TY  - JOUR
A1  - Poudel, Amit
A1  - Tichy, Wolfgang
A1  - Brügmann, Bernd
A1  - Dietrich, Tim
T1  - Increasing the accuracy of binary neutron star simulations with an improved vacuum treatment
JF  - Physical review : D, Particles, fields, gravitation, and cosmology
N2  - Numerical-relativity simulations are essential for studying the last stages of the binary neutron star coalescence. Unfortunately, for stable simulations there is the need to add an artificial low-density atmosphere. Here we discuss a new framework in which we can effectively set the density surrounding the neutron stars to zero to ensure a more accurate simulation. We test our method with a number of single star test cases and for an equal-mass binary neutron star simulation. While the bulk motion of the system is not influenced, and hence there is no improvement with respect to the emitted gravitational-wave signal, we find that the new approach is superior with respect to mass conservation and it allows a much better tracking of outward moving material. This will allow a more accurate simulation of the ejected material and supports the interpretation of present and future multimessenger observations with more accurate numerical-relativity simulations.
Y1  - 2020
U6  - https://doi.org/10.1103/PhysRevD.102.104014
SN  - 2470-0010
SN  - 2470-0029
VL  - 102
IS  - 10
PB  - American Physical Society
CY  - College Park
ER  -