Can the Deconfined QCD Vacuum Be the Interior of a Gravastar?

An unreviewed, AI-assisted exploratory preprint by a non-physicist. It examines conditional gravitational configurations with an assumed particle-free interior of constant energy density B and pressure -B, motivated by the MIT bag-model vacuum analogy. The interpretation of that interior as a region of deconfined QCD vacuum is a modelling hypothesis. No formation, persistence or observational calculation is presented. The calculations reproduce and specialise established thin-shell gravastar analysis (Visser and Wiltshire 2004; Horvat and Ilijic 2007; Gaspar and Racz 2010). For the prescribed surface laws P = w sigma, the numerically evaluated marginal endpoints are R/(2M) = 1.46369 for w = 1/3, 1.30536 for w = 1/2, 1.15028 for w = 1 and 1.07446 for w = 2. The w = 1 value reproduces Gaspar and Racz; w = 2 violates the dominant energy condition and is a non-causal comparison. Strictly radially stable members of these shell families lie above their compactness endpoints and have 0 < M < M_end, with M_end depending on w and scaling as B^(-1/2); for the stiff shell M_end is 4.73 to 5.91 solar masses over the illustrative interval below, and 3.64 at the reference value B equal to the nuclear saturation energy density. The illustrative interval B^(1/4) = 145 to 162 MeV is the massless, non-interacting bag-model strange-matter stability window. It is a conditional parameter choice, not a measured interval for the energy density of an empty metastable QCD vacuum. Continuous anisotropic static stress profiles satisfying the null, weak and dominant energy conditions to numerical tolerance are constructed down to R/(2M) = 1.276. They have no derived material equation of state and no demonstrated dynamical stability or causality. The tested isotropic bag-fluid integrations from an empty-bag centre yield no regular free surface under the stated assumptions. No observational exclusion or support is claimed. No claim of priority is made. All calculations were carried out by an AI assistant (Claude, Anthropic) under the author's direction and reviewed by a second AI system with access to the code and earlier results. No human physicist has reviewed the work. The accompanying script archive contains six computational drivers, a run script, saved outputs, a table-to-script map, dependency versions and a change log; the reported numerical calculations in the manuscript are reproduced by it. Comments and corrections are welcome: [email protected].