Who picks your research topic for a PhD?

[TomServo]

For example, if your advisor specializes in gravity, but has a subfield specialty (like Horava-Lifschitz gravity) and most of their papers for the last several years are about that subspecialty, does that mean your thesis research will be about that, or could it be about any gravitational thing?

 

[jedishrfu]

Depends on what your advisor is willing to sponsor. He needs to put together a dissertation committee at some point and would need to select others qualified to review your work. Selection of topic is done between student and teacher based on the background of both people so don't be afraid to suggest a topic of interest. Also students sometimes select too big of a topic and your advisors experience can help you focus it down to something more manageable.

One thing to be aware of is that some advisors may lose interst in your work and you need to be vigilant there and not fall into the trap of not getting the support you may need otherwise you might not graduate.

 

[TomServo]

Thanks.

 

[jtbell]

[Your advisor] needs to put together a dissertation committee at some point and would need to select others qualified to review your work.

This may vary at different universities. When I was preparing for Ph.D. candidacy 35+ years ago (while finishing my initial Ph.D. coursework and after having chosen my research field and advisor), I had to round up faculty for my committee myself, after discussing my choices with my advisor. I had to take into account my department's rules for composition of the committee. As I recall, I had to have at least one theorist and one experimentalist, and one person from outside the department.