  Starting from Einstein-Yang-Mills in higher dimensions with an instanton on a
compact sphere, we dimensionally reduce to find an effective four-dimensional
action describing "hilltop" inflation. Using recent CMB data, we analyse the
parameter space of this model to search for viable set-ups. One unique feature
of this class of inflationary models is that the value of the inflaton field,
or alternatively, the size of the compact sphere, is stabilised dynamically
during the inflationary process.
