Binary neutron star mergers in Einstein-scalar-Gauss-Bonnet gravity
Binary neutron star mergers in Einstein-scalar-Gauss-Bonnet gravity
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DOI：
10.1103/physrevd.106.104055
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发表时间：
2022-08
影响因子：
5
通讯作者：
W. East;F. Pretorius
中科院分区：
文献类型：
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作者：
W. East;F. Pretorius
双中子星合并可以导致质量较小的黑洞，相对于其他已知的天体物理通道，它有可能探测到莫迪fi阳离子到广义相对论，与更大质量的致密天体双星相比，广义相对论产生的曲率尺度更小。作为一个典型的例子，我们利用完整的非微扰演化方程的演化研究了移位对称爱因斯坦-标量-高斯-Bonnet引力中的双星中子星合并。我们fi发现，即使在很大的Modifi引力耦合的情况下，对旋涡的影响也很小(正如预期的那样，因为在这个理论中中子星没有标量电荷)。然而，合并后可能会有很强的标量ff效应，包括辐射。当黑洞形成时，它会产生标量电荷，影响环形引力波信号。在合并后寿命较长的残余星持续存在的情况下，我们fi发现，标量辐射的星源能级的振荡类似于黑洞形成的情况。在剩余星中，我们进一步fi发现，在与存在相同质量的黑洞解的最大值相当的耦合值处，标量fifi场存在显著的非线性增强，如果ffi过大，似乎是由于基本方程的双曲性的丧失，导致演化的破裂。
Binary neutron star mergers, which can lead to less massive black holes relative to other known astrophysical channels, have the potential to probe modifications to general relativity that arise at smaller curvature scales compared to more massive compact object binaries. As a representative example of this, here we study binary neutron star mergers in shift-symmetric Einstein-scalar-Gauss-Bonnet gravity using evolutions of the full, non-perturbative evolution equations. We find that the impact on the inspiral is small, even at large values of the modified gravity coupling (as expected, as neutron stars do not have scalar charge in this theory). However, post-merger there can be strong scalar effects, including radiation. When a black hole forms, it develops scalar charge, impacting the ringdown gravitational wave signal. In cases where a longer-lived remnant star persists post-merger, we find that the oscillations of the star source levels of scalar radiation similar to the black hole formation cases. In remnant stars, we further find that at coupling values comparable to the maximum value for which black hole solutions of the same mass exist, there is significant nonlinear enhancement in the scalar field, which if sufficiently large lead to a breakdown in the evolution, seemingly due to loss of hyperbolicity of the underlying equations.