I'm aware that the idea of undertaking two separate PhDs has been widely discussed in this forum, with the general consensus advising against it. However, I'm specifically interested if it's possible to pursue two PhDs in physics in distinct subfields at a US/UK university, assuming I have a genuine desire to specialize in both fields.
Here's my background:
As a current master's student on the verge of completing my program, I'm gearing up to embark on my PhD journey later this year at the same institution where I completed my undergraduate studies. My initial specialization will be in Field A, a subject I've had the pleasure of exploring for the past three years under the guidance of my professor.
However, during my master's program, I was introduced to Field B. I've found this area to be incredibly fascinating, perhaps even more so than Field A. Unfortunately, it's currently challenging for me to delve into Field B due to my lack of background in many mathematical areas. I think I'm only confident to start my PhD in Field A at this moment.
Moreover, my undergraduate institution lacks professors conducting research in Field B, which further complicates matters. This has led me to contemplate the possibility of pursuing a second physics PhD in Field B upon completing the program I'm about to begin in Field A.
I'm also aware that there are individuals who have managed to transition between different areas of interest in physics post-PhD, sidestepping the need for a second degree by opting for postdoctoral studies. However, considering the significant distinction between Fields A and B, I'm uncertain about the practicality of such a route in my case.