UiS researcher Aleksi Kurkela has been awarded 12 million kroner from the Research Council of Norway for a new project investigating the fundamental forces acting inside neutron stars — some of the most extreme objects in the universe.
The five-year project, Quantum Chromodynamics in Neutron-Star Cores (CoreQCD), aims to answer one of the biggest open questions in nuclear astrophysics: how matter behaves under the extreme pressures and densities found deep inside neutron stars.
Kurkela studies how ordinary matter behaves under extraordinary conditions. His research focuses on quantum chromodynamics (QCD), the branch of particle physics that describes the strong nuclear force — the force that binds quarks and gluons together inside protons and neutrons.
Extreme conditions
“There are very few places in the universe where we can study matter under such extreme conditions,” says Kurkela. “Neutron stars allow us to explore physics that cannot be recreated anywhere else.”
While quarks are normally confined inside protons and neutrons, physicists believe that under sufficiently high densities matter may transition into an exotic state known as quark matter. One of the project’s central goals is to determine whether this form of matter exists in the cores of massive neutron stars.
Neutron stars are extraordinarily dense remnants of collapsed stars. They can pack more mass than our Sun into a sphere only about 25 kilometres across. These extreme conditions make neutron stars unique laboratories for studying the strong nuclear force and the behaviour of matter at the highest densities known in the universe.
New research possibilities
The project combines advanced theoretical calculations with observations from modern astronomy, including gravitational-wave measurements from neutron-star mergers. Recent breakthroughs in multimessenger astronomy — combining gravitational waves, X-ray observations, and electromagnetic signals — have opened entirely new possibilities for studying dense matter.
CoreQCD will develop new methods for connecting first-principles calculations in QCD with astrophysical observations. The project also aims to identify observable signatures of quark matter in neutron-star mergers, helping scientists interpret future data from next-generation gravitational-wave observatories such as the Einstein Telescope and Cosmic Explorer.
“We are entering a new era where observations of neutron stars can directly test fundamental theories of matter,” says Kurkela.
“It is incredibly exciting that we may soon be able to determine what the cores of neutron stars are actually made of.”
The project will begin in autumn 2026 and includes funding for two new research positions: a doctoral fellow and a postdoctoral researcher.