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Posts by Dan Piker

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Ahlfors circle maps and total reality: from Riemann to Rohlin This is a prejudiced survey on the Ahlfors (extremal) function and the weaker {\it circle maps} (Garabedian-Schiffer's translation of "Kreisabbildung"), i.e. those (branched) maps effecting the confor...

There's also an extended edition arxiv.org/abs/1211.3680

10 months ago 12 3 1 1

I guess the crow took a scenic route

10 months ago 4 0 1 0
Seminar | Illustrating Mathematics

The talk was part of this series illustratingmath.org/node/42 and the recording will appear later on www.youtube.com/@Illustratin...

1 year ago 1 0 0 0
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I enjoyed a presentation from Jason Cantarella yesterday, during which he showed a nice cyclic deformation of the Borromean rings. @henryseg.bsky.social made a comment about whether a similar motion would be possible as a Möbius transformation, which inspired me to create this:

1 year ago 23 3 2 1
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For anyone else curious what each one represents:

1 year ago 3 0 1 0
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This surface can be described as a diagonal on the hypersphere. See thread here for some explanation:
mathstodon.xyz/@Danpiker/11...

1 year ago 6 0 0 0
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Diagonal on a 3-sphere - 3D model by dpiker Diagonal on a 3-sphere - 3D model by dpiker

skfb.ly/puHHF

1 year ago 8 4 1 0
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Hopfodrome - 3D model by dpiker Hopfodrome - 3D model by dpiker

skfb.ly/puwQw

1 year ago 5 0 0 0
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1 year ago 10 1 0 0
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Please help my mug did a topology

1 year ago 119 24 8 4
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Danpiker (@Danpiker@mathstodon.xyz) Attached: 1 image

oof, that compression is grim. Same file on Mastodon for comparison mathstodon.xyz/@Danpiker/11...

1 year ago 1 0 0 0
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A triply orthogonal system of surfaces from stereographic projection of Hopf coordinates

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1 year ago 8 2 0 0

If you select the image icon, it lets you upload in gif format, and the preview shows it animated, but when you post it's just a still. If you select the filmstrip icon you can upload as gif, and it plays when posted (though still as a compressed video not actually gif)

1 year ago 0 0 1 0
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Here's the same uploaded as mp4 at 30fps

1 year ago 0 0 1 0

nope, still stutters in the app. Plays smoothly on mobile browser though.

1 year ago 0 0 0 0
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Trying at 30fps

1 year ago 4 0 2 0

Testing out the new gif upload option here.
It appears they still actually get converted to mp4, but with different compression to if you upload as mp4 (twitter was similar). This was uploaded as a 50fps gif. It loops smoothly when viewed on desktop, but stutters on the android app :(

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