I am currently 3rd year Physics UG and have been working on Cosmology for past 3 years.
I want to explore different areas like QFT, Quantum Gravity and maybe a bit of basic Math research as well, before I enter into PhD.(I have 2 more years of MS education)
However, with an ever increasing stress on Publications for PhD applications, it's very hard. I can try get 1-2 publications if I continue in Cosmology, as I already know the bare minimum and can start my projects with comparatively less reading. But if choose a new field I'll first have to do a lot of preliminary readings and only then start my research projects. Thus lower chance of good publications.
So how should a Physics student go about exploring different fields?
Note: [I am not considering doing a course in QFT, Math as exploring the topic]
PS: I am from India where it is much less common for UG students to get publications compared US/Europe. So, if possible, please do consider this.