Seminar: Dr. Teerthal Patel
- Speaker: Dr. Teerthal Patel
- Date: Wed, August 26 14:00- JST (UTC+9) C103
- Title: Robust 3+1D simulations of BDNK causal relativistic hydrodynamics
Abstract:
Relativistic viscous hydrodynamics provides the standard effective description of the quark–gluon plasma (QGP) produced in ultrarelativistic heavy-ion collisions. Most current simulations are based on Israel–Stewart (IS)–type theories, whose formulation introduces additional dynamical fields and whose causal properties have long been the subject of theoretical discussion. In this talk, I will present recent progress on the Bemfica–Disconzi–Noronha–Kovtun (BDNK) formulation of relativistic viscous hydrodynamics, a first-order gradient expansion theory with well-defined causality and stability properties.
I will discuss our numerical implementation, which enables stable and accurate 3+1D simulations of BDNK hydrodynamics in general spacetimes. We have studied canonical benchmark problems related to heavy-ion collisions as well as simple accretion flows in Kerr spacetimes. Benchmark tests include convergence studies against semi-analytical solutions for conformal Bjorken and Gubser flows, as well as simulations initialized with TRENTo profiles using a tabulated QCD equation of state. I will also discuss the challenges of mapping initial conditions between Israel–Stewart and BDNK formulations, present the simplified approach adopted in this work, and outline ongoing efforts toward a more general initialization procedure that would enable direct comparisons between the two frameworks and facilitate the adoption of BDNK within existing heavy-ion workflows.
Finally, I will briefly discuss ongoing work on more efficient BDNK formulations, recent developments in nonlinear causality and stability conditions for Israel–Stewart theory, and future directions including adaptive mesh refinement and relativistic magnetohydrodynamics.