Re: Cosmological redshift and Doppler shift

In article <[EMAIL PROTECTED]>,
 <[EMAIL PROTECTED]> wrote:

>Equation (4) is wrong.  Either that, or the authors mean something
>quite different by it than what it seems to mean; I haven't read the
>paper carefully enough yet to know.  

I misinterpreted the notation in this equation, so what I said
is wrong.  Sorry about that.  I shouldn't have posted before
reading the whole paper carefully.

The thing that they're calling v_{pec} is not, as I assumed,
the thing normally defined as the peculiar velocity.  

There's still an inconsistency here: the authors must not be taking
the special-relativistic limit correctly.  The reason I can be so sure
about that is that, as Phillip noted, the inconsistency they point to
occurs even in the Omega = 0, Lambda = 0 FRW spacetime.  But that
spacetime (the Milne spacetime to its friends) is precisely flat
Minkowski spacetime.  So the special relativistic limit, if taken
correctly, must work exactly in that case.

I'm not completely sure what the source of the problem is.  I have a
guess, but I'm not going to risk making a fool of myself yet again by
posting a guess before I'm sure.  I'll work through the paper
carefully before posting about it again.

Again, sorry for the premature and incorrect post.

-Ted

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