A Riemann–Hilbert Approach to the Laplace Equation
✍ Scribed by A.S. Fokas; A.A. Kapaev
- Publisher
- Elsevier Science
- Year
- 2000
- Tongue
- English
- Weight
- 207 KB
- Volume
- 251
- Category
- Article
- ISSN
- 0022-247X
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✦ Synopsis
Let q x, y satisfy the Laplace equation in an arbitrary convex polygon. By performing the spectral analysis of the equation y ik s q y iq , z s x q iy, z x y Ž . which involves solving a scalar Riemann᎐Hilbert RH problem, we construct an Ž . integral representation in the complex k-plane of q x, y in terms of a function Ž . Ž . k . It has been recently shown that the function k can be expressed in terms of the given boundary conditions by solving a matrix RH problem. Here we show that this method is also useful for solving problems in a non-convex polygon.
We also recall that for simple polygons it is possible to bypass the above integral representation and to solve the Laplace equation by formulating a RH problem in the complex z-plane.
📜 SIMILAR VOLUMES
## Abstract This paper concerns the existence of nontrivial solutions of the Riemann‐Hilbert problem with a continuous coefficient whose values belong to two rays in the complex plane. Our results extend those recently obtained by E. Shargorodsky and J. F. Toland [6]. (© 2004 WILEY‐VCH Verlag GmbH
harmonic responses. For m s 0.25 and a fortiori for lower values of m, good agreement can be noted between results obtained with the use of the HB technique and the perturbation method. Only a slight difference appears around the resonance frequency. As m increases, HB responses become less smooth.
We derive a semiclassical time evolution kernel and a trace formula for the Dirac equation. The classical trajectories that enter the expressions are determined by the dynamics of relativistic point particles. We carefully investigate the transport of the spin degrees of freedom along the trajectori
where ~( 5 ) is a rational function. ## Bibliography [I] Pogorzelski, W., Integral Equations and their Applications, Pergamon Press, 1966, (see the references [2] Peters, A. S., Pairs o f Cauchy singular integral equations and the kernel [ b ( z ) f a ( { ) ] / ( z -{), at the end of this book).