File:Immersed-Moebius-4.png

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Immersed-Moebius-4.png(470 × 420 pixels, file size: 54 KB, MIME type: image/png)

Captions

Captions

Möbius Strip immersed in 3-Space, truncated Boy's Surface. Edge-on view.

Summary[edit]

Description
English: The image shows a rendering of an immersion of a Möbius strip in 3-dimensional space with the following properies:
  • The only singularities are self-intersections. In particular, the surface has no pinch-points.
  • The surface has 3-fold rotational symmetry, and it has a 2-fold symmetry when flipping it: The surface looks the same when viewed from above or from below. The symmetry group is that of an equilateral triangle, namely the dihedral group of order 6.
  • The locus of self-intersections has the form of the border of a 3-leaved clover with the triple point in the center.
  • The surface is Boy's surface in Bryant-Kusner-parametrization with the top dome removed and adjusted in such a way that it attains the symmetries mentioned above.
  • Conversely, poking a hole into a sphere and gluing this version of the Möbius strip into the hole results in the immersion of the real projective plane in 3-space. The gluing can be performed in such a way that no new self-intersections are needed.

For a complex number w let

and let

Then:

  • With and : x, y, and z are the Cartesian coordinates of a point on Boy's surface in Bryant-Kusner parametrization, which is an immersion of the real projective plane in 3-space. results in an upside-down version of Boy's surface.
  • With and : x, y, and z are the Cartesian coordinates of the shown object. The extra condition "pokes" a hole in the surface and stretches the hole open, leading to the additional flip-symmetry.
Deutsch: Das Bild zeigt die Immersion eines Möbiusbands in den 3-dimensionalen Raum mit folgenden Eigenschaften:
  • Abgesehen von Selbstdurchdringungen hat die dargestellte Fläche keine weiteren Singularitäten, insbesondere hat sie keine Knicke oder Spitzen o.ä.
  • Die Fläche hat 3-fache Rotationssymmetrie, und von oben betrachtet sieht sie genauso aus wie von unten: Die Symmetriegruppe der Fläche ist die gleiche wie die eines gleichseitigen Dreiecks, nämlich die Diedergruppe der Ordnung 6.
  • Die Punkte, die zur Selbstdurchgrungung gehören, haben die Gestalt des Randes eines 3-blättrigen Kleeblatts mit dem Tripelpunkt in der Mitte.
  • Die Fläche ergibt sich aus der Boy'schen Fläche in Bryant-Kusner-Parametrisierung indem man die "obere" Kuppel entfernt und die Fläche so modifiziert, dass sie die o.g. Symmetrien erhält.
  • Umgekehrt erhält man eine Immersion der reellen projektiven Ebene, indem man den Rand einer Kreissscheibe mit dem Rand des Möbiusbandes identifiziert bzw. "verklebt". Die Verklebung ist möglich ohne weitere Selbstdurchdringung(en) zu erzeugen.
Date
Source Own work
Author Georg-Johann
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Date/TimeThumbnailDimensionsUserComment
current17:18, 25 August 2021Thumbnail for version as of 17:18, 25 August 2021470 × 420 (54 KB)Georg-Johann (talk | contribs)Uploaded own work with UploadWizard

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