Results 11 to 20 of about 808,598 (165)
A Note on the Derivatives of Isotropic Positive Definite Functions on the Hilbert Sphere [PDF]
, 2019 In this note we give a recursive formula for the derivatives of isotropic positive definite functions on the Hilbert sphere. We then use it to prove a conjecture stated by Tr\"ubner and Ziegel, which says that for a positive definite function on the ...
Jäger, Janin
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Wiener’s problem for positive definite functions [PDF]
Mathematische Zeitschrift, 2017 We study the sharp constant $W_{n}(D)$ in Wiener's inequality for positive definite functions \[ \int_{\mathbb{T}^{n}}|f|^{2}\,dx\le W_{n}(D)|D|^{-1}\int_{D}|f|^{2}\,dx,\quad D\subset \mathbb{T}^{n}. \] N. Wiener proved that $W_{1}([- , ])
Gorbachev, D.V., Tikhonov, S.Y.
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Unitary representability of free abelian topological groups
Applied General Topology, 2008 For every Tikhonov space X the free abelian topological group A(X) and the free locally convex vector space L(X) admit a topologically faithful unitary representation. For compact spaces X this is due to Jorge Galindo.
Vladimir V. Uspenskij
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On average theta functions of certain quadratic forms as sums of Eisenstein series
Open Mathematics, 2023 Let QQ be an integral positive definite quadratic form of level NN in 2k2k variables. Further, we assume that (−1)kN{\left(-1)}^{k}N is a fundamental discriminant. We express the average theta function of QQ as an explicit sum of Eisenstein series, which
Eum Ick Sun
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Functional Calculus and Positive-Definite Functions [PDF]
Transactions of the American Mathematical Society, 1977 For a LCA group G with dual group Ĝ, let D ( G ) = D ( G ^ ) D(G) = D(\hat G) denote the convex (not closed) hull of { ⟨ x , γ ⟩ : x ∈ G , γ ∈
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The theory and applications of complex matrix scalings
Special Matrices, 2014 We generalize the theory of positive diagonal scalings of real positive definite matrices to complex diagonal scalings of complex positive definite matrices.
Pereira Rajesh, Boneng Joanna
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A New Theoretical Result for Quasi-Newton Formulae for Unconstrained Optimization [PDF]
Al-Rafidain Journal of Computer Sciences and Mathematics, 2005 The recent measure function of Byrd and Nocedal [3] is considered and simple proofs of some its properties are given. It is then shown that the AL-Bayati (1991) formulae satisfy a least change property with respect to this new measure .The new formula ...
Basim Hassan
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Modified projected Newton scheme for non-convex function with simple constraints [PDF]
Yugoslav Journal of Operations Research, 2021 In this paper, a descent line search scheme is proposed to find a local minimum point of a non-convex optimization problem with simple constraints. The idea ensures that the scheme escapes the saddle points and finally settles for a local minimum point ...
Chakraborty Suvra Kanti +1 more
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Isolated periodic wave trains in a generalized Burgers–Huxley equation
Electronic Journal of Qualitative Theory of Differential Equations, 2022 We study the isolated periodic wave trains in a class of modified generalized Burgers–Huxley equation. The planar systems with a degenerate equilibrium arising after the traveling transformation are investigated.
Qinlong Wang +3 more
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Strictly Hermitian positive definite functions [PDF]
Journal d'Analyse Mathématique, 2004 Let H be any complex inner product space with inner product . We say that f : C -->C is Hermitian positive definite on H if the matrix $$(f())_{r,s=1}^n \eqno(*)$$ is Hermitian positive definite for all choice of z^1,...,z^n in H, all n. It is strictly Hermitian positive definite if the matrix (*) is also non-singular for any choice of distinct z^1,.
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