In one of my PhD thesis chapters, I have a derivation of a theory that I have proposed in the paper. I just found out that I have made an error in the calculation, and my derivation is flawed. The chapter is yet to be submitted in a journal, so it has never been peer reviewed. I never saw the flaw before this. Do I bring it up during my defense? And what do I say if the committee asks me about it? Can that have a negative outcome on my defense result?
I am feeling scared now!
Should I mail my advisor? My defense is on Monday afternoon and I don't know what to do!