Evidence for departure from \Lambda CDM with LSS
  We investigate the growth index parameter \gamma and the time variation of
the gravitational constant G_{eff} by using the currently available growth
function f(z) data at different redshifts, with and without scaling to the
fiducial \Lambda CDM model. We inquire the four different models of \gamma
including a constant \gamma. From a \chi^2 minimization, we constrain the
parameter spaces of models and show that \Lambda CDM model is excluded by
1-\sigma level from current f(z) data. G_{eff} is different from the Newton's
gravitational constant G_{N} in modified gravity theories and interestingly,
the current data shows that G_{eff} \neq G_{N} at z \gtrsim 0.2 \sim 0.3 at
3-\sigma level. From these, we conclude that Einstein's General Relativity with
\Lambda CDM is ruled out by 99% confidence level from large scale structure
observations.
