Boris Tsirelson

July 2026

Who he was

Boris Tsirelson (1950–2020) was a Soviet-born Israeli mathematician. In 1980 he proved the maximum possible violation of the CHSH inequality allowed by quantum mechanics — now called the Tsirelson bound.

What he’s known for on this site

The CHSH Inequality and the Tsirelson Bound sets the real ceiling on quantum correlation: local hidden-variable theories are bounded at CHSH$\le2$, while quantum mechanics allows violations up to $2\sqrt2\approx2.828$ — and never beyond it. This exact bound is what Paper 12 checks its own entanglement claims against.

Catalog status: Proven Systems

The Tsirelson bound is a proven mathematical consequence of quantum mechanics’ own structure, independently confirmed by every real Bell-test experiment to date.

Mentioned on this site

• CHSH Inequality and the Tsirelson Bound
• Paper 12

Where this touches PBT

Paper 7 cites a CHSH value “~2.82” for PBT’s own correlated-distortion entanglement mechanism, unsupported as stated — this site’s own established-physics cross-link makes clear that value is the real Tsirelson bound being approximated, not a number PBT’s mechanism has been shown to independently produce.