Year: 2006
Type: article
Abstract: We present exact solutions of the massless Klein-Gordon equation in a spacetime in which an infinite straight cosmic string resides. The first solution represents a plane wave entering perpendicular to the string direction. We also present and analyze a solution with a static pointlike source. In the short wavelength limit these solutions approach the results obtained by using the geometrical optics approximation: magnification occurs if the observer lies in front of the string within a strip of angular width $8\ensuremath{\pi}G\ensuremath{\mu}$, where $\ensuremath{\mu}$ is the string tension. We find that when the distance from the observer to the string is less than ${10}^{\ensuremath{-}3}(G\ensuremath{\mu}{)}^{\ensuremath{-}2}\ensuremath{\lambda}\ensuremath{\sim}150\text{ }\text{ }\mathrm{Mpc}(\ensuremath{\lambda}/\mathrm{AU})(G\ensuremath{\mu}/{10}^{\ensuremath{-}8}{)}^{\ensuremath{-}2}$, where $\ensuremath{\lambda}$ is the wavelength, the magnification is significantly reduced compared with the estimate based on the geometrical optics due to the diffraction effect. For gravitational waves from neutron star (NS)-NS mergers the several lensing events per year may be detected by DECihertz interferometer gravitational wave observatory (DECIGO)/big bang observer (BBO).
Institutions: Kyoto University, National Astronomical Observatory of Japan
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2038055697