QTT Color-Closure Confinement from Artian Center Sheets: Finite Color-Boundary Complex, No-Open-Color Gate, A6-Blocked String Tension

Confinement as a finite color-boundary closure gate Concept DOI: 10.5281/zenodo.20568652 Author: Ali Attar Website: quantumtraction.org Main book anchor: Quantum Traction Theory: Main Book v10.01 This paper frames confinement as a closure theorem before it is read as a force law. A color word must pass a finite triality boundary gate, and an isolated color charge fails that gate. The finite color complex is \[ 0\longrightarrow C_2^{\mathrm{col}} \xrightarrow{D_{\mathrm{col}}} C_1^{\mathrm{col}} \xrightarrow{\partial_{\mathrm{col}}} C_0^{\mathrm{col}} \longrightarrow0, \qquad C_0^{\mathrm{col}}=\mathbb Z_3. \] The physical color gate is \[ \mathcal H_{\mathrm{phys}}^{\mathrm{col}} \subseteq \ker \partial_{\mathrm{col}} \cap \mathcal H^{SU(3)\text{-inv}}, \qquad \partial_{\mathrm{col}}(X)=N_q(X)-N_{\bar q}(X)\pmod3. \] Thus \(q\bar q\), \(qqq\), \(\bar q\bar q\bar q\), and admissible adjoint singlet packets are closed, while a single quark is boundary-open. Core labels: Σ-COLOR-CLOSURE-FIREWALL, Σ-NO-OPEN-COLOR-GATE, Σ-CONFINEMENT-BY-HILBERT-SECTOR-EXCLUSION.