The filtered topology of the D_9^+ void
Grow balls of squared radius t about the points of D_9^+ = D_9 ∪ ((1/2)^9 + D_9), with contact distance √2, and follow the uncovered part of the torus R^9/D_9 as t falls from the squared covering radius 17/16 to 0. Its persistent homology has 37 critical levels and 55 classes of bars. It is the same over the rationals...