Related papers: Faster than light in a birefringent crystal
The diffraction effects on gravitational waves propagating through a stellar cluster are analyzed in the relevant approximation of Fresnel diffraction limit. We find that a gravitational wave scintillation effect - similar to the radio…
An evanescent wave is a non-propagating wave with an imaginary wave vector. In this study, we prove that these are solutions of the tachyon-like Klein Gordon equation, and that in the tunneling of ultrarelativistic half integer spin…
We study wave propagation in strongly nonlinear 1D diatomic granular crystals under an impact load. Depending on the mass ratio of the `light' to `heavy' beads, this system exhibits rich wave dynamics from highly localized traveling waves…
Wave propagation in spatially periodic media, such as photonic crystals, can be qualitatively different from any uniform substance. The differences are particularly pronounced when the electromagnetic wavelength is comparable to the…
This paper examines some of the recent experiments on superluminal propagation. It is well known that Sommerfeld and Brillouin analyzed a rectangular sinusoidal signal propagating through a dispersive medium and derived expressions to…
Anomalous dispersion cannot occur in a transparent passive medium where electromagnetic radiation is being absorbed at all frequencies, as pointed out by Landau and Lifshitz. Here we show, both theoretically and experimentally, that…
It is shown that negative electric permittivity and magnetic permeability recently discovered in a photonic crystal in the vicinity of the Gamma-point are properties of propagating modes only. The evanescent modes rather decay than increase…
The linear birefringence of uniaxial crystal plates is known since the 17th century, and it is widely used in numerous optical setups and devices. Here we demonstrate, both theoretically and experimentally, a fine lateral circular…
One phenomenological explanation of superluminal propagation of neutrinos, which may have been observed by OPERA and MINOS, is that neutrinos travel faster inside of matter than in vacuum. If so neutrinos exhibit refraction inside matter…
In a recent theoretical article [Eur. Phys. J. D 70, 1 (2016)], Kazemi et al. claim to have demonstrated superluminal light transmission in an optomechanical system where a Bose-Einstein condensate serves as the mechanical oscillator. In…
Light propagation is investigated in the context of local anisotropic nonlinear dielectric media at rest with the dielectric coefficients $\epsilon^\mu{}_\nu = \epsilon^\mu{}_\nu (\vec{E},\vec{B})$ and constant $\mu$, in the limit of…
We study the wave propagation in nonlinear electrodynamical models. Particular attention is paid to the derivation and the analysis of the Fresnel equation for the wave covectors. For the class of general nonlinear Lagrangian models, we…
The quantum gravity effects of vacuum polarization of gravitons propagating in a curved spacetime cause the quantum vacuum to act as a dispersive medium with a refractive index. Due to this dispersive medium gravitons acquire superluminal…
A time-resolved analysis of the amplitude and phase of THz pulses propagating through three-dimensional photonic crystals is presented. Single-cycle pulses of THz radiation allow measurements over a wide frequency range, spanning more than…
One may believe that front velocities of waves in a given theory coincide with the UV limit of phase velocities for any dispersion relations. This implies that IR physics is irrelevant to the discussion of propagation speed of waves. We…
We show that diffraction of electromagnetic radiation (in particular of a visible light) can disappear in propagation through materials with periodically in space modulated refraction index, i.e. photonic crystals. In this way the light…
A near-field analysis based on Maxwells equations is presented which indicates that the fields generated by both an electric and a magnetic dipole or quadrapole, and also the gravitational waves generated by a quadrapole mass source…
We have experimentally observed superluminal and infinite group velocities in bulk hexagonal two-dimensional photonic bandgap crystals with bandgaps in the microwave region. The group velocities depend on the polarization of the incident…
We investigate light propagation through materials with periodically modulated gain/loss profile in both transverse and longitudinal directions, i.e. in material with two-dimensional modulation in space. We predict effects of…
We show that dispersive gravitational waves, as a background spacetime, can reflect electromagnetic waves in a plasma. This reflection upshifts the frequency of the reflected wave, being larger for low-frequency incident waves. This effect…