (kB/4Λ²)A, the admissible exterior algebra projects onto the gravitational sector alone—explaining gravity-only coupling without introducing new particle species. We define black particles (BPs) as microscopic saturated boundaries and derive their primordial abundance from first principles: fBP = 21/25 = 0.84, matching Planck's ΩDM/Ωm = 0.842 ± 0.006 within 0.3σ. A second formation channel—coherent edge collapse—produces stellar-mass black spheres (primordial black holes) contributing ~8% additional dark matter. The framework predicts void wall surface densities Σvac ≈ 13 M☉/pc² from the IPT saturation scale, matching observations with no free parameters. We present the complete spectral breakdown of Standard Model degrees of freedom on the boundary, resolving the tension between classical no-hair theorems and quantum unitarity: gauge hair exists but is washed out at saturation, preserving information while rendering it exterior-inaccessible. Seven independent tests using Draco dwarf spheroidal data all pass. The same boundary spectral structure that determines dark matter properties also fixes the cosmological constant (ΩΛ = 0.695) and fine structure constant (α⁻¹ = 137.024)—unifying dark sector physics with fundamental constants. Keywords: dark matter, Information-Pressure Theory, IPT, black particles, primordial black holes, capacity saturation, entropy bounds, Bekenstein bound, cosmology, no-hair theorem, boundary physics, void walls, dwarf spheroidals, Draco, dark sector, gravitational coupling, Standard Model, spectral geometry, cosmological constant, fine structure constant, quantum gravity, black holes, information paradox