TY - JOUR A1 - Huth, Sabrina A1 - Pang, Peter Tsun Ho A1 - Tews, Ingo A1 - Dietrich, Tim A1 - Le Fèvre, Arnaud A1 - Schwenk, Achim A1 - Trautmann, Wolfgang A1 - Agarwal, Kshitij A1 - Bulla, Mattia A1 - Coughlin, Michael W. A1 - Van den Broeck, Chris T1 - Constraining neutron-star matter with microscopic and macroscopic collisions JF - Nature : the international weekly journal of science N2 - Interpreting high-energy, astrophysical phenomena, such as supernova explosions or neutron-star collisions, requires a robust understanding of matter at supranuclear densities. However, our knowledge about dense matter explored in the cores of neutron stars remains limited. Fortunately, dense matter is not probed only in astrophysical observations, but also in terrestrial heavy-ion collision experiments. Here we use Bayesian inference to combine data from astrophysical multi-messenger observations of neutron stars(1-9) and from heavy-ion collisions of gold nuclei at relativistic energies(10,11) with microscopic nuclear theory calculations(12-17) to improve our understanding of dense matter. We find that the inclusion of heavy-ion collision data indicates an increase in the pressure in dense matter relative to previous analyses, shifting neutron-star radii towards larger values, consistent with recent observations by the Neutron Star Interior Composition Explorer mission(5-8,18). Our findings show that constraints from heavy-ion collision experiments show a remarkable consistency with multi-messenger observations and provide complementary information on nuclear matter at intermediate densities. This work combines nuclear theory, nuclear experiment and astrophysical observations, and shows how joint analyses can shed light on the properties of neutron-rich supranuclear matter over the density range probed in neutron stars. Y1 - 2022 U6 - https://doi.org/10.1038/s41586-022-04750-w SN - 0028-0836 SN - 1476-4687 VL - 606 IS - 7913 SP - 276 EP - 295 PB - Nature Publ. Group CY - London [u.a.] ER - TY - JOUR A1 - Pang, Peter Tsun Ho A1 - Dietrich, Tim A1 - Tews, Ingo A1 - Van Den Broeck, Chris T1 - Parameter estimation for strong phase transitions in supranuclear matter using gravitational-wave astronomy JF - Physical review research N2 - At supranuclear densities, explored in the core of neutron stars, a strong phase transition from hadronic matter to more exotic forms of matter might be present. To test this hypothesis, binary neutron-star mergers offer a unique possibility to probe matter at densities that we cannot create in any existing terrestrial experiment. In this work, we show that, if present, strong phase transitions can have a measurable imprint on the binary neutron-star coalescence and the emitted gravitational-wave signal. We construct a new parametrization of the supranuclear equation of state that allows us to test for the existence of a strong phase transition and extract its characteristic properties purely from the gravitational-wave signal of the inspiraling neutron stars. We test our approach using a Bayesian inference study simulating 600 signals with three different equations of state and find that for current gravitational-wave detector networks already 12 events might be sufficient to verify the presence of a strong phase transition. Finally, we use our methodology to analyze GW170817 and GW190425 but do not find any indication that a strong phase transition is present at densities probed during the inspiral. Y1 - 2020 U6 - https://doi.org/10.1103/PhysRevResearch.2.033514 SN - 2643-1564 VL - 2 IS - 3 PB - American Physical Society CY - College Park ER - TY - JOUR A1 - Kunert, Nina A1 - Pang, Peter T. H. A1 - Tews, Ingo A1 - Coughlin, Michael W. A1 - Dietrich, Tim T1 - Quantifying modeling uncertainties when combining multiple gravitational-wave detections from binary neutron star sources JF - Physical review D N2 - With the increasing sensitivity of gravitational-wave detectors, we expect to observe multiple binary neutron-star systems through gravitational waves in the near future. The combined analysis of these gravitational-wave signals offers the possibility to constrain the neutron-star radius and the equation of state of dense nuclear matter with unprecedented accuracy. However, it is crucial to ensure that uncertainties inherent in the gravitational-wave models will not lead to systematic biases when information from multiple detections is combined. To quantify waveform systematics, we perform an extensive simulation campaign of binary neutron-star sources and analyze them with a set of four different waveform models. For our analysis with 38 simulations, we find that statistical uncertainties in the neutron-star radius decrease to 1250 m (2% at 90% credible interval) but that systematic differences between currently employed waveform models can be twice as large. Hence, it will be essential to ensure that systematic biases will not become dominant in inferences of the neutron-star equation of state when capitalizing on future developments. Y1 - 2022 U6 - https://doi.org/10.1103/PhysRevD.105.L061301 SN - 2470-0010 SN - 2470-0029 VL - 105 IS - 6 PB - American Physical Society CY - College Park ER -