Hi Sam, I am planning on applying this batch, however; I have a friend who just finished his Ph.d in Computer Vision. I want to work with him on a different id

Hi Sam, I am planning on applying this batch, however; I have a friend who just finished his Ph.d in Computer Vision. I want to work with him on a different idea than the one I applying for at YC(robotics). It's in the "other interests" category, he is not a co-founder for my current application. If chosen, can a founder be added iff you don't like the initial idea?