Results 71 to 80 of about 24,633 (240)
, 2000 An extension of the product operator formalism of NMR is introduced, which uses the Hadamard matrix product to describe many simple spin 1/2 relaxation processes. The utility of this formalism is illustrated by deriving NMR gradient-diffusion experiments
Bacon +35 more
core +2 more sources
, 2009 Louis W. Shapiro gave a combinatorial proof of a bilinear generating function for Chebyshev polynomials equivalent to the formula 1/(1-ax-x^2) * 1/(1-bx-x^2) = (1-x^2)/(1-abx-(2+a^2+b^2)x^2 -abx^3+x^4), where * denotes the Hadamard product. In a similar way, by considering tilings of a 2 by n rectangle with 1 by 1 and 1 by 2 bricks in the top row, and ...
openaire +3 more sources
Relativity and Hadamard products
, 2023 A key feature of Hadamard products is used to simplify relativistic matrix derivations.
openaire +1 more source
Quenching the Hubbard Model: Comparison of Nonequilibrium Green's Function Methods
Contributions to Plasma Physics, EarlyView.ABSTRACT We benchmark nonequilibrium Green's function (NEGF) approaches for interaction quenches in the half‐filled Fermi–Hubbard model in one and two dimensions. We compare fully self‐consistent two‐time Kadanoff–Baym equations (KBE), the generalized Kadanoff–Baym ansatz (GKBA), and the recently developed NEGF‐based quantum fluctuations approach (NEGF‐
Jan‐Philip Joost +3 more
wiley +1 more source
On Hadamard and Kronecker products in covariance structures for genotype × environment interaction
The Plant Genome, 2020 When including genotype × environment interactions (G × E) in genomic prediction models, Hadamard or Kronecker products have been used to model the covariance structure of interactions.
Johannes W. R. Martini +3 more
doaj +1 more source
, 2001 The noise kernel is the vacuum expectation value of the (operator-valued) stress-energy bi-tensor which describes the fluctuations of a quantum field in curved spacetimes.
A. Campos +57 more
core +1 more source
Enhancing Volatility Prediction: A Wavelet‐Based Hierarchical Forecast Reconciliation Approach
Journal of Forecasting, EarlyView.ABSTRACT Forecasting realized volatility (RV) has been widely studied, with numerous techniques developed to enhance predictive accuracy. Among these techniques, the use of RV decompositions based on intraday asset returns has been applied. However, the use of a frequency‐based decomposition, which provides unique insights into the dynamics of RV ...
Adam Clements, Ajith Perera
wiley +1 more source
Generalized Gram–Hadamard inequality [PDF]
, 2010 We generalize the classical Gram determinant inequality. Our generalization follows from the boundedness of the antisymmetric tensor product operator.
Constantinescu, Florin (Prof. Dr.) +1 more
core
Probability and Fourier duality for affine iterated function systems
, 2008 Let $d$ be a positive integer, and let $\mu$ be a finite measure on $\br^d$. In this paper we ask when it is possible to find a subset $\Lambda$ in $\br^d$ such that the corresponding complex exponential functions $e_\lambda$ indexed by $\Lambda$ are ...
Dutkay, Dorin Ervin, Jorgensen, Palle
core +3 more sources
On Regular Quaternary Hadamard Matrices
Journal of Combinatorial Designs, EarlyView.ABSTRACT Through the use of regularizing vectors, all regular quaternary Hadamard matrices of orders 10 and 18 have been successfully identified. Of these, two matrices of order 10 and 184 matrices of order 18 were found to have unbiased mates. Converting the quaternary Hadamard matrices of order 18 to real Hadamard matrices, the study uncovered that ...
Hadi Kharaghani +2 more
wiley +1 more source