Abstract:
All empirical data relating to our Universe are currently well fit by
a basic model that contains only a few key ingredients: the background
is described by homogeneous and isotropic solutions within General
Relativity, in which there is domination by vacuum energy and cold
dark matter in a roughly flat expanding geometry; the density
fluctuations appear to be nearly scale-invariant, adiabatic and
Gaussian (close to the simplest thing we could imagine); and all of
today’s structure grew through gravitational instability. Within this
picture the Universe is described by just a handful of numbers, which
are now known to quite high precision. So what is left to do in
cosmology? How many digits of precision do we need? Where did these
values come from? Are there more numbers that we haven’t thought of
yet? Is this model anything like the Standard Model of Particle
Physics? Are there signs that we need “physics beyond the standard
model"? Did someone say "anomalies" and "tensions”?
|