Searches for topological defect dark matter via non-gravitational   signatures
  We propose schemes for the detection of topological defect dark matter using pulsars and other luminous extraterrestrial systems via non-gravitational signatures. The dark matter field, which makes up a defect, may interact with standard model particles, including quarks and the photon, resulting in the alteration of their masses. When a topological defect passes through a pulsar, its mass, radius and internal structure may be altered, resulting in a pulsar `quake'. A topological defect may also function as a cosmic dielectric material with a distinctive frequency-dependent index of refraction, which would give rise to the time delay of a periodic extraterrestrial light or radio signal, and the dispersion of a light or radio source in a manner distinct to a gravitational lens. A topological defect passing through Earth may give rise to temporary non-zero electric dipole moments for an electron, proton, neutron, nuclei and atoms. The biggest advantage of such astrophysical observations over recently proposed terrestrial detection methods is the much higher probability of a defect been found in the vast volumes of outer space compared with one passing through Earth itself. 
Y. V. Stadnik, V. V. Flambaum
hep-ph astro-ph.CO astro-ph.HE nucl-th physics.atom-ph