Video URL

https://pirsa.org/23110084

Generalized LTB spacetime and dust collapse in polymerized spherical symmetric models

Liu, H. (2023). Generalized LTB spacetime and dust collapse in polymerized spherical symmetric models. Perimeter Institute for Theoretical Physics. https://pirsa.org/23110084

Liu, Hongguang. Generalized LTB spacetime and dust collapse in polymerized spherical symmetric models. Perimeter Institute for Theoretical Physics, Nov. 30, 2023, https://pirsa.org/23110084 

          @misc{ scivideos_PIRSA:23110084,
            doi = {10.48660/23110084},
            url = {https://pirsa.org/23110084},
            author = {Liu, Hongguang},
            keywords = {Quantum Gravity},
            language = {en},
            title = {Generalized LTB spacetime and dust collapse in polymerized spherical symmetric models},
            publisher = {Perimeter Institute for Theoretical Physics},
            year = {2023},
            month = {nov},
            note = {PIRSA:23110084 see, \url{https://scivideos.org/index.php/pirsa/23110084}}
          }

Hongguang Liu CPT Marseille

DOI 10.48660/23110084
Source Repository PIRSA
Collection
Talk Type Scientific Series
Subject

Abstract

Recently, models with different properties have been proposed for polymerized dust collapse and regular black holes. To fully understand their properties and differences, we provide a systematic procedure to construct effective polymerized spherically symmetric models encoding holonomy corrections as $1+1$d field theory from effective regular cosmological dynamics or stationary effective metrics. We apply this formalism and consider models that have the following advantages: The effective dynamics can be derived from a class of extended mimetic gravity Lagrangians in 4 dimensions. The models admit a consistent Lemaitre-Tolman-Bondi (LTB) condition, by which the dynamics is completely decoupled along the radial direction in LTB coordinates, trivializing the junction condition in dust collapse. The class of effective dynamics admits a polymerized Birkhoff-like theorem, which leads to a stationary effective metric in the polymerized vacuum. The effective dynamics can reproduce known regular black hole solutions, including Bardeen and Hayward, by a suitable choice of holonomy corrections. As a concrete example, we construct an effective model compatible with the improved dynamics of loop quantum cosmology in the decoupled LTB sector. We compare it with several effective polymerized models recently introduced in the context of loop quantum gravity and gain some new insights into the presence of shocks.

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