Straight Out of the Big Bang: New Type of Gravitational Wave Detector to Find Tennis Ball-Sized Black Holes - SciTechDaily

A new type of gravitational wave detector to find tennis ball-sized black holes straight out of the Big Bang.

“Detecting primordial black holes opens up new perspectives to understand the origin of the Universe, because these still hypothetical black holes are supposed to have formed just a few tiny fractions of a second after the Big Bang.

The idea was to combine the UNamur expertise in the field of gravitational wave antennas, an idea patented by Professor Fuzfa in 2018 and studied by Nicolas Herman as part of his doctorate, with that of ULB in the booming field of primordial black holes, in which Professor Clesse is one of the central players.

They have just developed an application of this type of detector in order to observe “small” primordial black holes.

“To this day, these primordial black holes are still hypothetical, because it is difficult to make the difference between a black hole resulting from the implosion of a star core and a primordial black hole.

Being able to observe smaller black holes, the mass of a planet but a few centimeters in size, would make the difference,” the team of researchers says.

They carry on: “We are offering experimenters a device that could detect them, by capturing the gravitational waves they emit when merging and which are of much higher frequencies than those currently available.”.

A gravitational wave “antenna,” composed of a specific metal cavity and suitably immersed in a strong external magnetic field.

When the gravitational wave goes through the magnetic field, it generates electromagnetic waves in the cavity.

This type of device, just a few meters in size, would be enough to detect fusions of primordial small black holes millions of light years from Earth.

The detection method makes it sensitive to very high frequency gravitational waves (in the order of 100 MHz, compared to 10-1000 Hz for LIGO / Virgo / Kagra), which are not produced by ordinary astrophysical sources such as fusions, neutron stars or stellar black holes.

On the other hand, it is ideal for the detection of small black holes, the mass of a planet and its size goes from a small ball to a tennis ball.

In addition to primordial black holes, this type of detector could also directly observe the gravitational waves emitted at the time of the Big Bang, and thus probe physics at much higher energies than the ones achieved in particle accelerators.