Studying How do you deal with weak background at the start of PhD?

  • Thread starter Thread starter MadAtom
  • Start date Start date
  • Tags Tags
    Phd Weak
AI Thread Summary
Starting a PhD in General Relativity can be daunting, especially when feeling unprepared in Quantum Field Theory (QFT). It's important to communicate with your supervisor about expectations and focus on your research rather than solely on coursework. Many have faced similar challenges and found that mastering foundational topics can take time, but it is possible to succeed through independent study and leveraging personal strengths. Embracing the learning process and accepting gaps in knowledge as part of academic growth can alleviate psychological burdens. Ultimately, building confidence in your abilities and focusing on your research will lead to success in your PhD journey.
MadAtom
Messages
37
Reaction score
0
Hi all,

I just started in a PhD in a General Relativity related problem. Although the problems that I am going to work with are purely classical (in the sense of no QM required), I feel bad about my lack of proficiency in QFT.

I had to follow a course in some advanced topics (such as String theory and CFT), which is mandatory for the program I am in, and I was really lost. I understood the ideais, but I really struggled with the exercises, because of my lack of "experience" in QFT problems. My QFT course was really introductory and I did very few exercises.

For example, when someone asked me to apply Wick contraction, I had to go back to textbooks, because it is not something I have from top of my head, and I did not do many exercises on it at the time.

So my question is, how do you tackle this problem? The feeling that you lack some foundations, even though they are not really important to what you do, but you think that a well rounded physics should know. How do you convince yourself that "it is OK" to have these deficiencies or, rather, that it is not?

Sorry for the vagueness in this question.

MA
 
Physics news on Phys.org
This sounds like a good topic for discussion between you and your supervisor.

I know, at the start of a PhD, you would likely rather impress your supervisor than walk in and admit that you're not as strong as you'd like to be in a particular area. But ignoring the problem or simply hoping that it won't be important in the long run doesn't seem like the best way to tackle it. At the same time, I can also appreciate that one can't be an expert in everything and at some point you have to focus. But this is why such a question is best discussed with someone who has expertise in your area. Your supervisor should have an idea of how strong your QFT foundation needs to be, even if it's just for passing your qualification and/or candidacy exams. Once you have a sense of how strong that really should be, you can develop a strategy for addressing it. That could include revisiting the prerequisite courses, finding a decent problem set to work through, auditing another course, etc. and balancing all of that with making progress on your research project.
 
  • Like
Likes yucheng, mpresic3, marcusl and 2 others
MadAtom said:
So my question is, how do you tackle this problem? The feeling that you lack some foundations, even though they are not really important to what you do, but you think that a well rounded physics should know. How do you convince yourself that "it is OK" to have these deficiencies or, rather, that it is not?
I sympathize. Personal story: Embarked on a PhD in high-energy physics when, just a year before, I had casually remarked that I would get my experimental physics masters pretty soon without knowing anything at all about elementary particles. Following some lectures for theoretical masters students (field theory, phenomenology of elementary particles, both given by later Nobel prize winners! :smile: ) did not help me much further. Nor did a series of lectures later on at CERN by Victor Weisskopf
One of his few regrets was that his insecurity about his mathematical abilities may have cost him a Nobel prize when he did not publish results (which turned out to be correct) about what is now known as the Lamb shift.[6]
And, still later at SLAC, a series of QFT lectures by John Dirk Walecka -- they were aimed at theoretical physics graduate students and way above my abstraction level. Couldn't finish a single execise on my own. I kept the notes and the book for fourty years but now I'm going to chuck them out (anyone a good offer for Itzykson and Zuber: QFT ?).

You simply can't know everything. But you can still achieve a PhD for what you can know and do (as you understand, I got mine -- in experimental physics).

Choppy said:
This sounds like a good topic for discussion between you and your supervisor.
I second Choppy: you have been selected for a reason (that you apparently still have to find out). Find out what the expectations are (and manage them if unrealistic). Find your forte and thrive.

##\ ##
 
  • Informative
Likes MadAtom
MadAtom said:
Hi all,

I just started in a PhD in a General Relativity related problem. Although the problems that I am going to work with are purely classical (in the sense of no QM required), I feel bad about my lack of proficiency in QFT.

I had to follow a course in some advanced topics (such as String theory and CFT), which is mandatory for the program I am in, and I was really lost. I understood the ideais, but I really struggled with the exercises, because of my lack of "experience" in QFT problems. My QFT course was really introductory and I did very few exercises.

For example, when someone asked me to apply Wick contraction, I had to go back to textbooks, because it is not something I have from top of my head, and I did not do many exercises on it at the time.

So my question is, how do you tackle this problem? The feeling that you lack some foundations, even though they are not really important to what you do, but you think that a well rounded physics should know. How do you convince yourself that "it is OK" to have these deficiencies or, rather, that it is not?

Sorry for the vagueness in this question.

MA

I'd slow down. Focus more on passing your general exams rather than wowing your research supervisor and peers. Coming from LSU, I had a pretty weak background among my peers at MIT. After a frank discussion with both my research supervisor and academic advisor, my plan was to retake the four core undergraduate courses my first year, and focus additional independent study on the first general exam. It felt remedial taking undergrad E&M, Stat Mech, Quantum Mechanics, and Classical Mechanics over again. But I gained a level of mastery that served me well not only on the PhD qualifying exams, but throughout my research and teaching career. The course load was also light enough that I could begin being active in the research program - mostly coming up the learning curve, but making a few small contributions based more on my technical skills than on my physics knowledge.

It took me several years before I was really ready or any advanced topics. The first year was retaking undergrad courses, and the next couple were taking the meat and potatoes grad courses in prep for the 2nd PhD qualifying exam.

It was a slow start, but by my third year, I was in demand as a collaborator both in the department and beyond since my programming skills and computational prowess put some tools in my toolbox that other groups appreciated (as well as my research advisor). By the time I completed my PhD, I had been a co-author on 8 theory papers and first author on four.
 
  • Like
Likes Munnu, MadAtom and BvU
Choppy said:
This sounds like a good topic for discussion between you and your supervisor.

Thank you for the input! In fact my supervisor is not too much concerned about my performance in those courses, but just on the research itself. And for the research that I am going to do, these deficiencies that I have in QFT will not weigh that much.

But it is more of a psychological burden. It weighs on my conscience not to know certain things.

But I guess I have to start becoming more comfortable with my own ignorance in order to move forward, and realize that academic life is marked by never-ending learning...
 
BvU said:
Find your forte and thrive.
##\ ##
Thank you for sharing this!
 
Hey, I am Andreas from Germany. I am currently 35 years old and I want to relearn math and physics. This is not one of these regular questions when it comes to this matter. So... I am very realistic about it. I know that there are severe contraints when it comes to selfstudy compared to a regular school and/or university (structure, peers, teachers, learning groups, tests, access to papers and so on) . I will never get a job in this field and I will never be taken serious by "real"...
Yesterday, 9/5/2025, when I was surfing, I found an article The Schwarzschild solution contains three problems, which can be easily solved - Journal of King Saud University - Science ABUNDANCE ESTIMATION IN AN ARID ENVIRONMENT https://jksus.org/the-schwarzschild-solution-contains-three-problems-which-can-be-easily-solved/ that has the derivation of a line element as a corrected version of the Schwarzschild solution to Einstein’s field equation. This article's date received is 2022-11-15...

Similar threads

Replies
19
Views
4K
Replies
1
Views
72
Replies
4
Views
939
Replies
4
Views
2K
Replies
9
Views
2K
Back
Top