Immersed surface with circle as a boundary - MathOverflow most recent 30 from http://mathoverflow.net2013-05-23T21:27:29Zhttp://mathoverflow.net/feeds/question/118405http://www.creativecommons.org/licenses/by-nc/2.5/rdfhttp://mathoverflow.net/questions/118405/immersed-surface-with-circle-as-a-boundaryImmersed surface with circle as a boundaryMario2013-01-08T23:25:22Z2013-01-09T01:00:31Z
<p>Is there a solution or progress of the following problem (maybe old conjecture): Is An immersed surface with constant mean curvature and with a circle as a boundary part of a sphere??. If we replace "immersed" by "embedded" I think the problem was solved by Alexandroff kind of long time ago. Is someone could enlighten about what exactly Alexandroff solves and what is to do, it would help me a lot.</p>
<p>Thanks
Mario</p>
http://mathoverflow.net/questions/118405/immersed-surface-with-circle-as-a-boundary/118412#118412Answer by Igor Rivin for Immersed surface with circle as a boundaryIgor Rivin2013-01-09T00:57:15Z2013-01-09T00:57:15Z<p>Check out <a href="http://www.ugr.es/~rcamino/publications/pdf/art14.pdf" rel="nofollow">this paper of Rafael Lopez</a> and references therein.</p>
http://mathoverflow.net/questions/118405/immersed-surface-with-circle-as-a-boundary/118413#118413Answer by Gjergji Zaimi for Immersed surface with circle as a boundaryGjergji Zaimi2013-01-09T01:00:31Z2013-01-09T01:00:31Z<p>Assuming your interest is in constant mean curvature surfaces with circular boundary, I found the survey, <a href="http://www.ugr.es/~rcamino/publications/pdf/art57.pdf" rel="nofollow">"Surfaces with constant mean curvature in Euclidean space"</a> by R. Lopez to be a great introduction, and it contains the state of the art, and several references. </p>
<p>Hopf proved that the only constant mean curvature closed surfaces of genus 0 are spheres. Alexandrov's theorem says that constant mean curvature closed surfaces that are embedded are spheres. Unfortunately when we allow boundaries both analogs are conjectural:</p>
<blockquote>
<p><strong>Conjecture 1:</strong> The only constant mean curvature compact surfaces with circular boundary that are topological disks are spherical caps.</p>
<p><strong>Conjecture 2:</strong> The only constant mean curvature compact surfaces with circular boundary that are embedded are spherical caps.</p>
</blockquote>