Dilaton generation in propagation of magnetic dipole waves of pulsar in a galactic magnetic field

Abstract

This study is devoted to dilaton generation during the propagation of magnetic dipole waves from a pulsar in the galactic magnetic field. Dilaton generation occurs at cosmological scales on the order of the coherence lengths of the galactic magnetic field Lcoh, approximately 100 pc. The exact solutions of the dilaton field equation in a vacuum and in the interstellar medium with reflective index n = 1 + χ, χ ≪ 1 have been obtained, and the angular distribution of emitted dilaton energy has been determined in both cases. It has been shown that the dilaton generation intensity at first increases proportionally to r2, where r is distance from the neutron star to the observation point, then has oscillating behavior. The obtained results are applicable only for r < Lcoh. For a millisecond pulsar with a magnetic field BS ∼ 109 Gauss, located at a distance from Earth on the order of the coherence length of the galactic magnetic field Lcoh ∼ 100 pc, the obtained intensity of the dilaton generation can be greater in 100 times than the analogous intensity produced by rotating magnetic dipole momentum of a pulsar. Based on estimated values, the impact of pulsar and magnetar gravitational fields on magnetic dipole wave radiation is minimal and changes the amplitude of the waves by around 1 percent. For this reason, the effect of the gravitational field on the dilaton formation process can be disregarded in this study.