Talk:Hanner polytope

Latest comment: 1 year ago by David Eppstein in topic f-vector sums

Examples

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I reworked example cases for 4 and 5 dimensions, and David reverted, so I pasted my removed contents below. I don't care to argue with him. This is true, accurate and helpful information, with Klitzing page as a source, notationally all easy to dimensionally verify the products and sums. The main open question for 5D is names and notations used, duoprism and duopyramid. I picked the simplest names and notations I knew. If someone had better sources, feel free! Obviously they're all well known since they're counted to 10-dimensions Hanner_polytope#Combinatorial_enumeration. Tom Ruen (talk) 02:40, 17 November 2022 (UTC)Reply

In higher dimensions the hypercubes and cross polytopes, analogues of the cube and octahedron, are again Hanner polytopes. However, more are possible.{{citation|url=https://bendwavy.org/klitzing/explain/hanner.htm|title=Hanner polytopes|work=Polytopes|first=Richard|last=Klitzing|access-date=2022-11-16}}

In four-dimensions, there are four cases as dual pairs:

In five-dimensions there are eight cases as dual pairs:

  • 5-cube, {4,3,3,3}, and 5-orthoplex, {3,3,3,4},
  • tesseractic bipyramid, {4,3,3}+{ } and 16-cell prism, {3,3,4}×{ },
  • cubic bipyramidal prism, ({4,3}+{ })×{ }, and octahedral prismatic bipyramid, ({3,4}×{ })+{ },
  • square-octahedral duoprism, {4}×{3,4}, and square-cubic duopyramid, {4}+{4,3}.

This paper lists on p.190 4 cases 4D and p.196 lists 4 5D cases and 9 6D cases, ignoring duals. Tom Ruen (talk) 04:30, 17 November 2022 (UTC)Reply

Name key:

Cn=n-cube, CΔ
n
=dual polytope=n-orthoplex
bip P := P ⊕ [−1, 1] denotes a bipyramid, and prism P refers to the prism construction
1D
# Name Translations f-vector
f0
1 C1=CΔ
1
line segment { } 2
2D
# Name Translations f-vector
f0 f1
1 C2=CΔ
2
square {4} = { }×{ } = { }+{ } 4 4
3D
# Name Translations f-vector
f0 f1 f2
1 CΔ
3
octahedron {3,4} 6 12 8
2 C3 cube {4,3} 8 12 6
4D (duals grouped)
# Name Translation
(Dual)
Vertices
(Dual vertices)
f-vector
f0 f1 f2 f3
1
2
CΔ
4

C4
16-cell
(4-cube)
{3,3,4}
{4,3,3}
8
(16)
8 24 32 16
3
4
bip C3
prism CΔ
3
cubic bipyramid
(octahedral prism)
{4,3}+{ }
{3,4}×{ }
8+2
(6×2)
10 28 30 12
5D (duals grouped)
# Name Translation
(Dual)
Vertices
(Dual vertices)
f-vector
f0 f1 f2 f3 f4
1
2
CΔ
5

C5
5-orthoplex
(5-cube)
{3,3,3,4}
{4,3,3,3}
10
(32)
10 40 80 80 32
3
4
bip bip C3
prism prism CΔ
3
cubic-square duopyramid
(octahedron-square duoprism)
{4,3}+{4}
{3,4}×{4}
8+4
(6×4)
12 48 86 72 24
5
6
bip prism CΔ
3

prism bip C3
octahedral prismatic bipyramid
(cubic bipyramidal prism)
({3,4}×{ })+{ }
({4,3}+{ })×{ }
6×2+2
(8+2)×2
14 54 88 66 20
7
8
prism CΔ
4

bip C4
16-cell prism
(tesseractic bipyramid)
{3,3,4}×{ }
{4,3,3}+{ }
8×2
(16+2)
16 56 88 64 18
6D (duals grouped)
# Name Translations
(dual)
Vertices
(Dual vertices)
f-vector
f0 f1 f2 f3 f4 f5
1
2
CΔ
6

C6
6-orthoplex
(6-cube)
{3,3,3,3,4}
{4,3,3,3,3}
12
(64)
12 60 160 240 192 64
3
4
bip bip bip C3
prism prism prism CΔ
3
octahedral-cubic duopyramid
(octahedral-cubic duoprism)
{3,4}+{4,3}
{3,4}×{4,3}
6+8
(6×8)
14 72 182 244 168 48
5
6
C3 ⊕ C3
CΔ
3
× CΔ
3
cubic-cubic duopyramid
(octahedral-octahedral duoprism)
{4,3}+{4,3}
{3,4}×{3,4}
8+8
(6×6)
16 88 204 240 144 36
7
8
bip bip prism CΔ
3

prism prism bip C3
(octahedral prismatic)-square duopyramid
((cubic bipyramidal)-square duoprism)
{3,4}×{ }+{4}
({4,3}+{ })×{4}
6×2+4
(8+2)×4
16 82 196 242 152 40
9
10
bip prism CΔ
4

