| 9th of November 2018 |
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| A Parkes search for fuzzy dark matter |
| by Porayko et al. |
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It is widely accepted that dark matter contributes about a quarter of
the critical mass-energy density in our Universe. The nature of dark
matter is currently unknown, with the mass of possible constituents
spanning nearly one hundred orders of magnitude! One possibility,
consisting of extremely low-mass particles and often called "fuzzy"
dark matter, would produce an oscillating gravitational potential with
nanohertz frequencies, which would result in periodic variations in
the times of arrival of radio pulses from pulsars. The Parkes Pulsar
Timing Array (PPTA) has been monitoring 20 millisecond pulsars at two-
to three-week intervals for more than a decade. In addition to the
detection of nanohertz gravitational waves, PPTA offers the
opportunity for direct searches for fuzzy dark matter in an
astrophysically feasible range of masses.
Porayko et al. have analyzed Parkes Pulsar Timing Array (PPTA) data to search for evidence of ultralight dark matter in the Galaxy. No statistically significant detection was made, and upper limits were placed on the local dark matter density, improving on previous searches by a factor of 2 to 5. The inset in the image above shows the the upper limits on the dark matter density in the Galaxy. The PPTA upper limits (using two different techniques) are shown along with projected limits in the SKA era. The full results are published in Physical Review D. (Background image credit: Alex Cherney) |