What math is used the most in cosmology/astrophysics?

[astroman707]

Considering one is taking all the required math courses for a typical physics degree, what math electives are most crucial to the field of cosmology/theoretical astrophysics?
Also, is it true that mathematical modeling courses(discrete and dynamical modeling across physics) are more important to physics than pure math courses, such as real analysis?

 

[fresh_42]

Considering one is taking all the required math courses for a typical physics degree, what math electives are most crucial to the field of cosmology/theoretical astrophysics?

I think differential geometry as it also includes, i.e. requires many other techniques from other courses like topology, linear algebra, abstract algebra, functional analysis, real analysis etc.

Also, is it true that mathematical modeling courses

such as?

are more important to physics than pure math courses, such as real analysis?

How can you model something without knowing your tools?