On the geometrical interpretation of scale-invariant models of inflation
  We study the geometrical properties of scale-invariant two-field models of inflation. In particular, we show that when the field-derivative space in the Einstein frame is maximally symmetric during inflation, the inflationary predictions can be universal and independent of the details of the theory. 
Georgios K. Karananas, Javier Rubio
hep-ph astro-ph.CO gr-qc hep-th