Motivated by the recent progress on quantum integration, we study restricted Monte Carlo integration for anisotropic Hölder-Nikolskii classes. The results show that with c · log2n random bits we have the same optimal order for the n-th minimal Monte Carlo integration error as with arbitrary random numbers.
We obtain the optimal order of high-dimensional integration complexity in the quantum computation model in anisotropic Sobolev classes W∞r([0,1]d) and Hölder Nikolskii classes H∞r([0,1]d). It is proved that for these classes of functions there is a speed-up of quantum algorithms over deterministic classical algorithms due to factor n−1 and over randomized classical methods due to factor n−1/2. Moreover, we give an estimation for optimal query complexity in the class H∞Λ(D) whose smoothness index is the boundary of some complete set in Z+d.
We obtain the optimal order of high-dimensional integration complexity in the quantumcomputation model in anisotropic Sobolev classes W∞^r ([0, 1]^d) and Hǒlder Nikolskii classes H∞^r([0, 1]^d). It is proved that for these classes of functions there is a speed-up of quantum algorithms over deterministic classical algorithms due to factor n^-1 and over randomized classical methods due to factor n^-1/2. Moreover, we give an estimation for optimal query complexity in the class H∞^∧ (D) whose smoothness index is the boundary of some complete set in Z+^d.
We study the approximation of the integration of multivariate functions in the quantum model of computation. Using a new reduction approach we obtain a lower bound of the n-th minimal query error on anisotropic Sobolev classes B(Wpr([0, 1]d)), (r isin R+d). Then combining our previous results we determine the optimal bound of nth minimal query error for anisotropic Holder-Nikolskii class B(Hinfinr([0, 1]d)), (r isin R+d) and Sobolev class B(Wpr([0, 1]d)) (r isin Nd). The results show the quantum algorithms give speed up over classical algorithms.
We study a Monte Carlo algorithm that is based on a specific (randomly shifted and dilated) lattice point set. The main result of this paper is that the mean squared error for a given compactly supported, square-integrable function is bounded by n−1/2 times the L2-norm of the Fourier transform outside a region around the origin, where n is the expected number of function evaluations. As corollaries we obtain the order of convergence for the Sobolev spaces Hps with isotropic, anisotropic or mixed smoothness for all values of the parameters. This proves, in particular, that the optimal order of convergence in the latter case is n−s−1/2 for p≥2, which is, in contrast to the case of deterministic algorithms, independent of the dimension. This shows that Monte Carlo algorithms can improve the order by more than n−1/2 for a whole class of practically important function classes. All results carry over to functions defined on the unit cube without boundary conditions.