Clustering of intermediate redshift quasars using the final SDSS
  III-BOSS sample
  We measure the two-point clustering of spectroscopically confirmed quasars
from the final sample of the Baryon Oscillation Spectroscopic Survey (BOSS) on
comoving scales of 4 < s < 22 Mpc/h. The sample covers 6950 deg^2 (~ 19
(Gpc/h)^3) and, over the redshift range 2.2 < z < 2.8, contains 55,826
homogeneously selected quasars, which is twice as many as in any similar work.
We deduce b_Q = 3.54 +/- 0.10 ; the most precise measurement of quasar bias to
date at these redshifts. This corresponds to a host halo mass of ~ 2 x 10^12 ~
M_sun/h with an implied quasar duty cycle of ~1 percent. The real-space
projected correlation function is well-fit by a power law of index -2 and
correlation length r0 = (8.12 +/- 0.22), Mpc/h over scales of 4 < rp < 25 ~
Mpc/h. To better study the evolution of quasar clustering at moderate redshift,
we extend the redshift range of our study to z ~ 3.4 and measure the bias and
correlation length of three subsamples over 2.2 < z < 3.4. We find no
significant evolution of r0 or bias over this range, implying that the host
halo mass of quasars decreases somewhat with increasing redshift. We find
quasar clustering remains similar over a decade in luminosity, contradicting a
scenario in which quasar luminosity is monotonically related to halo mass at z
~ 2.5. Our results are broadly consistent with previous BOSS measurements, but
they yield more precise constraints based upon a larger and more uniform data
set.