prism bip C4
16-cell prismatic bipyramid
(tesseractic bipyramidal prism)
{3,3,4}×{ }+{ }
({4,3,3}+{ })×{ }
8×2+2
(16+2)×2
18 88 200 240 146 36
11
12
bip bip C4
prism prism CΔ
4
tesseractic-square duopyramid
(16-cell-square duoprism)
{4,3,3}+{4}
{3,3,4}×{4}
16+4
(8×4)
20 100 216 232 128 32
13
14
prism CΔ
5

bip C5
5-orthoplex prism
(5-cubic bipyramid)
{3,3,3,4}×{ }
{4,3,3,3}+{ }
10×2
(32+2)
20 90 200 240 144 34
15
16
bip prism bip C3
prism bip prism CΔ
3
cubic bipyramidal prismatic bipyramid
(octahedral prismatic bipyramidal prism)
({4,3}+{ })×{ }+{ }
({3,4}×{ }+{ })×{ }
(8+2)×2+2
(6×2+2)×2
22 106 220 230 122 28
17
18
prism bip bip C3
bip prism prism CΔ
3
cubic-square duopyramidal prism
(octahedral-square duoprismatic bipyramid)
({4,3}+{4})×{ }
{3,4}×{4}+{ }
(8+4)×2
6×4+2
24 108 220 230 120 26
This sort of piling on of example farm after example farm, with no published sources for any of the calculations or notations within them, and instead only the vaguest hint that because the total number of examples matches up with OEIS then maybe it is calculated without mistakes, is exactly why I reverted the first edit. Please note that per Wikipedia:Talk page guidelines, talk pages should only be for discussion of how to improve the article according to Wikipedia's standards (which include providing sources for all material); they are not an alternative venue for publishing original research. —David Eppstein (talk) 22:12, 17 November 2022 (UTC)Reply

You ask for a published source, and I provide one, which also listed the 18 6D cases, so I gave them too. You can complain about notations, but there's no reason an encyclopedia can't add varied notations, including notations used elsewhere on wikipedia. The operations are simple, products and sum, already explained in this article. You can perhaps find a dozen different papers listing this, and each might have a slightly different naming scheme. Which should be used? All is fine with me if you think it adds readability. Tom Ruen (talk) 23:06, 17 November 2022 (UTC)Reply

[On Kalai’s conjectures concerning centrally symmetric polytopes
Raman Sanyal Axel Werner Gunter M. Ziegler
Discrete Comput Geom (2009) 41: 183–198
DOI 10.1007/s00454-008-9104-8
That source has some tables with some examples, but not all of them and not all of the information you include about them. To pick a random example among many of a piece of information that is claimed in your tables and appears to exist nowhere in the scientific literature (the first example I tried): there are zero hits in Google Scholar for the phrase "cubic bipyramidal prismatic bipyramid". Where is this terminology sourced from? Are you even trying to base your content on sources or are you just making shit up and then finding sources that sort of match something vaguely related only when pressed? And maybe a bigger question should be: in what way do you think overwhelming an article with huge tables of unfamiliar notation is likely to improve the experience of any readers of the article? —David Eppstein (talk) 23:46, 17 November 2022 (UTC)Reply
That case is EXACTLY the same as bip prism bip C3 written more in english rather than abbreviated prefix notation from the paper table, which happens to only exist in that one paper. Say bip C3 or say cubical bipyramid, take your pick. Tom Ruen (talk) 23:56, 17 November 2022 (UTC)Reply
It is the same polytope but it is far from the same data about the polytope. The name you give it, the curly-bracket notation you give it, the expanded formula for its number of vertices, and the correspondence with its dual are all nowhere to be found in that source. —David Eppstein (talk) 01:26, 18 November 2022 (UTC)Reply

f-vector sums

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Has anyone noticed the f-vector sums are constant by rank? This matches easy case of hypercube face count sums: 2D (4+4)=8, 3D (8+12+6)=26, 4D (16+32+24+8)=80, 5D (32+80+80+40+10)=242, 6D (64+192+240+160+60+12)=728, …? Does anyone know why? — Preceding unsigned comment added by 2601:447:CE00:3C0:C18C:47C2:9C07:F571 (talk) 15:52, 6 June 2023 (UTC)Reply

P.s. The series 8, 26, 80, 242, 728… is simply 3n-1 ! oeis.org — Preceding unsigned comment added by 2601:447:CE00:3C0:94DA:2BC0:96:2A53 (talk) 17:20, 8 June 2023 (UTC)Reply

Consider a hypercube of 3n little cubes. Exactly one of them is hidden. —Tamfang (talk) 22:23, 8 July 2023 (UTC)Reply
This is in our article already under Hanner polytope § Number of faces. See also Kalai's 3d conjecture. Another easy way to see that a hypercube, specifically, has   faces (including the cube itself, but not the empty set, as a face) is to put the faces in bijection with the length-  strings over the alphabet   where a   or   in position   indicates that we are looking at the subset of the cube whose  th coordinate has that value and a   indicates that we are not restricting the  th coordinate. —David Eppstein (talk) 00:07, 9 July 2023 (UTC)Reply