Exploring BB as a theoretical physicist or astrophysicist?

[Pleonasm]

I am curious as to the differences, if one wishes to study the big bang and the origin of the universe, as his/hers primary studies. How would my field of study, and expertise differ coming from a theoretical physics background, compared to (theoretical) astrophysics?

Would there be any practical differences in the workings as a theoretical astrophysicist, compared to being a theoretical physicist, interested in cosmology, such as Lawrence Krauss? I am I bound under more regulations as the astrophysicist, compared to a theoretical physicist?

Which of the two disciplines is normally prefered, and would an astrophysics background still allow for speculations about Relativity and Quantum Mechanics role in these events, in my eventual papers?

It's the same event unfolding, so how would the respectivr field differ?

 

[Orodruin]

In the end, your background is going to be irrelevant for what arguments you are allowed to make. The only thing that will change is what kind of arguments you will be comfortable with making. Your research will in many ways be dictated by several factors, such as the research interests of your eventual supervisor, but at some point in an academic career you will be able to lean towards the kind of studies that you would like to make, or look for a position that will enable you to do so.

 

[Pleonasm]

I guess what I am trying to get across is; would there be a fundamental difference in how I approach the subject, despite the fact that it's the identical event for both a TP and AP? If so, what would those difference be in practice?