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“INFLATION is a period of accelerated expansion (a ̈ > 0) in the early Universe. It was proposed to solve several problems with the Big Bang.” https://lnkd.in/e6ifiQMn View in LinkedIn

“MICROLENSING occurs when the angular separation of images is too small to be resolved (∼ micro arc second) and instead the source is temporarily brightened. Microlensing is a particularly powerful technique for probing compact DM, for instance Primordial Black Holes.” (DM = dark matter), https://lnkd.in/e6ifiQMn View in LinkedIn

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EXEMPLAR. “Galaxy clusters contain 100s or 1000s of galaxies as well as hot X-ray emitting gas. They are the largest gravitationally bound objects in the Universe, therefore we expect that the material they contain is representative of the Universe as a whole.” https://lnkd.in/e6ifiQMn View in LinkedIn

The two spiral arms winding towards the bright centre might deceive you into thinking you are looking at a galaxy a bit like our Milky Way. But the object starring in this image is of a different nature: PK 329-02.2 is a ‘planetary nebula’ within our home galaxy. https://lnkd.in/ehBKkbqy View in LinkedIn

MORE EVIDENCE. “Additional evidence for dark matter comes from the stability of disk galaxies. Self-gravitating disks form bars (‘bar instability’) unless they have large velocity dispersion. Embedding disks in a massive, extended, roughly spherical halo is a solution to this problem.” https://lnkd.in/e6ifiQMn View in LinkedIn

KEY EVIDENCE. “Some of the most straightforward and long standing evidence for DM comes from the rotation curves of spiral galaxies. In a spiral galaxy stars and gas clouds move in circular orbits due to gravity, and their speeds can be measured using the Doppler shift of the Hydrogen 21cm line.” (DM = dark matter). https://lnkd.in/e6ifiQMn View in LinkedIn

OVERVIEW. “In this section we’ll look at the observational evidence for cold, non-baryonic dark matter, starting with galaxies, before moving out in scale to galaxy clusters, the cosmic microwave background anisotropies and large scale structure.” https://lnkd.in/e6ifiQMn View in LinkedIn

STAGE 5. TODAY. The age of the Universe, t0, (i.e. how long after the Big Bang ‘today’ is) is calculated for a ΛCDM universe https://lnkd.in/e6ifiQMn View in LinkedIn

STAGE 4. STRUCTURE FORMATION. “Structures start forming at ∼ 0.1 Gyr, and then Λ, or dark energy, comes to dominate the Universe, causing its expansion to accelerate, at t ∼ 10 Gyr.” https://lnkd.in/e6ifiQMn View in LinkedIn