dorsal/arxiv
View SchemaQuantum Lower Bound for the Collision Problem
| Authors | Scott Aaronson |
|---|---|
| Categories | |
| ArXiv ID | quant-ph/0111102 |
| URL | https://arxiv.org/abs/quant-ph/0111102 |
Abstract
The collision problem is to decide whether a function X:{1,..,n}->{1,..,n} is one-to-one or two-to-one, given that one of these is the case. We show a lower bound of Theta(n^{1/5}) on the number of queries needed by a quantum computer to solve this problem with bounded error probability. The best known upper bound is O(n^{1/3}), but obtaining any lower bound better than Theta(1) was an open problem since 1997. Our proof uses the polynomial method augmented by some new ideas. We also give a lower bound of Theta(n^{1/7}) for the problem of deciding whether two sets are equal or disjoint on a constant fraction of elements. Finally we give implications of these results for quantum complexity theory.
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"abstract": "The collision problem is to decide whether a function X:{1,..,n}-\u003e{1,..,n} is\none-to-one or two-to-one, given that one of these is the case. We show a lower\nbound of Theta(n^{1/5}) on the number of queries needed by a quantum computer\nto solve this problem with bounded error probability. The best known upper\nbound is O(n^{1/3}), but obtaining any lower bound better than Theta(1) was an\nopen problem since 1997. Our proof uses the polynomial method augmented by some\nnew ideas. We also give a lower bound of Theta(n^{1/7}) for the problem of\ndeciding whether two sets are equal or disjoint on a constant fraction of\nelements. Finally we give implications of these results for quantum complexity\ntheory.",
"arxiv_id": "quant-ph/0111102",
"authors": [
"Scott Aaronson"
],
"categories": [
"quant-ph",
"cs.CC"
],
"title": "Quantum Lower Bound for the Collision Problem",
"url": "https://arxiv.org/abs/quant-ph/0111102"
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