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hadsed
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I was reading a recent paper on arXiv.org on a novel simulation of MOND, and surprisingly they addressed the Bullet Cluster, which I guess is one of the more serious problems for MOND. What was even more surprising was that they said this posed a problem for Lamda-CDM models as well. Here is the quote:
Page 3, third to last paragraph in this paper: http://arxiv.org/PS_cache/arxiv/pdf/1102/1102.3913v1.pdf
Can someone explain what exactly the problem is? I was under the assumption that the Bullet Cluster was explained pretty well by dark matter.
Perhaps the most prominent example of a cluster with a serious residual discrepancy in MOND is the bullet cluster [29]. In this system, the gravitational lensing of background galaxies indicates that the mass is offset from the X-ray plasma. This is the same residual mass discrepancy that is seen in all rich clusters. While the bullet cluster is frequently cited as evidence against MOND, it is also problematic for ΛCDM. The sub-clusters that compose the bullet cluster collided at a remarkably high velocity (∼ 4700 km s−1). This is exceedingly unlikely in ΛCDM, occurring with a probability of only a few parts in a billion [30]. In contrast, such high collision velocities are natural to MOND [31]. Taken at face value, the bullet cluster would seem to simultaneously support and falsify both theories with equal vigo
Page 3, third to last paragraph in this paper: http://arxiv.org/PS_cache/arxiv/pdf/1102/1102.3913v1.pdf
Can someone explain what exactly the problem is? I was under the assumption that the Bullet Cluster was explained pretty well by dark matter.
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