[astroph/0603213] Comments on "Dark matter: A phenomenological existence proof"
Authors:  R. G. Vishwakarma 
Abstract:  A recent paper by AhluwaliaKhalilova (astroph/0601489) is examined where he claims that the standard FRW cosmology with a $\Lambda$ predicts existence of dark matter without invoking the data on galactic rotation curves and gravitational lensing. However, we find that his claims are not correct. He has already assumed (without realizing) in the very outset what he wants to prove. 
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[astroph/0603213] Comments on \"Dark matter: A phenome
In astroph/0601489, within the framework of the Einsteinian general relativity, we made the observation that if the universe is described by a spatially flat FriedmannRobertsonWalker (FRW) cosmology with Einsteinian cosmological constant then the resulting cosmology predicts a significant dark matter component in the universe. Furthermore, the phenomenologically motivated existence proof refrained from invoking the data on galactic rotational curves and gravitational lensing, but used as input the age of the universe as deciphered from the studies on globular clusters. This claim has been challenged in astroph/0603213 by Vishwakarma. The raised objection is invalid. It, at best, constitutes a trivial consistency check. As such, we stand by our analysis, and by our conclusions, without reservations.
The details are to appear soon in astroph/0603256.
The details are to appear soon in astroph/0603256.

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[astroph/0603213] Comments on \"Dark matter: A phenome
Is that predicts or requires?the resulting cosmology predicts a significant dark matter component in the universe
Garth

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Re: [astroph/0603213] Comments on \\\\\\\"Dark matter:
Garth, what happens is that for the present epoch I find a Omega_m which is some 4 to 7 times larger than Omega_baryonic. The deficit, by definition dark matter, is then some nonrelativstic form of matter outside the standard model. Does this answer your question?Garth Antony Barber wrote:Is that predicts or requires?the resulting cosmology predicts a significant dark matter component in the universe
Garth
Dharam

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Re: [astroph/0603213] Comments on \\\\\\\\\\\\\\\"Dark
Yes, but you make the (very reasonable) mainstream model assumption thatD. V. AhluwaliaKhalilova wrote:Garth, what happens is that for the present epoch I find a Omega_m which is some 4 to 7 times larger than Omega_baryonic. The deficit, by definition dark matter, is then some nonrelativstic form of matter outside the standard model. Does this answer your question?Garth Antony Barber wrote:Is that predicts or requires?the resulting cosmology predicts a significant dark matter component in the universe
Garth
Dharam
[tex]Omega_{Total} = 1[/tex],
[tex]\omega \sim 1[/tex] and
[tex]Omega_{baryon} = 0.04[/tex].
A true prediction of the Friedmann models would leave these parameters open.
Garth

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Re: [astroph/0603213] Comments on \\\\\\\\\\\\\\\\\\\\\\\\\
Thanks for the clarification. My result can be interpreted two ways. A [tex]\Omega_m > 0.05[/tex] necessarily requires dark matter; or, as a breakdown of the standard cosmology. Specifically, for [tex]\Lambda = 3 (8 \pi G) 10^{47}\;GeV^4 [/tex] (which gives present cosmic epoch of about [tex]13.5\; Gyr[/tex] for [tex]h=0.72[/tex] )I find [tex]\Omega_m \approx 0.28[/tex]. The standard model contribution of [tex]\Omega_{sm}\approx 0.05[/tex] falls too short. So there is either some unkown nonrelativiistic matter (dark matter, [tex]\Omega_{dm}\approx 0.23[/tex]), or the LCDM fails.Garth Antony Barber wrote:Yes, but you make the (very reasonable) mainstream model assumption thatD. V. AhluwaliaKhalilova wrote:Garth, what happens is that for the present epoch I find a Omega_m which is some 4 to 7 times larger than Omega_baryonic. The deficit, by definition dark matter, is then some nonrelativstic form of matter outside the standard model. Does this answer your question?Garth Antony Barber wrote:Is that predicts or requires?the resulting cosmology predicts a significant dark matter component in the universe
Garth
Dharam
[tex]Omega_{Total} = 1[/tex],
[tex]\omega \sim 1[/tex] and
[tex]Omega_{baryon} = 0.04[/tex].
A true prediction of the Friedmann models would leave these parameters open.
Garth
I hope to write up these details and more under the title 'Dark matter, and its darkness' in a week or so. When done, I plan to archive these on arXiv for comments before a formal submission.
Dharam