论文标题
旋转和空间扭曲的无膨胀动力恒星不存在
Non-existence of expansion-free dynamical stars with rotation and spatial twist
论文作者
论文摘要
扩展了同一作者先前的作品，我们研究了具有非零空间扭曲和旋转的无膨胀动力恒星的存在，并表明这种恒星不存在。首先，结果表明，不存在零扭转的无旋转膨胀动力恒星。这是由于这样的恒星无法辐射并且没有剪切的事实，在这种情况下，能量密度$ρ$是独立的。其次，我们证明，具有非零空间扭曲的非旋转无膨胀动力恒星也不存在，因为必须违反强能量条件，即$ρ+3p <0 $，或者恒星必须无剪切，在这种情况下，恒星是静态的（$θ=ω=ω=σ= 0 $）。最后，如果我们坚持认为旋转和空间扭曲是同时非零的，那么在这种情况下，恒星不能无剪切，我们获得了$ ϕ $的二次多项式方程，而没有真实的解决方案。因此，这种恒星不可能存在。
Extending a previous work by the same authors, we investigate the existence of expansion-free dynamical stars with non-zero spatial twist and rotation and show that such stars cannot exist. Firstly, it is shown that a rotating expansion-free dynamical star with zero twist cannot exist. This is due to the fact that such stars cannot radiate and they are shear-free, in which case the energy density $ρ$ is time independent. Secondly, we prove that a non-rotating expansion-free dynamical star with non-zero spatial twist also cannot exist, as either the strong energy condition must be violated, i.e. $ρ+3p<0$, or the star must be shear-free in which case the star is static ($Θ=Ω=Σ=0$). Finally, if we insist that the rotation and spatial twist are simultaneously non-zero, then the star cannot be shear-free in which case we obtain a quadratic polynomial equation in $ϕ$ and $Σ$ with no real solutions. Therefore such stars cannot exist.
