Results 11 to 20 of about 873 (53)

Perturbation of eigenvalues of matrix pencils and optimal assignment problem [PDF]

open access: yes, 2004
We consider a matrix pencil whose coefficients depend on a positive parameter $\epsilon$, and have asymptotic equivalents of the form $a\epsilon^A$ when $\epsilon$ goes to zero, where the leading coefficient $a$ is complex, and the leading exponent $A ...
Baccelli   +13 more
core   +5 more sources

Global structure of sign-changing solutions for discrete Dirichlet problems

open access: yesOpen Mathematics, 2020
Let T>1T\gt 1 be an integer, T≔[1,T]Z={1,2,…,T},Tˆ≔{0,1,…,T+1}{\mathbb{T}}:= {{[}1,T]}_{{\mathbb{Z}}}=\{1,2,\ldots ,T\},\hspace{.0em}\hat{{\mathbb{T}}}:= \{0,1,\ldots ,T+1\}.
Wei Liping, Ma Ruyun
doaj   +1 more source

Eigenfrequencies of generally restrained beams

open access: yesJournal of Applied Mathematics, Volume 2003, Issue 10, Page 503-516, 2003., 2003
We deal with the exact determination of eigenfrequencies of a beam with intermediate elastic constraints and generally restrained ends. It is the purpose of this paper to use the calculus of variations to obtain the equations of motion and the natural boundary conditions, and particularly those at the intermediate constraints.
Ricardo Oscar Grossi   +1 more
wiley   +1 more source

On a problem in eigenvalue perturbation theory [PDF]

open access: yes, 2015
We consider additive perturbations of the type $K_t=K_0+tW$, $t\in [0,1]$, where $K_0$ and $W$ are self-adjoint operators in a separable Hilbert space $\mathcal{H}$ and $W$ is bounded.
Gesztesy, Fritz   +2 more
core   +1 more source

Spectrum perturbations of compact operators in a Banach space

open access: yesOpen Mathematics, 2019
For an integer p ≥ 1, let Γp be an approximative quasi-normed ideal of compact operators in a Banach space with a quasi-norm NΓp(.) and the ...
Gil’ Michael
doaj   +1 more source

PT Symmetric Schr\"odinger Operators: Reality of the Perturbed Eigenvalues [PDF]

open access: yes, 2010
We prove the reality of the perturbed eigenvalues of some PT symmetric Hamiltonians of physical interest by means of stability methods. In particular we study 2-dimensional generalized harmonic oscillators with polynomial perturbation and the one ...
Caliceti, Emanuela   +2 more
core   +5 more sources

On a P\'olya functional for rhombi, isosceles triangles, and thinning convex sets [PDF]

open access: yes, 2019
Let $\Omega$ be an open convex set in ${\mathbb R}^m$ with finite width, and let $v_{\Omega}$ be the torsion function for $\Omega$, i.e. the solution of $-\Delta v=1, v\in H_0^1(\Omega)$.
Berg, M. van den   +3 more
core   +2 more sources

The Diagonalizable Nonnegative Inverse Eigenvalue Problem

open access: yesSpecial Matrices, 2018
In this articlewe provide some lists of real numberswhich can be realized as the spectra of nonnegative diagonalizable matrices but which are not the spectra of nonnegative symmetric matrices.
Cronin Anthony G, Laffey Thomas J.
doaj   +1 more source

Minimization of $\lambda_2(\Omega)$ with a perimeter constraint [PDF]

open access: yes, 2009
We study the problem of minimizing the second Dirichlet eigenvalue for the Laplacian operator among sets of given perimeter. In two dimensions, we prove that the optimum exists, is convex, regular, and its boundary contains exactly two points where the ...
Bucur, Dorin   +2 more
core   +4 more sources

Worst-case shape optimization for the Dirichlet energy [PDF]

open access: yes, 2016
We consider the optimization problem for a shape cost functional $F(\Omega,f)$ which depends on a domain $\Omega$ varying in a suitable admissible class and on a "right-hand side" $f$. More precisely, the cost functional $F$ is given by an integral which
Bellido, José Carlos   +2 more
core   +3 more sources

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