dorsal/arxiv
View SchemaA simple formula for pooling knowledge about a quantum system
| Authors | Kurt Jacobs |
|---|---|
| Categories | |
| ArXiv ID | quant-ph/0503193 |
| URL | https://arxiv.org/abs/quant-ph/0503193 |
| DOI | 10.1103/PhysRevA.72.044101 |
| Journal | Phys. Rev. A 72, 044101 (2005) |
Abstract
When various observers obtain information in an independent fashion about a classical system, there is a simple rule which allows them to pool their knowledge, and this requires only the states-of-knowledge of the respective observers. Here we derive an equivalent quantum formula. While its realm of applicability is necessarily more limited, it does apply to a large class of measurements, and we show explicitly for a single qubit that it satisfies the intuitive notions of what it means to pool knowledge about a quantum system. This analysis also provides a physical interpretation for the trace of the product of two density matrices.
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"abstract": "When various observers obtain information in an independent fashion about a\nclassical system, there is a simple rule which allows them to pool their\nknowledge, and this requires only the states-of-knowledge of the respective\nobservers. Here we derive an equivalent quantum formula. While its realm of\napplicability is necessarily more limited, it does apply to a large class of\nmeasurements, and we show explicitly for a single qubit that it satisfies the\nintuitive notions of what it means to pool knowledge about a quantum system.\nThis analysis also provides a physical interpretation for the trace of the\nproduct of two density matrices.",
"arxiv_id": "quant-ph/0503193",
"authors": [
"Kurt Jacobs"
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"doi": "10.1103/PhysRevA.72.044101",
"journal_ref": "Phys. Rev. A 72, 044101 (2005)",
"title": "A simple formula for pooling knowledge about a quantum system",
"url": "https://arxiv.org/abs/quant-ph/0503193"
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