Results 11 to 20 of about 1,319 (203)
Microclimate drives demographic compensation in a narrow endemic tropical species. [PDF]
New PhytolSummary Demographic compensation occurs when reductions in some vital rates are offset by increases in others, allowing populations to maintain similar performance across varying environments. This mechanism may help explain species' ecological distributions and range limits, yet its role at microenvironmental scales remains poorly understood.
Zupo T +10 more
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A Note on Reflectionless Jacobi Matrices [PDF]
Communications in Mathematical Physics, 2014 The property that a Jacobi matrix is reflectionless is usually characterized either in terms of Weyl m-functions or the vanishing of the real part of the boundary values of the diagonal matrix elements of the resolvent. We introduce a characterization in terms of stationary scattering theory (the vanishing of the reflection coefficients) and prove that
Jaksic, Vojkan +2 more
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An operational approach for solving fractional pantograph differential equation [PDF]
Iranian Journal of Numerical Analysis and Optimization, 2019 The aim of the current paper is to construct the shifted fractional-order Jacobi functions (SFJFs) based on the Jacobi polynomials to numerically solve the fractional-order pantograph differential equations. To achieve this purpose, first the operational
H. Ebrahimi, K. Sadri
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On the fine spectra of the Jacobi matrices on c_0,c,l_p (1≤p≤∞) and 〖bv〗_p (1≤p
Cumhuriyet Science Journal, 2021 The spectrum and spectral divisions of band matrices are very new and popular topics of studies. In this paper, our aims are to investigate boundedness of Jacobi matrix which is a band matrix has important role in physics and give subdivisions of the ...
Mustafa Yıldırım +2 more
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Reflectionless Herglotz Functions and Jacobi Matrices [PDF]
Communications in Mathematical Physics, 2008 A measure \(\mu\) on \(\mathbb R\) is said to be reflectionless on a compact set \(E \subset \mathbb R\) if its Stieltjes transform has purely imaginary boundary values almost everywhere on \(E\). If the set \(E\) is homogeneous, that is, there is \(\epsilon>0\) such that \(|E\cap(x-h,x+h)|>\epsilon h\) for all \(x\in E\) and \(h\in(0,\text{diam }E]\),
Poltoratski, Alexei, Remling, Christian
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Approximation Results for Reflectionless Jacobi Matrices [PDF]
International Mathematics Research Notices, 2010 We study spaces of reflectionless Jacobi matrices. The main theme is the following type of question: Given a reflectionless Jacobi matrix, is it possible to approximate it by other reflectionless and, typically, simpler Jacobi matrices of a special type? For example, can we approximate by periodic operators?
Poltoratski, Alexei, Remling, Christian
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A Comparison of Sequential and GPU Implementations of Iterative Methods to Compute Reachability Probabilities [PDF]
Electronic Proceedings in Theoretical Computer Science, 2012 We consider the problem of computing reachability probabilities: given a Markov chain, an initial state of the Markov chain, and a set of goal states of the Markov chain, what is the probability of reaching any of the goal states from the initial state ...
Elise Cormie-Bowins
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Spectral Estimates for Periodic Jacobi Matrices [PDF]
Communications in Mathematical Physics, 2003 We obtain bounds for the spectrum and for the total width of the spectral gaps for Jacobi matrices on $\ell^2(\Z)$ of the form $(H )_n= a_{n-1} _{n-1}+b_n _n+a_n _{n+1}$, where $a_n=a_{n+q}$ and $b_n=b_{n+q}$ are periodic sequences of real numbers. The results are based on a study of the quasimomentum $k(z)$ corresponding to $H$. We consider $k(z)$
Korotyaev, Evgeni, Krasovsky, Igor V.
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On the completely indeterminate case for block Jacobi matrices
Concrete Operators, 2017 We consider the infinite Jacobi block matrices in the completely indeterminate case, i. e. such that the deficiency indices of the corresponding Jacobi operators are maximal.
Osipov Andrey
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Relaxation parameters and composite refinement techniques
Results in Applied Mathematics, 2022 A composite refinement technique for two stationary iterative methods, one of them contains a relaxation parameter, is introduced. Four new techniques, Jacobi successive over relaxation (SOR) composite refinement (RJSOR), SOR Jacobi composite refinement (
Sh.A. Meligy, I.K. Youssef
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