[1004.4810] Will Multiple Probes of Dark Energy find Modifi
Posted: June 24 2010
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.
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.