Gravitational shock wave inside a steadily-accreting spherical charged black hole
Gravitational shock wave inside a steadily-accreting spherical charged black hole
复制标题
稳定增长的球形带电黑洞内部的引力冲击波
DOI：
--
复制
发表时间：
2016
期刊：
影响因子：
--
通讯作者：
Ehud Eilon
中科院分区：
文献类型：
--
作者：
Ehud Eilon
我们用数值方法研究了一个吸积中性零流体的四维球对称带电黑洞的内部。Marolf和Ori之前的研究表明，当观察者接近内部视界的出口部分时，他们会遇到有效的冲击波。非线性扰动可以产生有效的重力激波，表现为在落入的观测者极短的固有时间内，区域坐标$r$从内视界值$r_{-}$下降到零。我们考虑了三种不同的情景：a)一个带电黑洞吸积一个（进入的）零流体；B)一个带电黑洞，受到两种零流体的扰动，流入和流出；C)一个带电黑洞，受到一个进入的零流体和一个自引力标量场的扰动。虽然我们在第一种情况下没有观察到任何重力激波的证据，但我们使用进入的类时测地线和零测地线探测到其他两种情况下的激波。激波宽度$ delta au$迅速减小，与新的广义指数定律$ delta ausim e^{-intopkappa_{-} (widdetilde {V}_{f}) dwiddetilde {V}_{f}}$匹配得相当好，其中$ widdetilde {V}_{f}$是入射类时测地线的特定时间参数，$kappa_{-}(widdetilde {V}_{f})$是内视界带电黑洞的广义（Reissner-Nordstr"om类）表面引力。我们还获得了对带电黑洞内部（经典）结构的新见解，这些结构受到两种零流体的扰动，包括存在类空间r=0奇点的有力证据。为了求解从黑洞外区域到$r=0$奇点附近的场方程，我们采用双零坐标有限差分数值编码结合自适应规范法。
We numerically investigate the interior of a four-dimensional, spherically symmetric charged black hole accreting neutral null fluid. Previous study by Marolf and Ori suggested that late infalling observers encounter an effective shock wave as they approach the outgoing portion of the inner horizon. Non-linear perturbations could generate an effective gravitational shock wave, which manifests as a drop of the area coordinate $r$ from inner horizon value $r_{-}$ towards zero in an extremely short proper time duration of the infalling observer. We consider three different scenarios: a) A charged black hole accreting a single (ingoing) null fluid; b) a charged black hole perturbed by two null fluids, ingoing and outgoing; c) a charged black hole perturbed by an ingoing null fluid and a self-gravitating scalar field. While we do not observe any evidence for a gravitational shock in the first case, we detect the shock in the other two, using ingoing timelike and null geodesics. The shock width $Delta au$ decreases rapidly with a fairly good match to a new, generalized exponential law, $Delta ausim e^{-intopkappa_{-} (widetilde{V}_{f})dwidetilde{V}_{f}}$, where $widetilde{V}_{f}$ is a specific timing parameter for the ingoing timelike geodesics and $kappa_{-}(widetilde{V}_{f})$ is a generalized (Reissner-Nordstr"om like) surface gravity of the charged black hole at the inner horizon. We also gain new insight into the inner (classical) structure of a charged black hole perturbed by two null fluids, including strong evidence for the existence of a spacelike $r=0$ singularity. We use a finite-difference numerical code with double-null coordinates combined with an adaptive gauge method in order to solve the field equations from the region outside the black hole down to the vicinity of the $r=0$ singularity.