论文标题
改性量规不变的爱因斯坦麦克斯韦重力和带有磁性的球形完美流体星的稳定性
Modified Gauge Invariant Einstein Maxwell Gravity and Stability of Spherical perfect fluid Stars with Magnetic Monopoles
论文作者
论文摘要
作为替代性重力模型，我们考虑了具有仪表不变特性的Einstein-Maxwell重力。假定扩展是在空间电磁场之间与Ricci张量之间的定向耦合。我们将看到附加术语在制作紧凑的恒星对象和半径的价值方面的重要性。作为该模型的应用，我们代替了假设的磁性单极的磁场ANSATZ，该磁场的磁场仅具有时间独立的径向分量，并且在物质部分中，我们假设一个完美的流体应力张量。为了获得完美流体恒星紧凑对象的球形对称内部度量，我们解决了tolman-oppenheemer-volkoff方程，其状态方程式为$ p（ρ）=aρ^2 $。使用动力学系统方法，我们研究了箭头图的解决方案的稳定性，该解决方案显示了$ a <0 $（深色星星）和$ a> 0 $（普通可见星）的鞍座（准稳定）和下沉（稳定）。我们还检查了获得解决方案的能量条件，声音和Harrison-Zeldovich-Novikov静态稳定性标准，并确认它们具有稳定状态。
As an alternative gravity model we consider an extended Einstein-Maxwell gravity containing a gauge invariance property. Extension is assumed to be addition of a directional coupling between spatial electromagnetic fields with the Ricci tensor. We will see importance of the additional term in making a compact stellar object and value of its radius. As an application of this model we substitute ansatz of magnetic field of a hypothetical magnetic monopole which has just time independent radial component and for matter part we assume a perfect fluid stress tensor. To obtain spherically symmetric internal metric of the perfect fluid stellar compact object we solve Tolman-Oppenheimer-Volkoff equation with a polytropic form of equation of state as $p(ρ)=aρ^2$. Using dynamical system approach we study stability of the solutions for which arrow diagrams show saddle (quasi stable) for $a<0$ (dark stars) and sink (stable) for $a>0$ (normal visible stars). We check also the energy conditions, speed of sound and Harrison-Zeldovich-Novikov static stability criterion for obtained solution and confirm that they make stable state.
