Density estimates for minimal surfaces and surfaces flowing by mean curvature

Author(s):  
Robert Gulliver
2019 ◽  
Vol 485 (4) ◽  
pp. 410-414
Author(s):  
M. B. Karmanova

For graph mappings constructed from contact mappings of arbitrary two-step Carnot groups, conditions for the correct formulation of minimal surfaces’ problem are found. A suitable notion of the (sub-Riemannian) area functional increment is introduced, differentiability of this functional is proved, and necessary minimality conditions are deduced. They are also expressed in terms of sub-Riemaninan mean curvature.  


Author(s):  
Weihuan Chen ◽  
Yi Fang

AbstractA minimal surface is a surface with vanishing mean curvature. In this paper we study self θ -congruent minimal surfaces, that is, surfaces which are congruent to their θ-associates under rigid motions in R3 for 0 ≤ θ < 2π. We give necessary and sufficient conditions in terms of its Weierstrass pair for a surface to be self θ-congruent. We also construct some examples and give an application.


2003 ◽  
Vol 2003 (21) ◽  
pp. 1323-1330
Author(s):  
Richard H. Escobales

Let(M,g)be a closed, connected, orientedC∞Riemannian 3-manifold with tangentially oriented flowF. Suppose thatFadmits a basic transverse volume formμand mean curvature one-formκwhich is horizontally closed. Let{X,Y}be any pair of basic vector fields, soμ(X,Y)=1. Suppose further that the globally defined vector𝒱[X,Y]tangent to the flow satisfies[Z.𝒱[X,Y]]=fZ𝒱[X,Y]for any basic vector fieldZand for some functionfZdepending onZ. Then,𝒱[X,Y]is either always zero andH, the distribution orthogonal to the flow inT(M), is integrable with minimal leaves, or𝒱[X,Y]never vanishes andHis a contact structure. If additionally,Mhas a finite-fundamental group, then𝒱[X,Y]never vanishes onM, by the above together with a theorem of Sullivan (1979). In this caseHis always a contact structure. We conclude with some simple examples.


2009 ◽  
Vol 40 (4) ◽  
pp. 313-341 ◽  
Author(s):  
Bang-Yen Chen

The concept of trapped surfaces introduced by Sir Roger Penrose in [Phys. Rev. Lett. 14 (1965), 57-59] plays an extremely important role in cosmology and general relativity. A black hole is a trapped region in a space-time enclosed by a marginally trapped surface. In term of mean curvature vector, a space-like surface in a space-time is marginally trapped if its mean curvature vector field is light-like at each point. In this article, we survey recent classification results on marginally trapped surfaces from differential geometric viewpoint. Also, we survey recent results on a closely related subject; namely, quasi-minimal surfaces in pseudo-Riemannian manifolds.


2004 ◽  
Vol 94 (1) ◽  
pp. 109 ◽  
Author(s):  
Anthony Small

There exists a natural correspondence between null curves in $\mathbf{C}^4$ and "free" curves on $\mathcal O(1)\oplus \mathcal O(1)$; it underlies the existence of "Weierstrass type formulae" for minimal surfaces in $\mathbf{R}^4$. The construction determines correspondences for minimal surfaces in $\mathbf{R}^3$, and constant mean curvature 1 surfaces in $\mathrm{H}^3$; moreover it facilitates the study of symmetric minimal surfaces in $\mathbf{R}^4$.


Sign in / Sign up

Export Citation Format

Share Document