Colloquium with Dr. Shao-Kai Jian, assistant professor, Tulane University

Boundary physics plays a crucial role in various disciplines. In this talk, I will focus on the physics of temporal boundaries created by weak measurements. Firstly, I discuss the effect of measurement and postselection on a Luttinger liquid theory. Depending on the Luttinger parameter, measurement effects can be irrelevant, marginal, or relevant, rendering an entanglement transition. When measurement is marginal, a critical state emerges with entanglement entropy exhibiting logarithmic behavior, characterized by a continuous effective central charge. Inspired by these findings, the second part delves into a holographic description of weak measurements. We propose that weak measurement can be modeled by an interface brane, separating different geometries corresponding to the post-measurement and unmeasured states. The effect yields a diverse phase diagram of geometries, including a Python's lunch.