With light curve measurements, their statistical analysis, time delays and lens models all improving so that people are talking about 1% accuracy in measuring the Hubble constant with gravitational lenses, I took the opportunity of the Jodrell Bank `Golden Lenses' workshop to point out that, at this level of accuracy, one must take the other cosmological parameters, especially the inhomogeneity parameter, into account.
Note that there is a typo after Eq. (2): the limit for zero source redshift is 1, not 0. (The typo is only in the paper, not in the code, as can be seen from Figs. 4--9.)
The links below point to one file (in each case) containing the complete text, all figures and tables etc.
As are most of my publications this is available in more than one form: