Name: Rose Lerner
 Institution: Lancaster University
 Title: Detectability of Higgs inflation and its variants
 Key Words: inflation, dark matter, Higgs boson
 Abstract: We show how the Higgs mass (m_H) and CMB spectral
index (n) are sufficient to distinguish between Higgs inflation
(where the inflaton is the standard model Higgs boson with a
large non-minimal coupling to gravity) and its variants (which
include non-minimally coupled scalar dark matter). We find
radiative corrections cause the common classical value (n =
0.966) to decrease with m_H for Higgs inflation and increase
with m_H where the inflaton is scalar dark matter. The models
are clearly observationally distinct and well within the reach
of Planck and LHC. To complete the second model, we demonstrate
that reheating is possible for the case of a stable scalar
dark-matter inflaton. We then review the apparent problem of
unitarity violation in these models and conclude that it is not
possible at present to prove whether or not this is a problem
for the models. Assuming that there is unitarity violation, we
present a new, unitarity-conserving model of Higgs inflation.
This predicts a larger classical value for the spectral index
(n = 0.974). Thus we conclude that Higgs inflation and its
variants are important models which should not be dismissed
before confrontation with data from LHC, Planck and dark matter
detection experiments.