Self-Interacting Dark Matter as the Fragile 0-State Condensate of the Quantum Mirror Hypothesis

This preprint presents a geometric mechanism for self-interacting dark matter (SIDM) within the Quantum Mirror Hypothesis (QMH) framework. The vacuum is modelled as a near-perfect 0-state mirror grid whose small flaws ε drive emergent physics. Dark matter arises naturally as fragile, magnetically sensitive condensates of near-0-state regions. Mirror-repair dynamics (flaw accumulation and κ-restoration) generate a velocity-dependent self-interaction cross-section σ/m ∝ v⁻². This scaling matches dwarf-galaxy core requirements (σ/m ≈ 10–100 cm²/g at v ≈ 10–50 km/s) while automatically satisfying Bullet Cluster constraints (σ/m < 0.7 cm²/g at cluster velocities) without new particles or forces. A simplified gravothermal simulation with physically motivated Ornstein–Uhlenbeck modulation of the cross-section yields a null result for the history-dependent piece, reported honestly as a constraint. The core v⁻² claim remains intact. Full quantitative gravothermal stability and first-principles derivation of κ from ε are deferred to future work. This paper is the direct companion to “The Quantum Mirror Hypothesis: A Geometric Origin for Baryon CP Violation” (Zenodo, April 2026). Both works share the single QMH postulate and the same flaw parameter ε ≈ 0.012. Keywords: self-interacting dark matter, SIDM, core-cusp problem, velocity-dependent cross-section, Quantum Mirror Hypothesis, gravothermal collapse, dark matter condensate See the full paper for detailed limitations, testable predictions (including magnetic sensitivity via the South Atlantic Anomaly), and references.