[1003.2185] Confirmation of general relativity on large sca
Posted: March 11 2010
The authors introduce a new statistic which eliminates both galaxy bias and sigma8 through the combination of galaxy-galaxy clustering, galaxy-galaxy lensing, and a measurement of redshift space distortions from anisotropic galaxy clustering. The authors present new measurements of the first two, and rely on Tegmark et al. (2006) for a measurement of [tex]\beta[/tex] from redshift space distortions.
It can be used as a test of GR (and to constrain models of modified gravity). The statistic is
[tex]E_G = \frac{1}{\beta} \frac{\Gamma_{gm}(R)}{\Gamma_{gg}(R)}[/tex]
which in GR+[tex]\Lambda[/tex]CDM is [tex]\Omega_{m,o}/f(z) = 0.408 \pm 0.029[/tex].
Their measurements are in agreement with [tex]N[/tex]-body + HOD mock LRG catalogs, indicating that the measurement is robust to non-linearities.
They compare to the predictions of f(R) and TeVeS, which predict substantially different values than GR+[tex]\Lambda[/tex]CDM. While the errors are still quite large, this should prove to be an extremely valuable statistic in the near future.
It can be used as a test of GR (and to constrain models of modified gravity). The statistic is
[tex]E_G = \frac{1}{\beta} \frac{\Gamma_{gm}(R)}{\Gamma_{gg}(R)}[/tex]
which in GR+[tex]\Lambda[/tex]CDM is [tex]\Omega_{m,o}/f(z) = 0.408 \pm 0.029[/tex].
Their measurements are in agreement with [tex]N[/tex]-body + HOD mock LRG catalogs, indicating that the measurement is robust to non-linearities.
They compare to the predictions of f(R) and TeVeS, which predict substantially different values than GR+[tex]\Lambda[/tex]CDM. While the errors are still quite large, this should prove to be an extremely valuable statistic in the near future.