论文标题
像黑洞一样，buchdahl星星不能极端化
Like Black holes, Buchdahl stars cannot be extremalized
论文作者
论文摘要
很久以前就在\ cite {dadhich97}中显示了一个非超级黑洞不能通过测试粒子绝热积聚转化为极端。 Buchdahl星是没有地平线的最紧凑的对象，由$φ（R）= 4/9 $定义，而Black Hole by $φ（R）= 1/2 $。这里$φ（r）$是粒子经历的重力潜力，径向落在静态和轴向旋转对象上。在此简短的说法中，我们检查了布赫德尔恒星的极端化问题，并表明相同的结果与黑洞相同。也就是说，非超级buchdahl恒星不能通过测试粒子积聚极端。此外，由于BS的极端限制为$> 1美元，因此可以通过中性和无旋转积聚来促进极端黑洞的形成。这也许是它们可以形成的唯一途径。
It was shown long back in \cite{Dadhich97} that a non-extremal black hole cannot be converted into an extremal one by test particle adiabatic accretion. The Buchdahl star is the most compact object without horizon and is defined by $Φ(R) = 4/9$, while black hole by $Φ(R) = 1/2$. Here $Φ(R)$ is the gravitational potential experienced by a particle, radially falling for static and axially for the rotating object. In this short note we examine the question of extremalization of the Buchdhal star and show that the same result holds good as for the black hole. That is, a non-extremal Buchdahl star cannot be extremalized by test particle accretion. Further since extremal limit for BS is $>1$, it could facilitate formation of extremal black holes by neutral and spinless accretion. That is perhaps the only way they could be formed.
