Scientists find new ways to detect high-frequency gravitational waves

The groundbreaking concept proposed by HKUST Department of Physics Prof. Liu's team allows a single astronomical telescope in the Earth's magnetosphere to function as a detector for GW signals. Credit: HKUST

A team of researchers, led by Professor Tao Liu from the Hong Kong University of Science and Technology, has proposed a new method to detect high-frequency gravitational waves (HFGWs).

This innovative approach could open new doors for studying the early universe and cosmic events by using existing astronomical telescopes in planetary magnetospheres.

Gravitational waves (GWs) are ripples in spacetime caused by powerful cosmic events like phase transitions in the early universe or collisions of black holes.

These waves are incredibly faint and have been detected so far only in low-frequency ranges using a technique called interferometry.

Detecting higher frequency GWs, those above one kilohertz, has been challenging due to technological limitations.

To tackle this problem, Prof. Liu and his team, including postdoctoral fellow Dr. Chen Zhang and Prof. Jing Ren from the Chinese Academy of Sciences, have developed a novel method.

They discovered that when GWs travel through a magnetic field, they can convert into electromagnetic waves, which are easier to detect.

By using the long paths within planetary magnetospheres, like those of Earth or Jupiter, the efficiency of this conversion process is significantly increased.

This means more detectable electromagnetic signals can be generated.

Telescopes with a wide field of view can enhance this detection capability because they can capture the spread-out signals more effectively.

This new method allows a single astronomical telescope to act as a GW detector. Combining multiple telescopes could cover a wide range of HFGW frequencies, from megahertz to an incredibly high 1028 hertz.

This frequency range overlaps with the electromagnetic spectrum used in astronomical observations, including many frequencies that have never been used to detect GWs before.

The research team provided an initial assessment of how sensitive these detectors could be, both for satellite-based detectors in low Earth orbit and for ongoing missions within Jupiter’s magnetosphere.

Their findings were published in Physical Review Letters in March and later highlighted by Nature Astronomy in May, emphasizing the importance of this breakthrough.

The article titled “Planet-sized laboratories offer cosmological insights” praised the potential of this research to revolutionize GW detection technology.

In summary, this new approach of using planetary magnetospheres and existing telescopes to detect high-frequency gravitational waves offers a promising and practical way to explore the universe.

It could help scientists gain deeper insights into the early universe and the nature of cosmic events.

Source: KSR.