Cosmological constraints on dark matter annihilation and decay:
  Cross-correlation analysis of the extragalactic $\gamma$-ray background and
  cosmic shear
  We derive constraints on dark matter (DM) annihilation cross section and
decay lifetime from cross-correlation analyses of the data from Fermi-LAT and
weak lensing surveys that cover a wide area of $\sim660$ squared degrees in
total. We improve upon our previous analyses by using an updated extragalactic
$\gamma$-ray background data reprocessed with the Fermi Pass 8 pipeline, and by
using well-calibrated shape measurements of about twelve million galaxies in
the Canada-France-Hawaii Lensing Survey (CFHTLenS) and Red-Cluster-Sequence
Lensing Survey (RCSLenS). We generate a large set of full-sky mock catalogs
from cosmological $N$-body simulations and use them to estimate statistical
errors accurately. The measured cross correlation is consistent with null
detection, which is then used to place strong cosmological constraints on
annihilating and decaying DM. For leptophilic DM, the constraints are improved
by a factor of $\sim100$ in the mass range of O(1) TeV when including
contributions from secondary $\gamma$ rays due to the inverse-Compton
upscattering of background photons. Annihilation cross-sections of $\langle
\sigma v \rangle \sim 10^{-23}\, {\rm cm}^3/{\rm s}$ are excluded for TeV-scale
DM depending on channel. Lifetimes of $\sim 10^{25}$ sec are also excluded for
the decaying TeV-scale DM. Finally, we apply this analysis to wino DM and
exclude the wino mass around 200 GeV. These constraints will be further
tightened, and all the interesting wino DM parameter region can be tested, by
using data from future wide-field cosmology surveys.
