Non-singular exponential gravity: a simple theory for early- and
  late-time accelerated expansion
  A theory of exponential modified gravity which explains both early-time
inflation and late-time acceleration, in a unified way, is proposed. The theory
successfully passes the local tests and fulfills the cosmological bounds and,
remarkably, the corresponding inflationary era is proven to be unstable.
Numerical investigation of its late-time evolution leads to the conclusion that
the corresponding dark energy epoch is not distinguishable from the one for the
$\Lambda$CDM model. Several versions of this exponential gravity, sharing
similar properties, are formulated. It is also shown that this theory is
non-singular, being protected against the formation of finite-time future
singularities. As a result, the corresponding future universe evolution
asymptotically tends, in a smooth way, to de Sitter space, which turns out to
be the final attractor of the system.
