J. Bevan | Searcharxiv

arXiv2014

A remark on a stability criterion for the radial cavitating map in nonlinear elasticity

An integral functional $I(w) = \int_{B} \left|\adj \nabla w \frac{w}{|w|^{3}}\right|^{q}$ defined on suitable maps $w$ is studied. The inequality $I(w) \geq I(\mathbf{id})$, where $\mathbf{id}$ is the identity map, is established on a subclass of the admissible maps, and as such confirms in these cases a criterion for the local minimality of the radial cavitating map in 3 dimensional nonlinear elasticity. The criterion was first identified by J. Sivaloganathan and S. Spector in, "Necessary conditions for a minimum at a radial cavitating singularity in nonlinear elasticity. Ann. I. H. Poincare 25 (2008) no.1, 201-213".

math.AP↗

arXiv2014

Explicit examples of Lipschitz, one-homogeneous solutions of log-singular planar elliptic systems

We give examples of systems of Partial Differential Equations that admit non-trivial, Lipschitz and one-homogeneous solutions in the form $u(R,θ) = Rg(θ)$, where $(R,θ)$ are plane polar coordinates and $g: \mathbb{R}^{2} \to \mathbb{R}^{m}$, $m \geq 2$. The systems are singular in the sense that they arise as the Euler-Lagrange equations of the functionals $I(u) = \int_{B}W(x,\nabla u(x))\,dx$, where $D_{F}W(x,F)$ behaves like $\frac{1}{|x|}$ as $|x| \to 0$ and $W$ satisfies an ellipticity condition. Such solutions cannot exist when $|x|D_{F}W(x,F) \to 0$ as $|x| \to 0$, so the condition is optimal. The associated analysis exploits the well-known Fefferman-Stein duality. We also discuss conditions for the uniqueness of these one-homogeneous solutions and demonstrate that they are minimizers of certain variational functionals.

math.AP↗