2025/01/29 by Aapeli Kärkkäinen, Kärkkäinen, A., Pablo Navarrete +9 · 5 citations
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #Particle physics theoretical and experimental studies
paper · pdf · doi:10.48550/arxiv.2501.17921
openalex publication_date 2025/01/29 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Knowledge of the pressure of cold and dense quark matter (QM) is known to significantly constrain the equation of state of neutron-star matter, a quantity playing a key role in deciphering the stars' internal structure. In this work, we make important progress towards determining the last unknown contribution to the pressure at Next-to-Next-to-Next-to-Leading Order (N3LO) in the strong coupling constant αs, available through the sum of all four-loop vacuum diagrams of dense Quantum Chromodynamics. We demonstrate the cancellation of both the covariant gauge parameter and all infrared (IR) divergences in the sum, showcasing the effective-field-theory paradigm in action. For the remaining IR-finite four-loop integrals, we demonstrate the efficacy of the dense Loop Tree Duality method -- a novel numerical framework for multiloop calculations in thermal field theory. Together, our results show that completing the N3LO pressure of cold QM is no longer merely possible but for the first time concretely within reach.