论文标题

4D爱因斯坦 - 加斯 - 鲍尼特理论中的球形引力崩溃

Spherical Gravitational Collapse in 4D Einstein-Gauss-Bonnet theory

论文作者

Jaryal, Suresh C., Chatterjee, Ayan

论文摘要

在本文中,我们研究了无与伦比的无与伦比的无均匀压力物质的球形引力崩溃,该物质是$ n \ rightarrow4 $ d的爱因斯坦 - 加斯 - 托内特重力的极限。塌陷导致一个黑洞或巨大的裸露奇异性,具体取决于被困的表面的形成时间。更确切地说,Horizo​​n的形成及其时间开发受高斯式耦合$(λ)$的相对强度和MISNER-SHARP质量函数$ F(R,T)$ f(r,t)$ f(r,t)的控制。我们发现,如果最初的Cauchy Hyperface上没有被困的表面,而$ f(r,t)<2 \sqrtλ$,则中央奇异性是巨大而赤裸的。当这种不平等均等或逆转时,中心奇异性总是会被拓扑的间距/时型球形略微捕获的表面$ s^{2} \ times \ times \ mathbb {r} $,最终在Equilibrim处变得无效,并与活动视界无关。这些结论是针对承认不同初始速度条件的广泛质量谱的验证。因此,我们的结果意味着$ 4 $ D EINSTEIN-GAUSS-BONNET通常违反了宇宙审查的结合。还讨论了从时空奇异性的因果信号的可见性的角度来看,这种违规行为的进一步含义。

In this paper, we study spherical gravitational collapse of inhomogeneous pressureless matter in a well-defined $n \rightarrow4$d limit of the Einstein-Gauss-Bonnet gravity. The collapse leads to either a black hole or a massive naked singularity depending on time of formation of trapped surfaces. More precisely, horizon formation and its time development is controlled by relative strengths of the Gauss-Bonnet coupling $(λ)$ and the Misner-Sharp mass function $F(r,t)$ of collapsing sphere. We find that, if there is no trapped surfaces on the initial Cauchy hypersurface and $F(r,t)< 2\sqrtλ$, the central singularity is massive and naked. When this inequality is equalised or reversed, the central singularity is always censored by spacelike/timelike spherical marginally trapped surface of topology $S^{2}\times \mathbb{R}$, which eventually becomes null and coincides with the event horizon at equilibrium. These conclusions are verified for a wide class of mass profiles admitting different initial velocity conditions. Hence, our result implies that the $4$d Einstein-Gauss-Bonnet generically violates the cosmic censorship conjuncture. Further implications of this violation from the perspective of visibility of causal signals from the spacetime singularity are also discussed.

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