Results 11 to 20 of about 477 (64)
Perturbation of eigenvalues of matrix pencils and optimal assignment problem [PDF]
, 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
On a problem in eigenvalue perturbation theory [PDF]
, 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
PT Symmetric Schr\"odinger Operators: Reality of the Perturbed Eigenvalues [PDF]
, 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
Global structure of sign-changing solutions for discrete Dirichlet problems
Open 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
Journal 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
A minimax principle for eigenvalues in spectral gaps: Dirac operators with Coulomb potentials.
Documenta Mathematica, 1999 We prove the minimax principle for eigenvalues in spectral gaps introduced in [5] based on an alternative set of hypotheses. In the case of the Dirac operator these new assumptions allow for potentials with Coulomb singularites.
M. Griesemer, R. Lewis, H. Siedentop
semanticscholar +1 more source
Worst-case shape optimization for the Dirichlet energy [PDF]
, 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
Spectrum perturbations of compact operators in a Banach space
Open 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
On a P\'olya functional for rhombi, isosceles triangles, and thinning convex sets [PDF]
, 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
Minimization of $\lambda_2(\Omega)$ with a perimeter constraint [PDF]
, 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