Dilaton photoproduction in a magnetic dipole field of pulsars and magnetars

Abstract

According to Einstein-Maxwell-Dilaton theory, the dilaton field $\psi$ can be produced by electromagnetic fields with non-zero Maxwell invariant. So electromagnetic wave propagating in an external electromagnetic field is a typical source of dilaton radiation. For study dilaton photoproduction in astrophysical conditions it's interesting to consider plane elliptically polarized electromagnetic wave propagating in the electromagnetic field of magnetic dipole ${\bf m}$ of pulsars and magnetars. The dilation field equation is solved in case $|\psi| \ll 1$. The angular distribution dilaton radiation is studied in every point of space. It's shown that spectral composition of dilatons is similar to spectral composition of plane electromagnetic wave. Amount of dilaton energy radiated in time and all directions is greatest in condition $(B_1^2-B_2^2)(m_x^2-m_y^2)\geq 0,$ where $B_1$ and $B_2$ are electromagnetic wave amplitudes along the axes of polarization ellipse. This condition is valid for many neutron star systems.