Results 111 to 120 of about 3,155 (225)

Inverse Spectral Problems for Tridiagonal N by N Complex Hamiltonians

open access: yesSymmetry, Integrability and Geometry: Methods and Applications, 2009
In this paper, the concept of generalized spectral function is introduced for finite-order tridiagonal symmetric matrices (Jacobi matrices) with complex entries.
Gusein Sh. Guseinov
doaj   +1 more source

The Szegő condition for Coulomb Jacobi matrices

open access: yesJournal of Approximation Theory, 2003
A Jacobi matrix with $a_n\to 1$, $b_n\to 0$ and spectral measure $ν'(x)dx + dν_{sing}(x)$ satisfies the Szeg\H o condition if $\int_{0}^π\ln \bigl[ ν'(2\cosθ) \bigr] dθ$ is finite. We prove that if $a_n = 1 + \frac α{n} + O(n^{-1-\eps})$ and $b_n = \frac β{n} + O(n^{-1-\eps})$ with $2α\ge |β|$ and $\eps>0$, then the corresponding matrix is Szeg\H o.
openaire   +2 more sources

Dynamic inverse problem for Jacobi matrices

open access: yesInverse Problems and Imaging, 2019
We consider the inverse dynamical problem for the dynamical system with discrete time associated with the semi-infinite Jacobi matrix. We solve the inverse problem for such a system and answer a question on the characterization of the inverse data. As a by-product we give a necessary and sufficient condition for the measure on the real line line to be ...
Mikhaylov, A. S., Mikhaylov, V. S.
openaire   +3 more sources

Random Carbon Tax Policy and Investment Into Emission Abatement Technologies

open access: yesMathematical Finance, EarlyView.
ABSTRACT We analyze the problem of a profit‐maximizing electricity producer, subject to carbon taxes, who decides on investments into CO2$\rm CO_2$ abatement technologies. We assume that the carbon tax policy is random and that the investment in the abatement technology is divisible, irreversible, and subject to transaction costs.
Katia Colaneri   +2 more
wiley   +1 more source

Cantor spectrum of CMV matrices, Jacobi matrices and Schrodinger operators with dynamically defined coefficients and potentials [PDF]

open access: yes, 2020
In this thesis, we consider CMV matrices, Jacobi matrices and Schr\"{o}dinger operators while assuming that the coefficients and potentials are generated by dynamical systems. One of the major parts investigates continuous cocycles arising from CMV and
Jun, Hyunkyu
core  

A first-order spectral phase transition in a class of periodically modulated Hermitian Jacobi matrices [PDF]

open access: yesOpuscula Mathematica, 2008
We consider self-adjoint unbounded Jacobi matrices with diagonal \(q_n = b_{n}n\) and off-diagonal entries \(\lambda_n = n\), where \(b_{n}\) is a \(2\)-periodical sequence of real numbers. The parameter space is decomposed into several separate regions,
Irina Pchelintseva
doaj  

Rational points on even‐dimensional Fermat cubics

open access: yesTransactions of the London Mathematical Society, Volume 13, Issue 1, December 2026.
Abstract We show that even‐dimensional Fermat cubic hypersurfaces are rational over any field of characteristic not equal to three, by constructing explicit rational parameterizations with polynomials of low degree. As a byproduct of our rationality constructions, we obtain estimates for the number of their rational points over a number field and ...
Alex Massarenti
wiley   +1 more source

The reconstruction of a special kind of periodic Jacobi matrices [PDF]

open access: yes, 2012
In this paper, we investigate the properties of a special kind of periodic Jacobi matrices. We show that the solution of the inverse problem for periodic Jacobi matrices is unique if and only if the matrix is of that special kind. Moreover, we present an
Xu, Yinghong
core   +1 more source

On classical orthogonal polynomials and the Cholesky factorization of a class of Hankel matrices

open access: yesBulletin of Mathematical Sciences
Classical moment functionals (Hermite, Laguerre, Jacobi, Bessel) can be characterized as those linear functionals whose moments satisfy a second-order linear recurrence relation.
Misael E. Marriaga   +3 more
doaj   +1 more source

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