13,546 research outputs found

    Temperley-Lieb R-matrices from generalized Hadamard matrices

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    New sets of rank n-representations of Temperley-Lieb algebra TL_N(q) are constructed. They are characterized by two matrices obeying a generalization of the complex Hadamard property. Partial classifications for the two matrices are given, in particular when they reduce to Fourier or Butson matrices.Comment: 17 page

    Approximating Subadditive Hadamard Functions on Implicit Matrices

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    An important challenge in the streaming model is to maintain small-space approximations of entrywise functions performed on a matrix that is generated by the outer product of two vectors given as a stream. In other works, streams typically define matrices in a standard way via a sequence of updates, as in the work of Woodruff (2014) and others. We describe the matrix formed by the outer product, and other matrices that do not fall into this category, as implicit matrices. As such, we consider the general problem of computing over such implicit matrices with Hadamard functions, which are functions applied entrywise on a matrix. In this paper, we apply this generalization to provide new techniques for identifying independence between two vectors in the streaming model. The previous state of the art algorithm of Braverman and Ostrovsky (2010) gave a (1±ϔ)(1 \pm \epsilon)-approximation for the L1L_1 distance between the product and joint distributions, using space O(log⁥1024(nm)ϔ−1024)O(\log^{1024}(nm) \epsilon^{-1024}), where mm is the length of the stream and nn denotes the size of the universe from which stream elements are drawn. Our general techniques include the L1L_1 distance as a special case, and we give an improved space bound of O(log⁥12(n)log⁥2(nmÏ”)ϔ−7)O(\log^{12}(n) \log^{2}({nm \over \epsilon})\epsilon^{-7})

    Fast Hadamard transforms for compressive sensing of joint systems: measurement of a 3.2 million-dimensional bi-photon probability distribution

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    We demonstrate how to efficiently implement extremely high-dimensional compressive imaging of a bi-photon probability distribution. Our method uses fast-Hadamard-transform Kronecker-based compressive sensing to acquire the joint space distribution. We list, in detail, the operations necessary to enable fast-transform-based matrix-vector operations in the joint space to reconstruct a 16.8 million-dimensional image in less than 10 minutes. Within a subspace of that image exists a 3.2 million-dimensional bi-photon probability distribution. In addition, we demonstrate how the marginal distributions can aid in the accuracy of joint space distribution reconstructions

    Explicit Inversion for Two Brownian-Type Matrices

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    We present explicit inverses of two Brownian--type matrices, which are defined as Hadamard products of certain already known matrices. The matrices under consideration are defined by 3n−13n-1 parameters and their lower Hessenberg form inverses are expressed analytically in terms of these parameters. Such matrices are useful in the theory of digital signal processing and in testing matrix inversion algorithms.Comment: v3 has been submitted to Applied Mathematics (http://www.SciRP.org/journal/am) and accepted after revision; v4, i.e. the present version, is the revised E-print (title modified; some remarks and Eqs. (6)-(7) added in Sec. 1; Secs. 2 and 3 reformed; Sec. 5 added; References [6]-[7] added); 10 page

    Quantum Algorithms for Weighing Matrices and Quadratic Residues

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    In this article we investigate how we can employ the structure of combinatorial objects like Hadamard matrices and weighing matrices to device new quantum algorithms. We show how the properties of a weighing matrix can be used to construct a problem for which the quantum query complexity is ignificantly lower than the classical one. It is pointed out that this scheme captures both Bernstein & Vazirani's inner-product protocol, as well as Grover's search algorithm. In the second part of the article we consider Paley's construction of Hadamard matrices, which relies on the properties of quadratic characters over finite fields. We design a query problem that uses the Legendre symbol chi (which indicates if an element of a finite field F_q is a quadratic residue or not). It is shown how for a shifted Legendre function f_s(i)=chi(i+s), the unknown s in F_q can be obtained exactly with only two quantum calls to f_s. This is in sharp contrast with the observation that any classical, probabilistic procedure requires more than log(q) + log((1-e)/2) queries to solve the same problem.Comment: 18 pages, no figures, LaTeX2e, uses packages {amssymb,amsmath}; classical upper bounds added, presentation improve
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