New lower bounds for binary constant-weight codes: $A(23,6,10)\geq 2979$ and $A(24,6,10)\geq 4214$
This work addresses the long-standing open problem of constructing optimal binary constant-weight codes by introducing a novel coordinate decomposition approach. The method fixes half of the coordinates using known codewords and selects the remaining half from a fully cross-compatible pool, then employs the CHILS algorithm to solve a maximum-weight independent set problem to construct larger codes. The maximality of the resulting codes is verified using two exact solvers, and symmetry analysis of prime-order permutation-invariant codes eliminates redundant structures. This strategy breaks the lower bound records that had remained unimproved since 1990, establishing new results: $A(23,6,10) \geq 2979$ and $A(24,6,10) \geq 4214$, while also improving the known lower bounds for $A(23,6,11)$ and $A(24,6,8)$. All new bounds have been incorporated into Brouwer’s online table.