Helper for Proposition 3.47: the associated ellipsoid volumes decay geometrically along the
ellipsoid recursion, relative to the initial radius-R ball.
Helper for Proposition 3.47: the same geometric ellipsoid-volume decay can be stated directly
in the ENNReal form required by Proposition 3.45.
Helper for Proposition 3.47: the accuracy budget forces the strict next-stage logarithmic
threshold and the final scalar decay estimate used to reach ε / M.
Helper for Proposition 3.47: the accuracy budget already implies the weaker logarithmic
threshold log (R / ρ) needed by Proposition 3.45.
Helper for Proposition 3.47: the same budget already guarantees a positive selected-feasible
count among the first N + 1 ellipsoid centers.
Helper for Proposition 3.47: every selected feasible sample among the first N + 1 queries
lies in the radius-R outer ball around xStar, so its pointwise localization measure is at most
R.
Helper for Proposition 3.47: every selected feasible sample among the first N + 1 queries
lies in the radius-R outer ball around xStar, so its pointwise localization measure is at most
R.
Helper for Proposition 3.47: a selected feasible sample whose value realizes the canonical best sampled prefix value yields the required raw queried center witness.
Companion owner theorem for Proposition 3.47: under the same hypotheses, the canonical best
sampled value along the selected feasible subsequence of queried centers in the first N + 1
queries is at most ε above the canonical constrained optimum problem.optimalValue. The
positivity of the selected-feasible prefix now follows from the same accuracy budget after the
small-accuracy bridge ε ≤ (M : ℝ) * R, and is not kept as a separate public premise.
Proposition 3.47 in source-facing form: under the logarithmic oracle budget, one of the
queried ellipsoid centers is an ε-approximate minimizer of the constrained problem.