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Reiner Schätzle

Publications and source records attributed to Reiner Schätzle.

6 recordsLinked to original sources

Stability of the free boundary Willmore problem

We study the Willmore problem with free boundary by means of a new Łojasiewicz-Simon gradient inequality for functionals on infinite dimensional manifolds. In contrast to previous works, we do not rely on a gradient-like representation of the Fréchet derivative, but merely on an inequality. For the free boundary Willmore flow, we prove that solutions starting sufficiently close to a local minimizer exist for all times and converge. In the static setting, we prove quantitative stability of free boundary Willmore immersions and a local rigidity result in a neighborhood of free boundary minimal surfaces.

math.AP↗

The Willmore Flow of Tori of Revolution

We study long-time existence and asymptotic behavior for the $L^2$-gradient flow of the Willmore energy, under the condition that the initial datum is a torus of revolution. We show that if an initial datum has Willmore energy below $8π$ then the solution of the Willmore flow converges for $t \rightarrow \infty$ to the Clifford Torus, possibly rescaled and translated. The energy threshold of $8π$ turns out to be optimal for such a convergence result. We give an application to the conformally constrained Willmore minimization problem.

math.AP↗

Semigroups Generated by Elliptic Operators in Non-Divergence Form on $C_0(/omega)$

Given a bounded domain in the Euclidean space satisfying the uniform outer cone condition, we show that a uniformly elliptic operator of second order with continuous second order coefficients generates a holomorphic semigroup on the space of all continuous functions vanishing at the boundary. In particular, Lipschitz domains are allowed. This result was so far known under considerable stronger regularity assumptions. Also the Dirichlet problem is considered for such operators.

math.AP↗

Minimizers of the Willmore functional under fixed conformal class

We consider the problem of minimizing the Willmore energy in the class of conformal immersions of a given closed, genus p Riemann surface into R^n for n=3,4. We prove existence of a smooth minimizer, provided that the infimum is below a certain bound ${\cal W}(n,p)$. For tori in R^3 we have explicitely ${\cal W}(3,1) = 8π$.

math.DG↗

Closed surfaces with bounds on their Willmore energy

The Willmore energy of a closed surface in R^n is the integral of its squared mean curvature, and is invariant uner Möbius transformations of R^n. We show that any torus in R^3 with energy at most $8 π-delta$ has a representative under the Möbius action, for which the induced metric and a conformal metric of constant (zero) curvature are uniformly equivalent, with constants depending only on $delta>0$. An analogous estimate is also obtained for surfaces of fixed genus $p \geq 1$ in R^3 or R^4, assuming suitable energy bounds which are sharp for n=3. Moreover the conformal type is controlled in terms of the energy bounds.

math.DG↗