Tried again this morning after rebooting the computer -- turns out I was low on RAM yesterday evening. After starting Julia a few times to make sure it is cached I get the following results:
time julia -e '[1 2 3; 4 5 6; 7 8 9] ^ 2'
real 0m1.629s
And for Python/Numpy
time python -c 'import numpy as np; print(np.linalg.matrix_power([[1, 2, 3], [4, 5, 6], [7, 8, 9]], 2))'
real 0m0.103s
Edit: Julia Version is 0.6.3, installed directly from the Fedora 28 repositories.
Note that the majority of that time is just loading Perl 6.
time perl6 -e 'Nil'
real 0m0.156s
Perhaps someone could create a slang module for Julia in Perl 6, as that would be a fairly easy way to improve its speed.
(Assuming Julia is easy to parse and doesn't have many features that aren't already in Perl 6)
