The Cosmic Return Stroke: Star-Topology Channel Capacity and the Quantum Darwinist Resolution of the Fermi Paradox

We present a quantum-information-theoretic resolution to the Fermi Paradox grounded in Time-Symmetric Quantum Darwinism (TSQD). In prior work, we demonstrated that a self-consistent classical history requires a recursive fixed-point final boundary condition, ⟨Φ∗| = S[⟨Φ∗|], which selects macroscopic pointer states via high-redundancy, star-topology broadcast channels into the cosmic environment. Here, we analyze the channel capacity of a shared environmental bath E coupled to N independent macroscopic Von Neumann amplifiers (such as technological civilizations or high-gain observer nodes). Modeling cosmic history selection as a dielectric breakdown process in Hilbert space—where forward-time quantum branches act as stepped leaders and the backward-propagating final boundary acts as the return stroke—we prove a Star-Topology Crowding Theorem. When the number of macroscopic broadcasters exceeds a critical threshold Ncrit ∼ dim(HE)/Rmin, environmental sub-fractions overlap, violating the strict orthogonality of pointer records. Above Ncrit, the spectral gap of the fixed-point selection operator S collapses, degrading the sharp "return stroke" of classical einselection into a phase-scrambled "corona discharge" that destructively interferes in the cosmological path integral. Consequently, the Great Silence is not the result of biological rarity or sociological self-destruction, but of quantum dielectric quenching: self-consistent classical timelines are mathematically restricted to sparse, non-interfering distributions of macroscopic broadcasters. Finally, we propose a direct laboratory test of this topological crowding phase transition on multi-qubit superconducting quantum processors.