The Experts below are selected from a list of 291 Experts worldwide ranked by ideXlab platform
S. Motta - One of the best experts on this subject based on the ideXlab platform.
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Polynomial Approximation of the lense thirring rigid precession frequency
Monthly Notices of the Royal Astronomical Society, 2018Co-Authors: Vittorio De Falco, S. MottaAbstract:We propose a Polynomial Approximation of the global Lense-Thirring rigid precession frequency to study low frequency quasi-periodic oscillations around spinning black holes. This high-performing Approximation allows to determine the expected frequencies of a precessing thick accretion disc with fixed inner radius and variable outer radius around a black hole with given mass and spin. We discuss the accuracy and the applicability regions of our Polynomial Approximation, showing that the computational times are reduced by a factor of $\approx70$ in the range of minutes.
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Polynomial Approximation of the Lense–Thirring rigid precession frequency
Monthly Notices of the Royal Astronomical Society, 2018Co-Authors: Vittorio De Falco, S. MottaAbstract:We propose a Polynomial Approximation of the global Lense-Thirring rigid precession frequency to study low frequency quasi-periodic oscillations around spinning black holes. This high-performing Approximation allows to determine the expected frequencies of a precessing thick accretion disc with fixed inner radius and variable outer radius around a black hole with given mass and spin. We discuss the accuracy and the applicability regions of our Polynomial Approximation, showing that the computational times are reduced by a factor of $\approx70$ in the range of minutes.
Vittorio De Falco - One of the best experts on this subject based on the ideXlab platform.
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Polynomial Approximation of the lense thirring rigid precession frequency
Monthly Notices of the Royal Astronomical Society, 2018Co-Authors: Vittorio De Falco, S. MottaAbstract:We propose a Polynomial Approximation of the global Lense-Thirring rigid precession frequency to study low frequency quasi-periodic oscillations around spinning black holes. This high-performing Approximation allows to determine the expected frequencies of a precessing thick accretion disc with fixed inner radius and variable outer radius around a black hole with given mass and spin. We discuss the accuracy and the applicability regions of our Polynomial Approximation, showing that the computational times are reduced by a factor of $\approx70$ in the range of minutes.
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Polynomial Approximation of the Lense–Thirring rigid precession frequency
Monthly Notices of the Royal Astronomical Society, 2018Co-Authors: Vittorio De Falco, S. MottaAbstract:We propose a Polynomial Approximation of the global Lense-Thirring rigid precession frequency to study low frequency quasi-periodic oscillations around spinning black holes. This high-performing Approximation allows to determine the expected frequencies of a precessing thick accretion disc with fixed inner radius and variable outer radius around a black hole with given mass and spin. We discuss the accuracy and the applicability regions of our Polynomial Approximation, showing that the computational times are reduced by a factor of $\approx70$ in the range of minutes.
Pencho Petrushev - One of the best experts on this subject based on the ideXlab platform.
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nonlinear piecewise Polynomial Approximation beyond besov spaces
Applied and Computational Harmonic Analysis, 2003Co-Authors: Borislav Karaivanov, Pencho PetrushevAbstract:Abstract We study nonlinear n-term Approximation in L p ( R 2 ) (0 R 2 which allow arbitrarily sharp angles. To characterize the rate of Approximation we introduce and develop three families of smoothness spaces generated by multilevel nested triangulations. We call them B-spaces because they can be viewed as generalizations of Besov spaces. We use the B-spaces to prove Jackson and Bernstein estimates for n-term piecewise Polynomial Approximation and consequently characterize the corresponding Approximation spaces by interpolation. We also develop methods for n-term piecewise Polynomial Approximation which capture the rates of the best Approximation.
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multivariate n term rational and piecewise Polynomial Approximation
Journal of Approximation Theory, 2003Co-Authors: Pencho PetrushevAbstract:We study nonlinear Approximation in Lp(Rd) (0 1) from (a) n-term rational functions, and (b) piecewise Polynomials generated by different anisotropic dyadic partitions of Rd. To characterize the rates of each such piecewise Polynomial Approximation we introduce a family of smoothness spaces (B-spaces) which can be viewed as an anisotropic variation of Besov spaces. We use the B-spaces to prove Jackson and Bernstein estimates and then characterize the piecewise Polynomial Approximation by interpolation. Our main estimate relates n-term rational Approximation with piecewise Polynomial Approximation in Lp(Rd). This result enables us to obtain a direct estimate for n-term rational Approximation in terms of a minimal B-norm (over all dyadic partitions). We also show that the Haar bases associated with anisotropic dyadic partitions of Rd can be successfully utilized for nonlinear Approximation. We give an effective algorithm for best Haar basis or best B-space selection.
Yoshihito Kazashi - One of the best experts on this subject based on the ideXlab platform.
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A fully discretised filtered Polynomial Approximation on spherical shells
Journal of Computational and Applied Mathematics, 2018Co-Authors: Yoshihito KazashiAbstract:A fully implementable filtered Polynomial Approximation on spherical shells is considered. The method proposed is a quadrature-based version of a filtered Polynomial Approximation. The radial direction and the angular direction of the shells are treated separately with constructive filtered Polynomial Approximation. The Approximation error with respect to the supremum norm is shown to decay algebraically for functions in suitable differentiability classes. Numerical experiments support the results
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A fully discretised Polynomial Approximation on spherical shells
GEM - International Journal on Geomathematics, 2016Co-Authors: Yoshihito KazashiAbstract:A fully discretised Polynomial Approximation on spherical shells is considered. The radial direction and the angular direction of the spherical shells are treated differently: for the radial direction, Polynomial interpolation is employed, whereas for the angular direction, hyperinterpolation is employed. The error in terms of a weighted $$L^2$$ L 2 -norm is bounded by the sum of two terms, one for the radial, one for the angular direction. Numerical results support our result.
Pradip Sircar - One of the best experts on this subject based on the ideXlab platform.
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multiresolution analysis using orthogonal Polynomial Approximation
European Signal Processing Conference, 1996Co-Authors: Rupendra Kumar, Pradip SircarAbstract:Multiresolution decomposition of signals has been conventionally carried out by the wavelet representation. In this paper, the orthogonal Polynomial Approximation has been employed for multiresolution analysis. It is demonstrated that the proposed technique based on Polynomial Approximation has certain distinct advantages over the conventional method employing wavelet representation.
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EUSIPCO - Multiresolution analysis using orthogonal Polynomial Approximation
1996Co-Authors: Rupendra Kumar, Pradip SircarAbstract:Multiresolution decomposition of signals has been conventionally carried out by the wavelet representation. In this paper, the orthogonal Polynomial Approximation has been employed for multiresolution analysis. It is demonstrated that the proposed technique based on Polynomial Approximation has certain distinct advantages over the conventional method employing wavelet representation.