University of Coimbra research highlighted in 'Scientific American'
The study "Collapsing Domain Wall Networks: Impact on Pulsar Timing Arrays and Primordial Black Holes", published in the journal 'Scientific American', concluded that the collapse of cosmological domain wall networks leads to the formation of primordial black holes.
An international study involving Ricardo Zambujal Ferreira, a researcher at the Centre for Physics of the University of Coimbra (CFisUC) and the Department of Physics of the Faculty of Sciences and Technology (FCTUC), has been highlighted in the journal Scientific American.
The research "Collapsing Domain Wall Networks: Impact on Pulsar Timing Arrays and Primordial Black Holes", concludes that the collapse of cosmological domain wall networks leads to the formation of primordial black holes.
"This work studied the evolution and collapse of the so-called domain wall network, a kind of wall-like labyrinthine structure that wandered through the primordial universe," explains Ricardo Zambujal Ferreira.
"We found two interesting patterns. On the one hand, if these networks collapsed at the same time as the cosmic structures of the early universe formed, they could generate gravitational waves, which might explain the recent signals detected by observatories monitoring millisecond pulsars (neutron stars that rotate hundreds of times per second). Additionally, this collapse could lead to the formation of primordial black holes, which might be detectable in the near future," says the author of the scientific article.
"On the other hand," he adds, "if domain-wall annihilation occurred even earlier in the evolution of the Universe, this would lead to a modern surplus of asteroid-mass primordial black holes, sufficient to account for dark matter. In this case, the gravitational waves produced would have a complementary signal around the Hertz frequency, which future observatories could also detect."
According to the physicist, the central theme of the discussion is the existence of a cosmological network of domain walls in the primordial universe. "This network is predicted by various extensions of the Standard Model of particle physics, which essentially try to explain some of the open questions in modern physics. Detecting domain walls is therefore a proxy way of testing fundamental physics," he says.
The scientific article Collapsing Domain Wall Networks: Impact on Pulsar Timing Arrays and Primordial Black Holes is available here.