scispace - formally typeset
Open AccessJournal ArticleDOI

Polynomial degree vs. quantum query complexity

Andris Ambainis
- Vol. 72, Iss: 2, pp 220-238
Reads0
Chats0
TLDR
In this paper, the first superlinear separation between polynomial degree and quantum query complexity was shown by a more general version of the quantum adversary method, and the lower bound was shown to be tight.
Abstract
The degree of a polynomial representing (or approximating) a function f is a lower bound for the quantum query complexity of f. This observation has been a source of many lower bounds on quantum algorithms. It has been an open problem whether this lower bound is tight. We exhibit a function with polynomial degree M and quantum query complexity (M/sup 1.321.../). This is the first superlinear separation between polynomial degree and quantum query complexity. The lower bound is shown by a new, more general version of quantum adversary method.

read more

Citations
More filters
Book

Analysis of Boolean Functions

TL;DR: This text gives a thorough overview of Boolean functions, beginning with the most basic definitions and proceeding to advanced topics such as hypercontractivity and isoperimetry, and includes a "highlight application" such as Arrow's theorem from economics.
Proceedings ArticleDOI

Quantum algorithms for the triangle problem

TL;DR: Two new quantum algorithms are presented that either find a triangle (a copy of K3) in an undirected graph or reject if it is triangle free, and they are based on a new design concept of Ambainis.
Proceedings ArticleDOI

Negative weights make adversaries stronger

TL;DR: A stronger version of the adversary method, called ADV+-, was proposed in this article, which goes beyond this principle to make explicit use of the stronger condition that the algorithm actually computes the function.
Journal ArticleDOI

Polynomial Degree and Lower Bounds in Quantum Complexity: Collision and Element Distinctness with Small Range

TL;DR: A general method for proving quantum lower bounds for problems with small range is given, and a better lower bound is obtained on the polynomial degree of the two-level AND-OR tree.
Proceedings ArticleDOI

Any AND-OR Formula of Size N can be Evaluated in time N^{1/2 + o(1)} on a Quantum Computer

TL;DR: It follows that the (2-o(1))th power of the quantum query complexity is a lower bound on the formula size, almost solving in the positive an open problem posed by Laplante, Lee and Szegedy.
References
More filters
Journal ArticleDOI

Polynomial-Time Algorithms for Prime Factorization and Discrete Logarithms on a Quantum Computer

TL;DR: In this paper, the authors considered factoring integers and finding discrete logarithms on a quantum computer and gave an efficient randomized algorithm for these two problems, which takes a number of steps polynomial in the input size of the integer to be factored.
Proceedings ArticleDOI

A fast quantum mechanical algorithm for database search

TL;DR: In this paper, it was shown that a quantum mechanical computer can solve integer factorization problem in a finite power of O(log n) time, where n is the number of elements in a given integer.
Book

Introduction to approximation theory

TL;DR: In this paper, Tchebycheff polynomials and other linear families have been used for approximating least-squares approximations to systems of equations with one unknown solution.
Journal ArticleDOI

Strengths and Weaknesses of Quantum Computing

TL;DR: It is proved that relative to an oracle chosen uniformly at random with probability 1 the class $\NP$ cannot be solved on a quantum Turing machine (QTM) in time $o(2^{n/2})$.
Journal ArticleDOI

Complexity measures and decision tree complexity: a survey

TL;DR: Several complexity measures for Boolean functions are discussed: certificate complexity, sensitivity, block sensitivity, and the degree of a representing or approximating polynomial, and how they give bounds for the decision tree complexity of Boolean functions on deterministic, randomized, and quantum computers.
Related Papers (5)