Compatibility of the Large Quasar Groups with the Concordance
  Cosmological Model
  We study the compatibility of large quasar groups with the concordance
cosmological model. Large Quasar Groups are very large spatial associations of
quasars in the cosmic web, with sizes of 50-250h^-1 Mpc. In particular, the
largest large quasar group known, named Huge-LQG, has a longest axis of
~860h^-1 Mpc, larger than the scale of homogeneity (~260 Mpc), which has been
noted as a possible violation of the cosmological principle. Using mock
catalogues constructed from the Horizon Run 2 cosmological simulation, we found
that large quasar groups size, quasar member number and mean overdensity
distributions in the mocks agree with observations. The Huge-LQG is found to be
a rare group with a probability of 0.3 per cent of finding a group as large or
larger than the observed, but an extreme value analysis shows that it is an
expected maximum in the sample volume with a probability of 19 per cent of
observing a largest quasar group as large or larger than Huge-LQG. The Huge-LQG
is expected to be the largest structure in a volume at least 5.3 +- 1 times
larger than the one currently studied.
