Results 31 to 40 of about 510 (80)

A conic manifold perspective of elliptic operators on graphs

, 2007
We give a simple, explicit, sufficient condition for the existence of a sector of minimal growth for second order regular singular differential operators on graphs. We specifically consider operators with a singular potential of Coulomb type and base our
Birkhoff, Engel, Gerardo A. Mendoza, Gil, Gil, Gil, Juan B. Gil, Kostrykin, Kostrykin, Kuchment, Lesch, Savchuk, Schulze, Thomas Krainer, von Below   +14 more
core   +1 more source

Inverse Spectral Problems for Schr\"odinger-Type Operators with Distributional Matrix-Valued Potentials [PDF]

, 2015
The principal purpose of this note is to provide a reconstruction procedure for distributional matrix-valued potential coefficients of Schr\"odinger-type operators on a half-line from the underlying Weyl-Titchmarsh function.Comment: 14 pages. arXiv admin
Eckhardt, Jonathan, Gesztesy, Fritz, Nichols, Roger, Sakhnovich, Alexander, Teschl, Gerald   +4 more
core   +2 more sources

Bounds and optimization of the minimum eigenvalue for a vibrating system

, 2013
We consider the problem of the oscillation of a string fixed at one end with a mass connected to a spring at the other end. The problem of minimizing the first eigenvalue of the system subject to a fixed total mass constraint is investigated.
D. Hinton, Maeve L. McCarthy
semanticscholar   +1 more source

Non-homogeneous BVPs for second-order symmetric Hamiltonian systems

Open Mathematics
By making use of Bolle’s method, we show that the following problem has infinitely many solutions: x¨+V′(x)=0,x(0)cosα−x˙(0)sinα=x0,x(1)cosβ−x˙(1)sinβ=x1,\begin{array}{rcl}\ddot{x}+{V}^{^{\prime} }\left(x)& =& 0,\\ x\left(0)\cos \alpha -\dot{x}\left(0 ...
Chen Yingying, Dong Yujun, Wang Baiqian
doaj   +1 more source

Self-adjoint boundary conditions and interlacing of eigenvalues for the Sturm-Liouville equation on graphs

, 2014
Applying the approach of Kostrykin and Schrader, [14], an explicit characterisation of self-adjoint boundary conditions at the nodes or vertices of a graph for the Sturm-Liouville equation is given.
S. Currie
semanticscholar   +1 more source

Boundary value problems for integro-differential and singular higher-order differential equations

Open Mathematics
We investigate third-order strongly nonlinear differential equations of the type (Φ(k(t)u″(t)))′=f(t,u(t),u′(t),u″(t)),a.e. on[0,T],\left(\Phi \left(k\left(t){u}^{^{\prime\prime} }\left(t)))^{\prime} =f\left(t,u\left(t),u^{\prime} \left(t),{u}^{^{\prime ...
Anceschi Francesca, Calamai Alessandro, Marcelli Cristina, Papalini Francesca   +3 more
doaj   +1 more source

Real and non-real eigenvalues of regular indefinite Sturm–Liouville problems

Open Mathematics
In this paper, we study the regular Sturm–Liouville problems with discontinuous boundary conditions and a weight function which changes sign. We show that the algebraic and geometric multiplicities of the real eigenvalues are the same for some classes of
Zhao Yingchun, Buren Mandula
doaj   +1 more source

Effects of Exogenous Salicylic Acid Application to Aboveground Part on the Defense Responses in Bt (Bacillus thuringiensis) and Non-Bt Corn (Zea mays L.) Seedlings. [PDF]

Plants (Basel), 2022
Feng Y, Wang X, Du T, Shu Y, Tan F, Wang J.   +5 more
europepmc   +1 more source

Environmental Behaviors of Bacillus thuringiensis (Bt) Insecticidal Proteins and Their Effects on Microbial Ecology. [PDF]

Plants (Basel), 2022
Li Y, Wang C, Ge L, Hu C, Wu G, Sun Y, Song L, Wu X, Pan A, Xu Q, Shi J, Liang J, Li P.   +12 more
europepmc   +1 more source

Combinatorial interpretations of the Jacobi-Stirling numbers

, 2009
The Jacobi-Stirling numbers of the first and second kinds were introduced in 2006 in the spectral theory and are polynomial refinements of the Legendre-Stirling numbers.
Gelineau, Yoann, Zeng, Jiang
core   +1 more source