Global portraits of nonminimal teleparallel inflation

Understand

We construct the global phase portraits of inflationary dynamics in teleparallel gravity models with a scalar field nonminimally coupled to torsion scalar.

• The adopted set of variables can clearly distinguish between different asymptotic states as fixed points, including the kinetic and inflationary regimes.
• The key role in the description of inflation is played by the heteroclinic orbits which run from the asymptotic saddle points to the late time attractor point and are approximated by nonminimal slow roll conditions.
• To seek the asymptotic fixed points we outline a heuristic method in terms of the "effective potential" and "effective mass", which can be applied for any nonminimally coupled theories.