Constraining Ho\v{r}ava-Lifshitz gravity by weak and strong
  gravitational lensing
  We discuss gravitational lensing in the Kehagias-Sfetsos space-time emerging
in the framework of Ho\v{r}ava-Lifshitz gravity. In weak lensing we show that
there are three regimes, depending on the value of $\bar {\lambda}=1/\omega
d^{2}$, where $\omega $ is the Ho\v{r}ava-Lifshitz parameter and $d$
characterizes the lensing geometry. When $\bar {\lambda}$ is close to zero,
light deflection typically produces two images, as in Schwarzschild lensing.
For very large $\bar {\lambda}$ the space-time approaches flatness, therefore
there is only one undeflected image. In the intermediate range of $\bar
{\lambda}$ only the upper focused image is produced due to the existence of a
maximal deflection angle $\delta_{max}$, a feature inexistent in the
Schwarzschild weak lensing. We also discuss the location of Einstein rings, and
determine the range of the Ho\v{r}ava-Lifshitz parameter compatible with
present day lensing observations. Finally, we analyze in the strong lensing
regime the first two relativistic Einstein rings and determine the constraints
on the parameter range to be imposed by forthcoming experiments.
