We analyze the problem of gravitational collapse considering the matching of an exterior region described by the Vaidya's metric and an interior region described by a spherically symmetric shear-free inhomogeneous geometry sourced by a viscous fluid. We establish initial and final conditions for the process in order that the outcome be a non-singular object, when this is possible, and check how it depends on the fulfillment of the energy conditions. We then apply explicitly the matching procedure to the cases of linear and nonlinear Lagrangians describing electromagnetic fields inside the star, and analyze how the different behaviors for the scale factor of the interior geometry produce singular or nonsingular final stages of the collapse depending on the range where the initial conditions lie.
Temporal evolution of a radiating star via Lie symmetries
在这项工作中,我们提出了第一次的时间演化方程的一般解决方案所产生的匹配共形平坦的内部Vaidya解决方案。这个问题首先由Banerjee等人(A.班纳吉河B. Dutta Choudhury和Bidyut K. Bhui,Phys.Rev.D,40(670)1989),其中他们提供了时间方程的特定解。这个简单的精确解已被广泛用于模拟耗散坍缩,最显着的结果是预测的地平线的回避作为崩溃的进行。我们研究耗散崩溃所产生的动力学通过对称性和奇异性分析的方法获得的一般解决方案。我们表明,我们的模型的崩溃的最终状态是显着不同的广泛使用的线性解决方案。
Inhomogeneous dust collapse in five-dimensional AdS-Chern-Simons gravity
Facultad de Ciencias, Universidad Arturo Prat(阿图罗·普拉特大学理学院);Instituto de Ciencias Exactas y Naturales (ICEN), Universidad Arturo Prat(阿图罗·普拉特大学精确与自然科学研究所);Departamento de Ciencias Exactas, Facultad de Ingeniería, Universidad San Sebastián(圣塞巴斯蒂安大学工程学院精确科学系)
Università degli Studi di Bergamo(贝加莫大学);I.N.F.N.- sezione di Milano(意大利国家核物理研究所米兰分部);National Observatory of Athens(雅典国立天文台);Universidad Católica del Norte(北天主教学大学);University of Science and Technology of China(中国科学技术大学)