A Direct
Emperical Proof of the Existence of Dark Matter
Since Zwicky (1933), we
have known that clusters of galaxies have gravitational potentials which are
too large to be explained by the amount of visible baryons under the assumption
of a Newtonian gravitational force law. This has led to competing
theories that either the masses of clusters are dominated by a non-baryonic
form of matter or that gravity departs from a 1/r^2 force law on cluster
scales. By using merging clusters of galaxies, I will show that the
different types of matter in the clusters can be spatially separated and by
using gravitational lensing I will prove, independent of any assumptions about
the nature of the law of gravity, that the dominant mass component of the
clusters is not the visible baryons. I will also discuss how these
observations can be used to place constraints on the nature of the dark matter,
including a limitation on the self-interaction cross- section of any dark
matter particles, as well as constraints on the gravitational force law.