Good morning, (i) Where will I find the definition of a complete market in the notes, I do not recall seeing this anywhere (iii) How do we know that we should use W~t=Wt+Lt for some constant L? In the notes it says some gamma(t) exists which suggests a function of t exists. Do we just know for geometric Brownian motion that it is Lt because we need dW~t=dWt+Ldt, so that the drift term can be made to equal 0? Thank you
(i) Chapter 16, Page 8. (ii) Yes, it is as you say. Because mu and sigma are constant in the opening SDE then L only needs to be a constant in order to force the drift term to zero.