Orateur
Description
I will discuss three recent model-agnostic studies of dense QCD in neutron stars, combining constraints from nuclear theory, perturbative QCD, and multimessenger observations.
First, I will show that twin-star solutions are strongly disfavored by current data. The few surviving cases require highly fine-tuned EOS behavior and do not support the standard interpretation of twin stars as a robust signature of deconfinement. I will then ask how compact a neutron star can be, showing that the maximum-mass star is also the most compact one and that realistic neutron stars satisfy an approximate upper bound of 1/3, determined by perturbative-QCD constraints.
Finally, I will discuss how dense-matter properties are reflected directly in spacetime geometry, including the appearance of negative Ricci curvature and its relation to the trace anomaly.