Green's function for Sturm-Liouville problem

The purpose of this study is to investigate a new class of boundary value transmission problems (BVTP's) for Sturm-Liouville equation on two separate intervals. We introduce modified inner product in direct sum space $L_{2}[a,c)\oplus L_{2}(c,b]\oplus\mathbb{C}^{2}$ and define symmetric linear operator in it such a way that the considered problem can be interpreted as an eigenvalue problem of this operator. Then by suggesting an own approaches we construct Green's function for problem under consideration and find the resolvent function for corresponding inhomogeneous problem

Modified Expansion Theorem for Sturm-Liouville problem with transmission conditions

This paper is devoted to the derivation of expansion a associated with a discontinuous Sturm-Liouville problems defined on $[-\pi, 0)\cup(0,\pi]$. We derive an eigenfunction expansion theorem for the Green's function of the problem as well as a theorem of uniform convergence of a certain class of functions

α\alpha-Parameterized Differential Transform Method

In this paper we propose a new version of differential transform method (we shall call this method as $\alpha$-parameterized differential transform method), which differs from the traditional differential transform method in calculating coefficients of Taylor polynomials. Numerical examples are presented to illustrate the efficiency and reliability of own method. The result reveal that $\alpha$-Parameterized differential transform method is a simple and effective numerical algorithm

Asymptotic formulas for eigenvalues and eigenfunctions of a new boundary-value-transmission problem

In this paper we are concerned with a new class of BVP' s consisting of eigendependent boundary conditions and two supplementary transmission conditions at one interior point. By modifying some techniques of classical Sturm-Liouville theory and suggesting own approaches we find asymptotic formulas for the eigenvalues and eigenfunction

Expansion Theorem for Sturm-Liouville problems transmission conditions

The purpose of this paper is to extend some spectral properties of regular Sturm-Liouville problems to the special type discontinuous boundary-value problem, which consists of a Sturm-Liouville equation together with eigenparameter-dependent boundary conditions and two supplementary transmission conditions. We construct the resolvent operator and Green's function and prove theorems about expansions in terms of eigenfunctions in modified Hilbert space $L_{2}[a, b]$. \vskip0.3cm\noindent Keywords: Boundary-value problems, transmission conditions, Resolvent operator, expansion theorem

Selfadjoint realization of boundary-value problems with interior singularities

The purpose of this paper is to investigate some spectral properties of Sturm-Liouville type problems with interior singularities. Some of the mathematical aspects necessary for developing own technique presented. By applying this technique we construct some special solutions of the homogeneous equation and present a formula and the existence conditions of Green's function. Further based on this results and introducing operator treatment in adequate Hilbert space we derive the resolvent operator and prove selfadjointness of the considered problem

Boundary value problem with transmission conditions

One important innovation here is that for the Sturm-Liouville considered equation together with eigenparameter dependent boundary conditions and two supplementary transmission conditions at one interior point. We develop Green's function method for spectral analysis of the considered problem in modified Hilbert space.Comment: arXiv admin note: substantial text overlap with arXiv:1303.689

Asymptotic formulas for eigenvalues and eigenfunctions of boundary value problem

In this paper we are concerned with a new class of BVP' s consisting of eigendependent boundary conditions and two supplementary transmission conditions at one interior point. By modifying some techniques of classical Sturm-Liouville theory and suggesting own approaches we find asymptotic formulas for the eigenvalues and eigenfunction.Comment: arXiv admin note: substantial text overlap with arXiv:1303.688

Exact Solov'ev equilibrium with an arbitrary boundary

Exact Solov'ev equilibria for arbitrary plasma cross-sections are calculated using a constrained least-squares method. The boundary, with or without $X$-points, can be specified with an arbitrarily large number of constraints to ensure an accurate representation. Thus, the order of the polynomial basis functions in the homogeneous solution of the Grad-Shafranov equation becomes an independent parameter determined only by the accuracy requirements of the overall solution. Examples of exact, highly-shaped equilibria are presented.Comment: 12 pages, 3 figures v2: In Eq. 7 and in the captions for Figs. 2 and 3, the constants A and C have been switche

Role of poloidal-pressure-asymmetry-driven flows in L-H transition and impurity transport during MGI shutdowns

Poloidal asymmetries in tokamaks are usually investigated in the context of various transport processes, usually invoking neoclassical physics. A simpler approach based on magnetohydrodynamics (MHD), focusing on the effects rather than the causes of asymmetries, yields useful insights into the generation of shear flows and radial electric field. The crucial point to recognize is that an MHD equilibrium in which the plasma pressure is not a flux function can be maintained only by contributions from mass flows. Coupling between the asymmetry-generated forces and toroidal geometry results in a strongly up-down asymmetric effect, where the flows exhibit a strong dependence on the location of the asymmetry with respect to the midplane. This location-dependence can be used as an effective control mechanism for the edge and thus the global confinement in tokamaks. It can also explain a number of poorly-understood observations. For instance, strong dependence of the low to high (L-H) confinement transition power threshold $P_{LH}$ on the magnetic topology can be qualitatively explained within this framework. Similarly, upper-lower midplane dependence of the poloidal flow direction after massive gas injections (MGI) naturally follows from this discussion. Similar arguments suggest that the ITER fueling ports above the midplane, to the extent they can generate a positive pressure asymmetry at the edge, are misplaced and may lead to higher input power requirements.Comment: 17 pages, 10 figure