Boundary result · reduction to a published graph-capacity problem

FPRD-SH-B03

Nondivisible complement-of-Kneser policies retain a capacity gap

Exact statement

For the complete rr-uniform policy, Jψ=KGn,r‾J_\psi=\overline{KG_{n,r}}. If r∣nr\mid n, its capacity is n/rn/r; if r∤nr\nmid n, the one-shot packing ⌊n/r⌋\lfloor n/r\rfloor and fractional/Lovász ceiling n/rn/r diverge. The first complete two-support case is T5=KG5,2‾T_5=\overline{KG_{5,2}}, with published values α(T5⊠d)=2,5,12,27\alpha(T_5^{\boxtimes d})=2,5,12,27 for d=1,2,3,4d=1,2,3,4.

StatusExact reduction to the published triangular-graph capacity problem; no new capacity bound claimed
External reviewThe triangular-graph bounds are published; the FPRD policy translation has no external review.

Context

Kneser graphs themselves have capacity equal to their EKR independence number; their nondivisible complements retain a genuine one-shot-to-asymptotic gap.

Proof or evidence

The complete r-support policy has the complement Kneser overlap graph. For T5, supermultiplicativity gives 12*5=60 at power five and the standard recursive theta bound gives floor((5/2)*27)=67.

Verification notes

The complete two-support policy on five participants is verified to have the 10-vertex, 6-regular triangular conflict graph T5.

Limitations

  • The exact value of alpha(T5 strong-power 5) is not determined here.
  • The finite-attainment question is not open: nonattaining graphs have been known since 1990 and recent connected families are published.

Open work

Determine or tighten 60 <= alpha(T5 strong-power 5) <= 67 with symmetry-reduced XCC/DLX.