Measurement of anisotropy of dark matter velocity distribution using
  directional detection
  Although the velocity distribution of dark matter is assumed to be generally
isotropic, some studies have found that $\sim\hspace{-0.1cm}25$\% of the
distribution can have anisotropic components. As the directional detection of
dark matter is sensitive to both the recoil energy and direction of nuclear
recoil, directional information can prove useful in measuring the distribution
of dark matter. Using a Monte Carlo simulation based on the modeled directional
detection of dark matter, we analyze the differences between isotropic and
anisotropic distributions and show that the isotropic case can be rejected at a
90\% confidence level if $O(10^4)$ events can be obtained.
