Our research is based on the technique of pulsar timing, and what we can learn about the Solar System, the Milky Way and the Universe, by observing pulsars at radio frequencies. The following specific research projects form the core of our work:
Gravitational wave detection:
We are part of the international effort to make the first direct detection of
gravitational waves. The gravitational waves we expect to detect,
originate in supermassive binary black holes, which are a necessary
consequence of galaxy evolution (according to the standard model). So
a positive detection will not only lift the final veil of Einstein's
theory of relativity, but will also tell us a lot more about how
galaxies form and evolve, and about the role dark matter plays in the
Universe.
Low-frequency pulsar observations and the interstellar medium:
We use the low-frequency array (LOFAR)
to observe pulsars and to measure the dispersion of the pulsed
signals, at unprecedented precision. Firstly this allows us to correct
for these dispersive delays (which can help the gravitational-wave
detection efforts mentioned above); and secondly we can get a very
precise view of the densities and turbulence of interstellar gas
clouds, which is a useful probe of Galactic dynamics at the smallest
scales.
Timing of close and relativistic binary pulsars:
The high-precision timing possible today, allows very precise
measurements of the binary systems some pulsars inhabit. This the case
of double neutron stars, this enables highly precise tests of
relativistic gravity and in the case of pulsars in close orbits with
semi-degenerate stars, it provides insight into the interior and winds
of these stars, which cannot be probed otherwise.
Besides these main topics, we are interested in a variety of pulsar-related research, including pulsar population statistics, single pulse studies, pulsar mass measurements, development of techniques and code for pulsar timing analyses and pulsar timing stability analysis.