tag:blogger.com,1999:blog-14162253.post7429541099319280783..comments2024-03-28T18:57:15.124-06:00Comments on Wash Park Prophet: Lots of Dark Matter Actually Just DimAndrew Oh-Willekehttp://www.blogger.com/profile/02537151821869153861noreply@blogger.comBlogger5125tag:blogger.com,1999:blog-14162253.post-29913620374271117072011-02-28T16:44:57.597-07:002011-02-28T16:44:57.597-07:00Footnote: The standard estimate of regular matter...Footnote: The standard estimate of regular matter and dark matter is 4.6% and 23% respectively. If the amount of regular matter is tripled and the amount of combined dark and regular matter remains the same, this leaves a result of 13.8% regular matter and 13.8% dark matter, a surprising 50-50 correspondence that might fit a scenario in which half of the matter in the universe is ordinary and half of made of invisible SUSY particles, for example.<br /><br />Alternately, it might support a scenario in which half of the mass in the universe comes from quark matter and half comes from lepton matter, with the leptonic portion being comprised predominantly of neutrinos. This result could flow perhaps from the democratic nature of the W particle that does not favor quark over lepton decays given sufficient energy.Andrew Oh-Willekehttps://www.blogger.com/profile/02537151821869153861noreply@blogger.comtag:blogger.com,1999:blog-14162253.post-21990011139994500552010-12-06T15:29:48.623-07:002010-12-06T15:29:48.623-07:00Thanks Karl. You've answered exactly one of m...Thanks Karl. You've answered exactly one of my key questions about this paper.<br /><br />Given its immense implications, and seemingly very solid empirical basis, I'm surprised that it hasn't received more fanfare.Andrew Oh-Willekehttps://www.blogger.com/profile/02537151821869153861noreply@blogger.comtag:blogger.com,1999:blog-14162253.post-39136505352401439632010-12-05T12:01:35.023-07:002010-12-05T12:01:35.023-07:00lots-of-dark-matter-actually-just-dim
Ooh. The Re...lots-of-dark-matter-actually-just-dim<br /><br />Ooh. The Republican Party.Dave Barneshttps://www.blogger.com/profile/07355264650239868491noreply@blogger.comtag:blogger.com,1999:blog-14162253.post-5653937422193150672010-12-03T20:53:29.922-07:002010-12-03T20:53:29.922-07:00I should have said the authors avoid saying it wou...I should have said the authors <i>avoid</i> saying it would mean less dark matter. But that's the implication.Karlhttps://www.blogger.com/profile/00735957696484358430noreply@blogger.comtag:blogger.com,1999:blog-14162253.post-41027012194420925472010-12-03T20:42:19.824-07:002010-12-03T20:42:19.824-07:00Authors do say this would reduce the estimates of ...Authors do say this would reduce the estimates of dark matter. But they hedge it I think because there's enough complications to deal with in proposing an "initial mass function" that describes something that might have happened 10 billion years in the galaxies' past. Last line of the paper: "The bottom-heavy IMF advocated here may also require a relatively low fraction of dark matter within the central regions of nearby massive galaxies"<br /><br />Understatement is an art in physics.<br /><br />The reason the IMF gives a fraction is because in the model the total mass of each galaxy is estimated from gravitational lensing effects (Ref. 22 of the paper.)Karlhttps://www.blogger.com/profile/00735957696484358430noreply@blogger.com