Beijing Institute of Mathematical Sciences and Applications

Kazem Bitaghsir Fadafan

Wednesday, August 27, 2025 10:00 AM - 11:00 AM

A7-201

Zoom 242 742 6089 (BIMSA)

The nature of quantum chromodynamics (QCD) at high density and temperature remains one of the most challenging problems in theoretical physics, with direct implications for understanding neutron star structure and the signals from their merger, including gravitational waves. In this talk, we explore the phase diagram of dense QCD matter using holographic methods. We first introduce top-down and bottom-up approaches to model strongly interacting quark matter. We mention the V-QCD and Sakai-Sugimoto models but we focus on the D3-D7 brane construction, which introduces fundamental degrees of freedom into N=4 Super Yang-Mills theory. Our model predicts a first-order chiral transition and an intermediate-density deconfined phase with massive quarks. We also include a holographic description of colour superconductivity phase and study the resulting equation of state. When applied to neutron stars, this phase yields mass-radius relations compatible with GW170817 constraints, suggesting quark matter cores may exist in massive compact stars. This talk bridges holographic QCD modeling, astrophysical observations, and the extreme-density regime probed by gravitational-wave astronomy.