[Cos-top] half-turn space analysis; new spherical 3-manifolds ?

[sven.lustig at uni-ulm.de]

hi Boud, cos-top,

yes! N8-N10 that are orbifolds.

In arXiv:1201.1875 N8-N10 are also called orbifolds. In this paper one  
finds the orbifold N11.

Best,
Sven


Zitat von Boud Roukema <boud at astro.uni.torun.pl>:

> hi Sven, cos-top,
>
> On Thu, 10 May 2012, sven.lustig uni-ulm.de wrote:
>> Zitat von Boud Roukema <boud astro.uni.torun.pl>:
>
>> In the notation of Peter Kramer N1-N7 are platonic manifolds.
>> In contrast N8-N11 are orbifolds. These orbifolds are generated   
>> from platonic manifolds using their discret rotation symmetry.
>
> Thanks for the correction - I think you are saying that these are
> orbifolds that are not manifolds. Is that right?
>
> From what I understand (e.g. [1] and discussions with Jeff and Vincent),
>   manifold without boundary \Rightarrow orbifold,
> but
>   orbifold \not\Rightarrow manifold.
>
> So that means that the word descriptions of N8-N10 in
> http://arxiv.org/abs/1009.5825 (v1 and published version) are
> incorrect in the sense that these are not 3-manifolds, although they
> are 3-orbifolds.
>
> Also, do you mean N8-N10? I don't see N11 defined in 1009.5285.
>
> cheers
> boud
>
> [1] http://en.wikipedia.org/wiki/Orbifold
>
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