Binary-induced spiral arms inside the disc cavity of AB Aurigae
  In this work we demonstrate that the inner spiral structure observed in AB
Aurigae can be created by a binary star orbiting inside the dust cavity. We
find that a companion with a mass-ratio of 0.25, semi-major axis of 40 au,
eccentricity of 0.5, and inclination of 90{\deg} produces gaseous spirals
closely matching the ones observed in $^{12}$CO (2-1) line emission. Based on
dust dynamics in circumbinary discs (Poblete, Cuello, and Cuadra 2019), we
constrain the inclination of the binary with respect to the circumbinary disc
to range between 60{\deg} and 90{\deg}. We predict that the stellar companion
is located roughly 0.18 arcsec from the central star towards the
east-southeast, above the plane of the disc. Should this companion be detected
in the near future, our model indicates that it should be moving away from the
primary star at a rate of 6 mas/yr on the plane of the sky. Since our companion
is inclined, we also predict that the spiral structure will appear to change
with time, and not simply co-rotate with the companion.
