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meteor
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I've noticed what it seems to be an error in Ned Wright's calculator
http://www.astro.ucla.edu/~wright/CosmoCalc.html
First off, I want to present a beautiful theorem that relates 3 of the more often used distances in astronomy. Is called Etherington reciprocity theorem (Etherington,1933). It can be found here
http://arxiv.org/PS_cache/gr-qc/pdf/9910/9910014.pdf
and here
http://nedwww.ipac.caltech.edu/level5/Hogg/Hogg7.html
the theorem is
DL=(1+z)*DS=(1+z)2*DD
DL is luminosity distance
DS is angular size distance
DD is angular diameter distance
If you go to the calculator, and introducing any value of redshift, you don't get the angular size distance, how is indicated, but the angular diameter distance! Just see the value of the luminosity distance and introduce it in Etherington theorem
I'm right in my claims?
http://www.astro.ucla.edu/~wright/CosmoCalc.html
First off, I want to present a beautiful theorem that relates 3 of the more often used distances in astronomy. Is called Etherington reciprocity theorem (Etherington,1933). It can be found here
http://arxiv.org/PS_cache/gr-qc/pdf/9910/9910014.pdf
and here
http://nedwww.ipac.caltech.edu/level5/Hogg/Hogg7.html
the theorem is
DL=(1+z)*DS=(1+z)2*DD
DL is luminosity distance
DS is angular size distance
DD is angular diameter distance
If you go to the calculator, and introducing any value of redshift, you don't get the angular size distance, how is indicated, but the angular diameter distance! Just see the value of the luminosity distance and introduce it in Etherington theorem
I'm right in my claims?
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