Entropy lower bounds for quantum decision tree complexity
β Scribed by Yaoyun Shi
- Publisher
- Elsevier Science
- Year
- 2002
- Tongue
- English
- Weight
- 70 KB
- Volume
- 81
- Category
- Article
- ISSN
- 0020-0190
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β¦ Synopsis
We prove a general lower bound of quantum decision tree complexity in terms of some entropy notion. We regard decision tree computation as a communication process in which the oracle and the computer exchange several rounds of messages, each round consisting of O(log n) bits. Let E(f ) be the Shannon entropy of the random variable f (X), where X is taken uniformly random in f 's domain. Our main result is that it takes (E(f )) queries to compute any total function f . It is interesting to contrast this bound with the (E(f )/ log n) bound, which is tight for some partial functions.
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