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  - 
TY  - JOUR
A1  - Samajdar, Anuradha
A1  - Dietrich, Tim
T1  - Constructing Love-Q relations with gravitational wave detections
JF  - Physical review : D, Particles, fields, gravitation, and cosmology
N2  - Quasiuniversal relations between the tidal deformability and the quadrupole moment of neutron stars are predicted by theoretical computations, but have not been measured experimentally. We simulate 120 binary neutron star sources and find that Advanced LIGO and Advanced Virgo at design sensitivity could find possible deviations from predicted relations if the neutron stars are highly spinning. A network of envisaged third generation detectors will even allow extracting such relations, providing new tests of general relativity and nuclear physics predictions.
Y1  - 2020
U6  - https://doi.org/10.1103/PhysRevD.101.124014
SN  - 1550-7998
SN  - 1550-2368
VL  - 101
IS  - 12
PB  - American Physical Society
CY  - College Park
ER  -