Do galactic bars depend on environment?: An information theoretic
  analysis of Galaxy Zoo 2
  We use an information theoretic framework to analyze data from the Galaxy Zoo
2 project and study if there are any statistically significant correlations
between the presence of bars in spiral galaxies and their environment. We
measure the mutual information between the barredness of galaxies and their
environments in a volume limited sample ($M_r \leq -21$) and compare it with
the same in datasets where (i) the bar/unbar classifications are randomized and
(ii) the spatial distribution of galaxies are shuffled on different length
scales. We assess the statistical significance of the differences in the mutual
information using a t-test and find that both randomization of morphological
classifications and shuffling of spatial distribution do not alter the mutual
information in a statistically significant way. The non-zero mutual information
between barredness and environment arises due to the finite and discrete nature
of the dataset which can be entirely explained by mock Poisson distributions.
We also separately compare the cumulative distribution functions of the barred
and unbarred galaxies as a function of their local density. Using a
Kolmogorov-Smirnov test, we find that the null hypothesis can not be rejected
even at $75\%$ confidence level. Our analysis indicates that environments do
not play a significant role in the formation of a bar, which is largely
determined by the internal processes of the host galaxy.
