String Theory Journal Club

In this talk, I will start with an introduction of the holographic defect model, which is a domain wall geometry with a one-dimensional lower tensile AdS brane. By considering the boundary graviton scattering process in AdS_3, you will see that the brane tension is dual to the energy transport coefficients on the CFT side, instead of the boundary entropy which has been commonly believed. In the second part, I will move to the holographic consideration of a quantity from quantum information theory which is called quantum complexity. The same holographic defect model will be used to quest for the universality of the two holographic conjectures “Complexity = Volume” and “Complexity = Action”. Though a definite answer can not be reached in the current scope, I will make some comments based on our preliminary field theory complexity considerations.