Wednesday, March 27, 2024

Cold Dark Matter Fails Again

Once again, the observed dynamics of galaxies are inconsistent with cold dark matter halos. There are dozens of other completely independent instances of empirical evidence contradicting the LambdaCDM Standard Model of Cosmology. I have faith that eventually this reality will sink into the community of astrophysicists and cosmologists, but I have no idea how long it will take to get there.
Simulations of structure formation in the standard cold dark matter cosmological model quantify the dark matter halos of galaxies. Taking into account dynamical friction between the dark matter halos, we investigate the past orbital dynamical evolution of the Magellanic Clouds in the presence of the Galaxy. 
Our calculations are based on a three-body model of rigid Navarro-Frenk-White profiles for the dark matter halos, but were verified in a previous publication by comparison to high-resolution N-body simulations of live self-consistent systems. Under the requirement that the LMC and SMC had an encounter within 20 kpc between 1 and 4 Gyr ago, in order to allow the development of the Magellanic Stream, and using the latest astrometric data, the dynamical evolution of the MW/LMC/SMC system is calculated backwards in time. 
With the employment of the genetic algorithm and a Markov-Chain Monte-Carlo method, the present state of this system is unlikely with a probability of <10^-9 (6 sigma complement), because solutions found do not fit into the error bars for the observed plane-of-sky velocity components of the Magellanic Clouds. This implies that orbital solutions that assume dark matter halos according to cosmological structure formation theory to exist around the Magellanic Clouds and the Milky Way are not possible with a confidence of more than 6 sigma.
Wolfgang Oehm and Pavel Kroupa, "The Relevance of Dynamical Friction for the MW/LMC/SMC Triple System" 10 Universe 143 arXiv:2403.17999 (March 26, 2024).

Tuesday, March 19, 2024

Not Posting Much

I guess I haven't been posting much this month. I'll get back to it when I have the energy, but quite a long time after testing COVID negative, I'm still really, really tired most of the time. Posts here take more thought and energy than posts at its sister blog or quick shares with a little quip or two on Facebook. 

I'm trying to scan for new notable scientific journal articles and bookmark them as they come out, for future reference, with the little energy that I have.

Wednesday, March 6, 2024

Dark Matter Is Not Made Up Of Primordial Black Holes

We find that compact objects in the mass range from 1.8×10^−4M⊙ to 6.3M⊙ cannot compose more than 1% of dark matter, and compact objects in the mass range from 1.3×10^−5M⊙ to 860M⊙ cannot make up more than 10% of dark matter. This conclusively rules out primordial black hole mergers as a dominant source of gravitational waves.
From: Confirmed from the same data at