(the presence of a constant vector nμ violates Lorentz
invariance). Such a term leads to a different velocity for
the two circular polarizations of light, a phenomenon
known as birefringence. If light is longitudinally polarized
at the source (through a certain combination of the
two circular polarizations), then the polarization vector
will rotate along the direction of propagation, because
of refringence. Over large distances, longitudinal polarization
will be lost. This effect has been used to put limits
on the Lorentz violating coupling ξ by measuring the
linear polarization of distant gamma ray bursts with the
INTEGRAL satellite [15]. One achieves ξ < 1.1 10−14
which shows that scales larger than the Planck scale are
probed; interesting limits on dimension 6 operators start
being within reach. Similar limits are obtained with
FERMI, although not as constraining, by using the dependence
of the speed of light on the photon energy
[16].
(the presence of a constant vector nμ violates Lorentzinvariance). Such a term leads to a different velocity forthe two circular polarizations of light, a phenomenonknown as birefringence. If light is longitudinally polarizedat the source (through a certain combination of thetwo circular polarizations), then the polarization vectorwill rotate along the direction of propagation, becauseof refringence. Over large distances, longitudinal polarizationwill be lost. This effect has been used to put limitson the Lorentz violating coupling ξ by measuring thelinear polarization of distant gamma ray bursts with theINTEGRAL satellite [15]. One achieves ξ < 1.1 10−14which shows that scales larger than the Planck scale areprobed; interesting limits on dimension 6 operators startbeing within reach. Similar limits are obtained withFERMI, although not as constraining, by using the dependenceof the speed of light on the photon energy[16].
การแปล กรุณารอสักครู่..