Hello everyone. I am an undergraduate senior anticipating degrees in both physics and astrophysics this spring. Until about a year ago I wasn't particularly sure what I wanted to do after graduation. However, after taking upper division QM and particle physics courses I've developed a great interest in pursuing high energy theory. So for this admissions season I sent out 13 applications to various top 40 physics graduate schools. I stated HET and particularly string theory as my research interests. Just a few days ago I received my first acceptance, and so naturally I am quite happy and relieved. However, I do have one big concern. In the process of getting my double major I never had any scheduling room to take math courses beyond the standard requirement. That is, I took the Calc 1-4 sequence and one additional course in "foundations", which was basically a course on proofs. It has been over two years since then, and I am concerned that my deficiency in higher level math courses could make it challenging for me to pursue string theory. I am aware that real/complex analysis, group theory, topology, differential geometry, and many advanced topics are important to string theory. My fear is that I may be shoved into some other research area or not be able to join my desired research group due to this deficiency in the aforementioned topics. Is this a valid concern, or is it normal for theory graduate students to need additional coursework in those topics after arrival? To my understanding, new physics grad students are kept busy with all the advanced courses related directly to the major. Would there be much room (or would it even be possible) to cram a few math courses in there? Or, is the required depth in those topics not enough to justify taking entire courses on them? I.e, do most students just cover them through self study? In any case, there are basically three options I have: 1) Decline all my offers and go into a 5th year as an undergrad and take several relevant math courses. 2) Accept one of the offers and just hope it doesn't matter. 3) Accept, but ask for a 1-year deferral and take courses in the mean time. I am really hoping that it will be ok for me to just accept an offer and that my fears are poorly based. If anyone has had a similar experience or has a suggestion for what I should do, it would be greatly appreciated.