Results 251 to 260 of about 3,344 (284)

Sums with convolutions of Dirichlet characters

manuscripta mathematica, 2010
Let \(\chi_1\) and \(\chi_2\) be primitive Dirichlet characters with conductors \(q_1\) and \(q_2\), respectively, and let \[ S_{\chi_1,\chi_2}(X):=\sum_{ab\leq X}\chi_1(a)\chi_2(b). \] The authors prove that if \(X\geq q_2^{\frac 23}\geq q_1^{\frac 23}\) and \(\log X=q_2^{o(1)}\), then \[ \left| S_{\chi_1,\chi_2}(X)\right|\leq X^{\frac {13}{18}}q_1 ...
Banks, William D., Shparlinski, Igor E.
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On Convoluted Numbers and Sums

The American Mathematical Monthly, 1967
(1967). On Convoluted Numbers and Sums. The American Mathematical Monthly: Vol. 74, No. 3, pp. 235-246.
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The convolution sums of MacMahon’s q-series

The Ramanujan Journal
In his classical work on partitions and divisor functions, MacMahon introduced the two \(q\)-series \(A_k(q)\) and \(C_k(q)\), which have since been shown to be quasimodular forms and are closely linked to partition functions, modular forms, and infinite product identities.
Xia, Ernest X. W., Fan, Yan, Yao, Olivia X. M.   +2 more
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Problem of Minimizing a Sum of Differences of Weighted Convolutions

Computational Mathematics and Mathematical Physics, 2020
In this paper the problem of minimizing a sum of differences of weighted convolutions is formulated as the problem of optimal summing of elements of two sequences where indices play the role of variables. It is shown that the considered problem can be interpreted as the problem that minimizes the sum of squared distances between the elements of an ...
Kel'manov, A. V., Mikhailova, L. V., Ruzankin, P. S., Khamidullin, S. A.   +3 more
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Computing the convolution and the Minkowski sum of surfaces

Proceedings of the 21st Spring Conference on Computer Graphics, 2005
In many applications, such as NC tool path generation and robot motion planning, it is required to compute the Minkowski sum of two objects. Generally the Minkowski sum of two rational surfaces cannot be expressed in rational form. In this paper we show that for LN spline surfaces (surfaces with a linear field of normal vectors) a closed form ...
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Ramanujan’s convolution sum twisted by Dirichlet characters

International Journal of Number Theory, 2019
We find formulas for convolutions of sum of divisor functions twisted by the Dirichlet character [Formula: see text], which are analogous to Ramanujan’s formula for convolution of usual sum of divisor functions. We use the theory of modular forms to prove our results.
Aygin, Zafer Selcuk, Hong, Nankun
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Non-Existence of Convolution Sum System Representations

IEEE Transactions on Signal Processing, 2019
Convolution sum system representations are commonly used in signal processing. It is known that the convolution sum, treated as the limit of its partial sums, can be divergent for certain continuous signals and stable linear time-invariant (LTI) systems, even when the convergence of the partial sums is treated in a distributional setting. In this paper,
Holger Boche, Ullrich J. Mönich, Bernd Meinerzhagen   +2 more
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Distributional Behavior of Convolution Sum System Representations

IEEE Transactions on Signal Processing, 2018
In this paper, we study the validity of the usual convolution sum sampling representation of linear time-invariant (LTI) systems. We consider continuous input signals with finite energy that are absolutely integrable and vanish at infinity. Even for these benign signals, the convolution sum does not always converge.
Holger Boche, Ullrich J. Mönich
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CONVOLUTIONS OF RAMANUJAN SUMS AND INTEGRAL CIRCULANT GRAPHS

International Journal of Number Theory, 2012
There exist several generalizations of the classical Dirichlet convolution, for instance the so-called A-convolutions analyzed by Narkiewicz. We shall connect the concept of A-convolutions satisfying a weak form of regularity and Ramanujan sums with the spectrum of integral circulant graphs.
Le, T. A., Sander, J. W.
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Evaluation of certain convolution sums involving the sum of the divisors function

The Ramanujan Journal, 2022
zbMATH Open Web Interface contents unavailable due to conflicting licenses.
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