Thermodynamics and weak cosmic censorship conjecture of an AdS black hole with a monopole in the extended phase space

The first law of black hole thermodynamics has been shown to be valid in the extended phase space. However, the second law and the weak cosmic censorship conjecture have not been investigated extensively. We investigate the laws of thermodynamics and the weak cosmic censorship conjecture of an AdS black hole with a global monopole in the extended phase space in the case of charged particle absorption. It is shown that the first law of thermodynamics is valid, while the second law is violated for the extremal and near-extremal black holes. Moreover, we find that the weak cosmic censorship conjecture is valid only for the extremal black hole, and that it can be violated for the near-extremal black holes, which is different from the previous results. * Supported by National Natural Science Foundation of China (11875095) and Basic Research Project of Science and Technology Committee of Chongqing (cstc2018jcyjA2480)