![Figure 3](lpi.png)
Figure 3: Selected tests of local position invariance via gravitational redshift experiments, showing
bounds on
, which measures degree of deviation of redshift from the formula
.
In null redshift experiments, the bound is on the difference in
between different kinds of clocks.
![α](article82x.gif)
![Δ ν∕ν = ΔU ∕c2](article83x.gif)
![α](article84x.gif)