Draining the Swampland
  We discuss some implications of the recently suggested Swampland conjecture
$\frac{|\nabla V|}{V}\gtrsim c\sim 1$, together with a previous one $\Delta
\phi \lesssim 1$. We list some implications for particle phenomenology and the
Early Universe. The most intriguing implication of the conjecture could be a
significant shift in allowed inflationary models, if not ruling out slow-roll
(single field) inflation altogether. The tension of inflation and the
conjecture does not only regard the amplitude of the tensor spectrum, but also
its tilt, as $c\gtrsim 1$ implies both a yet unobserved tensor to scalar ratio,
and an enhancement of the observed scalar power spectrum on large scales in
discord with current data that favors a suppression on these scales. Scalar
fields are abundant in theories of quantum gravity. Considering a second scalar
field, its dynamics are dictated by the relation between its mass, $m$, and the
Hubble parameter, $H$, at different epochs in the history of the Universe. This
scalar field, a drainon, fulfills the conjecture draining up the swampland. For
Inflation, this drainon requires a modest hierarchy compared to the inflaton.
For the rest of the thermal history of the Universe, the drainon can be a
coherently oscillating scalar field strengthening the case of Dark Matter
candidates of that sort.
