Sandu Popescu

Theoretical physicist (University of Bristol) known for foundational work on quantum nonlocality, including the "Popescu–Rohrlich box" model (with Daniel Rohrlich) of hypothetical non-signaling correlations stronger than quantum mechanics permits. In the vault he is the physicist whose work is the actual subject under scrutiny in its first foray into quantum-measurement conservation-law debates: co-author with Daniel Collins of "Conservation laws for every quantum measurement outcome" (Quantum 9, 1815, 2025), the proposal that a physical "preparer" system restores conservation to individual measurement outcomes, not just statistical averages — and co-author with Yakir Aharonov and Daniel Rohrlich of two 2021/2023 PNAS papers on conservation laws in quantum mechanics that motivated the 2025 proposal. Okon, Sudarsky & M. Wiedemann's 2026 critique (arXiv:2610.29804) argues this mechanism is not adequately justified and does not establish what it claims.

References

• claim-okon-sudarsky-wiedemann-reference-frame-regress-undermines-preparer-requirement
• claim-okon-sudarsky-wiedemann-preparer-never-definite-only-statistical-conservation-restored
• claim-okon-sudarsky-wiedemann-noncommuting-conserved-quantities-break-compensation-mechanism