Research publications in string theory/QFT by undergrads Possible Duplicate:
  Importance of Undergraduate Research  




I am a physics undergrad interested in pursuing research in string theory/ Quantum field theory for my PhD. I am feeling pressurized by the notion, that you NEED to publish a paper to get admission to a good grad school. I was wondering how common is it for a undergrad to write a research paper in these areas? Do most of the students selected for PhD admission in these areas at top universities already have research publications? Also how much is an undergrad aspiring to pursue these areas know before entering grad school.
I'm not in the same area as you are, so I couldn't speak for students in theoretical physics. However, generally speaking, a publication doesn't make or break a graduate application. They are definitely a plus, but I don't believe any department would simply reject a student because they have no publications.

If you wanted to find out if graduate students in your area had journal articles published during their undergraduate, you can browse the websites for the related departments of schools you are interested in. Almost all of them have lists of their graduate students, some of which may have uploaded their resumes. You can check the dates on their publications.

Although I said publications don't make or break an application, previous work including internships, projects, research with an advisor in a related area is definitely a must. You are required to show that your interests led you to pursue further work in your fields of interest. This doesn't even have to be the same field that you are applying to graduate school for. But you are required to demonstrate that you are willing to put in the time and effort to go above and beyond in what you like to do.