Institute for Experimental Physics University of Vienna Institute for Quantum Optics and Quantum Information Austrian Academy of Sciences Mathematical Undecidability & Quantum Complementarity Časlav Brukner (in collaboration with Tomasz Paterek) Reykjavik, Iceland July 2007
Information-theoretical formulation of quantum physics: The most elementary system contains one bit of information. → Irreducible Randomness Zeilinger, 1999 Brukner, Zeilinger 2002 quant-ph/0212084 Information-theoretical formulation of Gödel’s theorem: If a theorem contains more information than a given set of axioms, then it is impossible for theorem to be derived from the axioms. Chaitin, 1982 Are the two related to each other?
Undecidability: Simple Example Axiom: “f(0)= 0” 1 bit Can be neither proved Theorem: “f(0)=0 and f(0) = f(1)”. nor disproved: needs 2 bits Theorem: “f(0)=0 and f(1)=0” Independent Statements: “f(0)= 0”, “f(1)= 0”, “f(0)=f(1)”
Closer look … 1 bit available → 3 logically complementary statements 1 2 3
„Experimental Test of Theorems“ 1 2 3 Axiom Theorem
How to represent mathematical functions physically?
Testing theorems using quantum mechanics
Testing Undecidable Theorems x y z State Preparation Measurement Bases 1. Systems give answers when asked (detectors “click”) 2. The question asked is undecidable → Random results! Is quantum randomness physical expression for mathematical undecidability?