EFL: Entropy flux-limited higher-order central scheme for neutron star merger simulations


In 2202.08839 we explore the use of an entropy-based flux-limiting scheme for high-order, convergent simulations of neutron star spacetimes. The scheme effectively tracks the stellar surface and physical shocks using the residual of the entropy equation thus allowing the use of unlimited central flux schemes in regions of smooth flow. We perform the first neutron star merger simulations with such a method and demonstrate up to fourth-order convergence in the gravitational waveform phase. The scheme reduces the phase error up to a factor five when compared to state-of-the-art high-order characteristic schemes and can be employed for producing faithful tidal waveforms for gravitational-wave modelling.


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