Vaselago had introduced the concept of negative refractive index materials (left handed materials (LHM)) in 1968  which exhibits a negative refractive index due to the simultaneous negative permeability and permittivity and these materials have electromagnetic properties such as negative refraction, reversed Doppler shift and reversed Cerenkov radiation
. Since Pendry  suggested that flat slab of LHM can act as a perfect lens to break the limit of diffraction due to amplifying evanescent waves, many investigations have been demonstrated theoretically and experimentally [2-5].
If neutrinos in this energy range are stable against lepton pair Cerenkov radiation
, then this sets rather strict bounds on the values of the Lorentz-violating parameters [33, 34].
Particles that travel faster than light in these substances give off energy known as Cerenkov radiation
If energetic enough, this particle will travel faster than light in the water and give rise to a shock wave of blue light called Cerenkov radiation
. This light is then detected by the photomultipliers.
AMANDA uses sensitive light detectors embedded deep in the South Polar ice to map weak flashes of light (Cerenkov radiation
) caused by neutrinos that have traveled through Earth and, coming upward from below, interact with ice molecules.
The Cerenkov radiation
is produced in a material with refractive index n by a charged particle if its velocity is greater than the local phase velocity of the light.
Instead, HESS detects very faint streaks of light (known as Cerenkov radiation
) that are produced when these gamma rays hit Earth's atmosphere.
Paula Chadwick of the University of Durham in England and her colleagues recorded flashes of blue light known as Cerenkov radiation
, which is produced when Earth's atmosphere stops incoming gamma rays.
In large water detectors, the Cerenkov radiation
produced by a charged particle above the threshold can be used for particle identification and the reconstruction of its direction and energy .