Can I defer a math postdoc for a year till I complete my current postdoc? I currently have a postdoc position at University X. Now, I was wondering: if I apply to math postdocs advertised by the departments in the U.S. (sth. like Szego Assistant, Benjamin Peirce etc.), would I be able to accept such a postdoc position and defer it by one year to continue my postdoc at Uni X, or is this in general impossible?
I think I've seen people doing this where they would spend one year at let's say IAS or MSRI, but I am not entirely sure if such a procedure can be negotiated or whether it is rather unlikely.
Maybe. You can't know in advance since it depends on the department's source of money, teaching needs, etc. If you apply for a position, you should at least be ready take it. You can bring up the idea of deferment, and you may get it, but you also have to be in a position to actually start when the job starts.