View Full Version : Relativistic red shift

doc33

2009-Dec-09, 08:40 PM

I am trying to find a formula to calculate the look back distance to an object with v>c. Any of the relativistic formulae I have seen all have the 1-v/c term in the denominator.

Does the Hubble formula for d, cz = H[sub 0]d, work for high values for z ?

[ z>1]

Help please.

slang

2009-Dec-09, 08:48 PM

Does this thread help?

Redshifts greater than C (http://www.bautforum.com/space-astronomy-questions-answers/97536-redshifts-greater-than-c.html)

ngc3314

2009-Dec-09, 09:22 PM

For large values, you will want to work with redshift z itself rather than trying to convert to v/c (not least because of the nontrivial meaning of distance measures in an expanding Universe). One place to get specific values is Ned Wright's Cosmology Calculator (http://www.astro.ucla.edu/~wright/CosmoCalc.html).

doc33

2009-Dec-10, 02:38 AM

I am trying to find a way to calculate the look back distance to an object with v>c. Most of the equations that address relativistic red shift contain

1 -[v/c] squared in the denominator and are only valid for v<c.

Can anyone help ?

doc33

2009-Dec-10, 03:04 AM

Thanks for the help. The Davis Lineweaver paper has what I was after.

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