I encountered an integral
So it's a complementary error function finally.
But it seems that when x=0, the lhs of the equation is equal to 0, while at the rhs, it's equal to 1. So x=0 may not be valid for the error function, since then the integral variable x/2/sqrt(t) is all the time 0. By arguing this, I believe that when x=0, gamma = 0, but then I think that the rhs should be valid for all the finite x, which means that when x is very small but not zero, the rhs and lhs should be the same, which seems not to be the case here.... what went wrong here? Thanks