A numerical method is presented for determining the transmittance of long-period (LP) fiber-gratings having arbitrary azimuthal/radial refractive index variations. The method uses coupled-mode theory and includes both the sine and cosine character of the LP modes. The model treats interactions between the fundamental mode and high-azimuthal-order cladding modes. The method utilizes the transfer...

The theory of magnetohydrodynamic (MHD) waves in solar coronal slabs in a zero-β configuration and for parallel propagation of waves does not allow the existence of surface waves. When oblique propagation of perturbations is considered both surface and body waves are able to propagate. When the perpendicular wave number is larger than a certain value, the body kink mode becomes a surface wave. ...

The possibility of a resonant excitation of a free oscillation mode with an observed period of 4.2311 d in the star 51 Pegasi by the tidal action of a low-mass companion is investigated. A free oscillation mode with the observed period is shown to correspond to a g+-mode of a high radial order. For the determination of the tidal displacement in a component of a close binary system of stars near...