Variable star classification across the Galactic bulge and disc with the
  VISTA Variables in the V\'ia L\'actea survey
  We present VIVACE, the VIrac VAriable Classification Ensemble, a catalogue of
variable stars extracted from an automated classification pipeline for the
Vista Variables in the V\'ia L\'actea (VVV) infrared survey of the Galactic
bar/bulge and southern disc. Our procedure utilises a two-stage hierarchical
classifier to first isolate likely variable sources using simple variability
summary statistics and training sets of non-variable sources from the Gaia
early third data release, and then classify candidate variables using more
detailed light curve statistics and training labels primarily from OGLE and
VSX. The methodology is applied to point-spread-function photometry for
$\sim490$ million light curves from the VIRAC v2 astrometric and photometric
catalogue resulting in a catalogue of $\sim1.4$ million likely variable stars,
of which $\sim39,000$ are high-confidence (classification probability $>0.9$)
RR Lyrae ab stars, $\sim8000$ RR Lyrae c/d stars, $\sim187,000$
detached/semi-detached eclipsing binaries, $\sim18,000$ contact eclipsing
binaries, $\sim1400$ classical Cepheid variables and $\sim2200$ Type II Cepheid
variables. Comparison with OGLE-4 suggests a completeness of around $90\,\%$
for RRab and $\lesssim60\%$ for RRc/d, and a misclassification rate for known
RR Lyrae stars of around $1\%$ for the high confidence sample. We close with
two science demonstrations of our new VIVACE catalogue: first, a brief
investigation of the spatial and kinematic properties of the RR Lyrae stars
within the disc/bulge, demonstrating the spatial elongation of bar-bulge RR
Lyrae stars is in the same sense as the more metal-rich red giant population
whilst having a slower rotation rate of
$\sim40\,\mathrm{km\,s}^{-1}\mathrm{kpc}^{-1}$; and secondly, an investigation
of the Gaia EDR3 parallax zeropoint using contact eclipsing binaries across the
Galactic disc plane and bulge.
