A biharmonic Green function of a circular ring domain $R=\{z\in \mathsf {C}: 0<r<|z|<1\}$ is found in the form 26741 \widehat{G}_{2}(z,\zeta)=|\zeta-z|^{2}G_{1}(z,\zeta)+\widehat{h}_{2}(z,\zeta), 26741 where $G_{1}(z,\zeta)$ is the harmonic Green function of the ring $R$, and $\widehat{h}_{2}(z,\zeta)$ is a specially constructed biharmonic function.
AbstractWe develop an accurate approximation of the normalized hyperbolic
operator sine family generated by a strongly positive operator
A in a Banach space X which represents the solution operator for the elliptic boundary
value problem. The solution of the corresponding inhomogeneous boundary value problem is found
through the solution operator and the Green function. Starting with the Dunford —
Cauchy representation for the normalized hyperbolic operator sine family and for the
Green function, we then discretize the integrals involved by the exponentially convergent
Sinc quadratures involving a short sum of resolvents of A. Our algorithm inherits
a two-level parallelism with respect to both the computation of resolvents and the
treatment of different values of the spatial variable x ∈ [0, 1].
We are concerned with the following nonlinear three-point fractional boundary value problem:D0+αut+λatft,ut=0,0<t<1,u0=0, andu1=βuη, where1<α≤2,0<β<1,0<η<1,D0+αis the standard Riemann-Liouville fractional derivative,at>0is continuous for0≤t≤1, andf≥0is continuous on0,1×0,∞. By using Krasnoesel'skii's fixed-point theorem and the corresponding Green function, we obtain some results for the existence of positive solutions. At the end of this paper, we give an example to illustrate our main results.
AbstractThere are three basic boundary value problems for the inhomogeneous polyanalytic equation in planar domains, the well-posed iterated Schwarz problem, and further two over-determined iterated problems of Dirichlet and Neumann type. These problems are investigated in planar domains having a harmonic Green function. For the Schwarz problem, treated earlier [Ü. Aksoy, H. Begehr, A.O. Çelebi, AV Bitsadze’s observation on bianalytic functions and the Schwarz problem. Complex Var Elliptic Equ 64(8): 1257–1274 (2019)], just a modification is mentioned. While the Dirichlet problem is completely discussed for arbitrary order, the Neumann problem is just handled for order up to three. But a generalization to arbitrary order is likely.
Biharmonic Green function of a ring domain
