{
"$type": "site.standard.document",
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"uri": "at://did:plc:4rgrdigiftglskeax4wvmsev/app.bsky.feed.post/3mevb5rd7kre2"
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"path": "/report/2026/019",
"publishedAt": "2026-02-15T07:27:54.000Z",
"site": "https://eccc.weizmann.ac.il",
"textContent": "We prove that for any 3-player game $\\mathcal G$, whose query distribution has the same support as the GHZ game (i.e., all $x,y,z\\in \\\\{0,1\\\\}$ satisfying $x+y+z=0\\pmod{2}$), the value of the $n$-fold parallel repetition of $\\mathcal G$ decays exponentially fast: \\\\[ \\text{val}(\\mathcal G^{\\otimes n}) \\leq \\exp(-n^c)\\\\] for all sufficiently large $n$, where $c>0$ is an absolute constant. We also prove a concentration bound for the parallel repetition of the GHZ game: For any constant $\\epsilon>0$, the probability that the players win at least a $\\left(\\frac{3}{4}+\\epsilon\\right)$ fraction of the $n$ coordinates is at most $\\exp(-n^c)$, where $c=c(\\epsilon)>0$ is a constant. In both settings, our work exponentially improves upon the previous best known bounds which were only polynomially small, i.e., of the order $n^{-\\Omega(1)}$. Our key technical tool is the notion of \\emph{algebraic spreadness} adapted from the breakthrough work of Kelley and Meka (FOCS '23) on sets free of 3-term progressions.",
"title": "TR26-019 | Improved Parallel Repetition for GHZ-Supported Games via Spreadness | \n\n\tShachar Lovett, \n\n\tYang P. Liu, \n\n\tKunal Mittal"
}