December 21st, 2009, 6:01 pm
If you are in a standard BS world there is no smile. So all vols are the sameWhen you have a smile this is mapped into LV for diffusions causing the following drift:drift = sigma_eq(S,t) * sigma_fx(FX,t) *rho(t), where sigma(S,t) is the LV for the equity diffusion and sigma(FX,t) is the local vol for the FX diffusionCheers