Angular inflation in multi-field ${\alpha}$-attractors
  We explore the dynamics of multi-field models of inflation in which the
field-space metric is a hyperbolic manifold of constant curvature. Such models
are known as $\alpha$-attractors and their single-field regimes have been
extensively studied in the context of inflation and supergravity. We find a
variety of multi-field inflationary trajectories in different regions of
parameter space, which is spanned by the mass parameters and the hyperbolic
curvature. Amongst these is a novel dynamical attractor along the boundary of
the Poincare disc which we dub "angular inflation". We calculate the evolution
of adiabatic and isocurvature fluctuations during this regime and show that,
while isocurvature modes decay during this phase, the duration of the angular
inflation period can shift the single-field predictions of $\alpha$-attractors.
For highly curved field-space manifolds, this can lead to predictions that lie
outside the current observational bounds.
