While applying for PhD in a particular topic, how useful is research in a different (maybe slightly related) topic?

Question

I have done 2 research projects on a topic, say "A". But now I am changing my field of work slightly, to say topic "B", and will do my masters thesis on "B". How useful will my projects on "A" be while applying for PhD in "B"? Will an arXiv/journal publication in "A" be comparable to one in "B", from the point of view of PhD admission committee (for graduate schools in US/UK, in particular) ?

I am a Physics master's student. The topics I mentioned above are related High Energy Physics/Gravity. "A" was mostly computational while "B" is purely theoretical.

I understand that any research is good and will add this in my CV in any case. I just want to know how good it actually is. The answer to my question will help me get an idea of graduate schools which are in my league and I could focus on those.

Thanks in advance!

Answer 1

The topics you mention (theoretical and computational aspects of high energy physics) are similar enough that any publication you get from one will be equally valuable when applying for the other. In fact, demonstrating that you have experience of both theoretical and computational work can only make your application stronger than if you had experience in only one.

Bear in mind that having a journal publication is not necessary for admission into any PhD programme that I am aware of (certainly not in UK physics). While a publication in either field that you mention would certainly boost your application, don't worry if nothing publishable comes out of your Master's. Just do good, solid work and ensure you have a strong grasp of the foundations of the field.

If you do write a paper, be sure to do it under the guidance of your Master's supervisor. They will help you organise the content and choose an appropriate journal. Submitting to arXiv is fine as long as you quickly follow it up with submission to (and hopefully acceptance in) a peer-reviewed journal.

Your supervisor (if they are active in the field) will also be able to advise you on which institutions to apply to for your PhD. When I was deciding where to apply, I mainly looked at the institutions of the authors whose papers I was frequently citing. That at least ensures your research interests will align, which is far more important than any other deciding factor (including perceived prestige of the university).

Source: I am a PhD student in physics in the UK.

Answer 2

I doubt that your admission to a program anywhere would hinge on the difference here. Doing any sort of research is a plus. You need an application showing academic success and future promise. You seem to be showing that.

Also note that arXiv is quite different from journal publishing. The former will be less valuable (if a journal article doesn't later result) due to the lower standards of "publication". But if you want qualification, I'd give the difference no more than a couple of points out of 100. But that is just a wild guess, of course. It is the admissions committee that will make the only valid judgement for such things. And they will take a fairly broad view, not focusing minutely on the details of any one thing in most cases.

But if you have done work in another field, closely related or not, don't neglect to mention it.