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Speaker |
Flambaum, Victor |
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Coauthors |
Stadnik, Yevgeny |
| Talk Title |
Searching for dark matter through observations of double neutron stars |
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Abstract |
Topological defects are stable, extended-in-space configurations of scalar, pseudoscalar or vector fields, which can have a variety of dimensionalities (0D: monopole, 1D: string, 2D: domain wall), and may contribute to the dark matter content of the universe. Networks of topological defects are believed to have assisted in observed cosmological structure formation. Traditionally, these objects have been sought for in astrophysical systems via their gravitational effects. We propose to search for defects in astrophysical systems via non-gravitational effects. Double neutron stars, especially binary pulsars, are ideal candidates for such searches. When a topological defect passes through a pulsar, the frequency of pulsar rotation, as well as its mass, radius and possibly internal structure may be altered. This may generate a pulsar ‘quake’ or glitch for a sufficiently small and/or rapidly travelling defect. Defects may offer a possible explanation for conventional pulsar glitches, but if they do not cause traditional glitches in pulsars, then defects may still induce smaller glitch-like events (which last several seconds or minutes). In the case of a binary pulsar system, similar effects are expected to be observed in both pulsars, separated by a relatively small time interval. Defects may also function as a cosmic dielectric material with a distinctive frequency-dependent index of refraction, giving rise to the time delay of binary pulsar signals and frequency-dependent lensing (rainbow effect) when a defect passes through the line-of-sight connecting a binary pulsar and Earth. Our proposed detection methods are complementary to recently proposed laboratory detection schemes for topological defects. References: [1] Y. V. Stadnik and V. V. Flambaum. Phys. Rev. Lett. 113, 151301 (2014). [2] M. Pospelov, S. Pustelny, M. P. Ledbetter, D. F. Jackson Kimball, W. Gawlik, and D. Budker. Phys. Rev. Lett. 110, 021803 (2013). [3] A. Derevianko and M. Pospelov. Nature Physics 10, 933 (2014). [4] Y. V. Stadnik and V. V. Flambaum. Phys. Rev. Lett. 114, 161301 (2015). |
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