Some Inconvenient Truths
  A recent paper by Fr\"ob employs the linearized Weyl-Weyl correlator to
construct the tensor power spectrum. Although his purpose was to argue that
infrared divergences and secular growth in the graviton propagator are gauge
artefacts, a closer examination of the problem leads to the opposite
conclusion. The analogies with the BMS symmetries of graviton scattering on a
flat background, and with the Aharonov-Bohm effect of quantum mechanics,
suggest that de Sitter breaking secular growth is likely to be observable in
graviton loop effects. And a recent result for the vacuum polarization does
seem to show it.
