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[1004.4810] Will Multiple Probes of Dark Energy find Modifi

Posted: June 24 2010
by Molly Swanson
This is a very nicely written paper that explores how well upcoming experiments such as the Dark Energy Survey will be able to distinguish between GR+dark energy and modified gravity.

The basic idea is that different probes of dark energy (supernovae, weak lensing, large scale structure, and clusters) depend differently on the growth of structure, so a disagreement between these methods when analyzed assuming GR could provide evidence that gravity needs to be modified. They conclude that the standard method of checking the overlap of error ellipses in the w0-wa plane is not sufficiently sensitive to distinguish their toy modified gravity model from GR, and go on to develop a more sensitive method using the full multi-parameter likelihood space.

The paper also includes a really nice overview of modified gravity parameterizations and Fisher matrix methodology.

Overall I think their multi-dimensional consistency test is a fundamentally simple but powerful formalism that could be applied to many other types of consistency checks as well.

[1004.4810] Will Multiple Probes of Dark Energy find Modifi

Posted: June 26 2010
by Sarah Bridle
Yes, I agree this is a nice illustration of a basic but useful idea, and an interesting development of it.

It would be really nice if there could be a visual way of getting across the effectiveness of the multi-dimensional consistency test, that was similarly powerful to Fig 4 (e.g. some projection in n-d which shows up discrepancies??).