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“FIGURE 1: Evolution of the log of the density of the universe, ε, with the log of the scale factor, a. The universe starts off radiation dominated (red line), becomes matter dominated (blue) and then at late times is dominated by the cosmological constant (burgundy).” https://lnkd.in/e6ifiQMn View in LinkedIn

DARK MATTER AND DARK ENERGY are the subject of the next section in this blog. This is clearly the elephant in the room of modern astrophysics, since it is so enormous and so unresolved. It is a reminder of how much we are still in the Dark Ages, a backward species. View in LinkedIn

Hubble shot of giant gas and dust clouds that eventually coalesce into stars. https://lnkd.in/eWq3Y_st View in LinkedIn

Hubble shot of Mystic Mountain. https://lnkd.in/eYGpfGVM View in LinkedIn

ALMOST FORGOTTEN. “In the upper reaches of pleasure and on the boundary of fear is a little studied emotion – awe.” https://lnkd.in/ew43YnMu View in LinkedIn

“We live in a universe which is very close to flat, the curvature density is hence small and it never dominates.” https://lnkd.in/e6ifiQMn View in LinkedIn

PHOTONS EXCEED BARYONS. “The present day photon number density is nγ,0 = 4.1×10(8) m(-3), which is roughly nine orders of magnitude greater than the present day baryon number density; the fact that there is a huge number of photons for every baryon has consequences for the thermal history of the Universe.” https://lnkd.in/e6ifiQMn View in LinkedIn

EARLY UNIVERSE. “For significant periods of time the density of the Universe is dominated by a single component. Therefore it’s instructive to initially consider the evolution of simple, single component, flat universes.” https://lnkd.in/e6ifiQMn View in LinkedIn

TWO TYPES. “Finally, we conclude by looking at what astrophysical and cosmological observations can tell us about the nature of dark matter, focusing on two particular cases: warm and self-interacting dark matter.” https://lnkd.in/e6ifiQMn View in LinkedIn

DISTRIBUTION. “To detect dark matter we need to know how it’s distributed, in particular in the Milky Way, so next we overview relevant results from numerical simulations and observations.” https://lnkd.in/e6ifiQMn View in LinkedIn