The denser the better: perturbative thermal field theory meets neutron stars

Objetivo

With the recent advent of multimessenger gravitational-wave (GW) astronomy, neutron stars (NSs) have become functioning laboratories of dense Quantum Chromodynamics (QCD) matter, with the physics of the femtometer scale encoded in the macroscopic properties of these extreme astrophysical objects. While milestone results have already been achieved using present-day GW and electromagnetic observatories, the best is yet to come: third-generation GW detectors and other near-future missions are expected to lead to a dramatic increase in the quantity and quality of NS data, including sensitivity to the violent postmerger dynamics.

The forthcoming observational data will provide qualitatively new ways to address several pertinent questions at the interface of astrophysics and fundamental physics, from mapping the high-density corner of the QCD phase diagram to establishing whether deconfined quark matter resides inside massive NSs or emerges during their binary mergers. Progress in this direction is, however, currently hindered by the insufficient accuracy of microphysical inputs to large-scale simulations, rooted in fundamental quantum-field-theoretical issues such as the Sign Problem of lattice QCD.

The aim of the StellarQCD project is to leverage recent methodological breakthroughs in perturbative thermal field theory, pioneered by the PI’s research group, to tackle this challenge and unravel the particle physics of NSs. We will dramatically improve current results for the thermodynamic and transport properties of quark matter at both vanishing and nonzero temperatures, use them to derive accurate model-agnostic predictions for NS matter at all densities, and apply the results in state-of-the-art simulation work on NSs and their binary mergers. Upon combining these advances with future multimessenger data, this work is expected to successfully answer several fundamental puzzles of Nature, including the possible existence of quark-matter cores inside massive NSs.