http://arxiv.org/abs/1310.5825 discusses plasma effects on radio lensing time delays. Thoughts?

In http://arxiv.org/abs/1402.6614 we talk briefly about using strong lensing time delays to map the redshift drift over a time lag given by the images' time delays. There are quite a few things still to work out on this, such as finding ultra long delay systems and ensuring systematics don't swamp the signal. Anyone interested in collaborating on this?

If the measurement precision is good enough, then time delays of a few years might be interesting, especially because the drift measurement is differential between the images, rather than absolute. But no guarantees without more work!
For LyA I'm trying to think clearly about how we translate the measured quasar time delays into the LyA time delays (since they are at different redshifts, and hence positions along the photon paths) - I think it's straightforward if you know the cosmology but it's not clear if there's a good iterative approach.