
Re: Compactifications
Posted:
Mar 23, 2013 10:16 PM


On Sat, 23 Mar 2013, David C. Ullrich wrote: > >> On Sat, 23 Mar 2013 00:30:27 0700, William Elliot <marsh@panix.com> > >> wrote: > >> > >> >Number of nonhomeomophic npoint Hausdorff compactifications > >> Compactifications of _what_? > > The space described at the beginning of each paragraph.
> >The reals x {0,1,...,k} I suppose. > > No, there's only one compactification of that set. There's only one onepoint compactification. There are at least two twopint compactifications:
the disjoint sum of a onepoint compactificaiton of Rx{0} and a onepoint compactification of Rx{1,2,.. k} a onepoint p compactification of Rx{1,2,.. k} with a closed unit interval one end of which is attached to the compactifing point p.
> >>What the heck does that notation mean? > >Too compact, is it?
:}
> I'm going to pretend you didn't say that...

