If I is a (two-sided) ideal of ring R, we let $${\text {ann}}_l(I)=\{r\in R\mid rI=0\},$$ {ann}}_r(I)=\{r\in Ir=0\},$$ and {ann}}(I)={\text {ann}}_l(I)\cap {\text {ann}}_r(I)$$ be the left, right double annihilators. An said to an annihilator if $$I={\text {ann}}(J)$$ for some J (equivalently, {ann}}({\text {ann}}(I))=I$$ ). We study ideals Leavitt path algebras graph $$C^*$$ -algebras. Let $$L...

A. In this paper, by applying the first variation formula of f -bi-energy given in [OND], we study f -biharmonic maps between doubly warped product manifolds M ×(μ,λ) N. Under imposing existence condition concerning proper f -biharmonic maps, we derive f -biharmonicity’s characteristic equations for the inclusion maps: iy0 : (M, g) → (M ×(μ,λ) N, ḡ), ix0 : (N, h) → (M ×(μ,λ) N, ḡ) and th...

In this study, a high accuracy numerical method based on the spectral theory of compact operator for biharmonic eigenvalue equations on a spherical domain is developed. By employing the orthogonal spherical polynomials approximation and the spectral theory of compact operator, the error estimates of approximate eigenvalues and eigenfunctions are provided. By adopting orthogonal spherical base f...

We present a new method of surface generation from prescribed boundaries based on the elliptic partial differential operators. In particular, we focus on the study of the so-called harmonic and biharmonic Bézier surfaces. The main result we report here is that any biharmonic Bézier surface is fully determined by the boundary control points. We compare the new method, by way of practical example...

In this work, we compare different mesh moving techniques for monolithically-coupled fluid-structure interactions in arbitrary Lagrangian–Eulerian coordinates. The mesh movement is realized by solving an additional partial differential equation of harmonic, linear-elastic, or biharmonic type. We examine an implementation of time discretization that is designed with finite differences. Spatial d...

We construct new explicit proper biharmonic functions on the 3-dimensional Thurston geometries Sol, Nil, S̃L2(R), H 2 × R and

In this paper we give an enclosure for the solution of the biharmonic problem and also for its gradient and Laplacian in the L2-norm, respectively.