Building an Equation of State Density Ladder

The confluence of major theoretical, experimental, and observational advances are providing a unique perspective on the equation state dense neutron-rich matter—particularly its symmetry energy—and imprint mass-radius relation for neutron stars. In this contribution, we organize these developments in an density ladder. Of particular relevance to discussion impact various rungs identification possible discrepancies among methods. A preliminary analysis identifies tension between laboratory measurements gravitational-wave detections that could indicate emergence phase transition stellar core.