What Can and What Cannot Be Done by LP and SDP (An Incomplete Overview)
summary
Gives a calculation-free proof of MRRW by projecting Krawtchouk polynomials to a degree-k space, forming a tridiagonal (Jacobi) operator and bounding its Perron eigenvalue to obtain |C| ≤ f(0)/f_0; derives Levenshtein by changing the measure to absorb 1−x, and links both to the Cohn‑Elkies sphere‑packing framework. Exhibits a polynomial proof of kissing number 12 with exact rational coefficients that tolerates few controlled violations. Notes exact few‑distance code sizes (two‑distance: 1 + C(n,2)), universal optimality of E8/Leech, and that SDP on triples does not beat LP asymptotically.
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chapters (6)
- 0:00Introduction
- 1:05LP and SDP overview
- 13:35Delsarte’s linear bound
- 27:13Kissing numbers
- 37:25LP and SDP limits
- 46:16Q&A
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