Ultra-compact structure in radio quasars as a cosmological probe: a
  revised study of the interaction between cosmic dark sectors
  A new compilation of $120$ angular-size/redshift data for compact radio
quasars from very-long-baseline interferometry (VLBI) surveys motivates us to
revisit the interaction between dark energy and dark matter with these probes
reaching high redshifts $z\sim 3.0$. In this paper, we investigate
observational constraints on different phenomenological interacting dark energy
(IDE) models with the intermediate-luminosity radio quasars acting as
individual standard rulers, combined with the newest BAO and CMB observation
from Planck results acting as statistical rulers. The results obtained from the
MCMC method and other statistical methods including Figure of Merit and
Information Criteria show that: (1) Compared with the current standard candle
data and standard clock data, the intermediate-luminosity radio quasar standard
rulers , probing much higher redshifts, could provide comparable constraints on
different IDE scenarios. (2) The interaction between dark energy and dark
matter seems to be vanishing or slightly smaller than zero. At the 68.3\%
confidence level, the energy is seen transferred from dark matter to dark
energy, which implies that those IDE models can not alleviate the coincidence
problem or even more sever. However, the strong degeneracies between the
interaction term and Hubble constant may contribute to alleviate the tension of
$H_0$ between the recent Planck and HST measurements. (3) Concerning the
ranking of competing dark energy models, IDE with more free parameters are
substantially penalized by the BIC criterion, which agrees very well with the
previous results derived from other cosmological probes.
