Critics have objected that facts about a black hole’s microstates should not depend upon what we do or do not know about them (e.g. Wüthrich 2017; Dougherty and Callender 2016). Others have suggested that such informational motivations are no longer necessary: contemporary developments in quantum gravity provide a compelling case for black hole thermodynamics without invoking information at all (Wallace 2018, 2019). 

Yet information remains central to high-energy physics. Since Hawking’s (1976) formulation of the black hole information-loss paradox, the fate of information in black hole evaporation has been a persistent concern. In this talk, rather than asking what happens to information when it falls into a black hole, I ask a different question: what role does the concept of information play in contemporary black hole physics? 

I address this question by examining the use of quantum information theory in the groundbreaking works of Page (1993) and Hayden and Preskill (2007). In these approaches, a black hole is treated as a finite-dimensional quantum system whose dynamics can be modelled by a quantum circuit, and whose information-theoretic communication capacities are analysed. I argue that this framework does not replace fundamental physical theory, but provides a higher-level modelling framework for understanding a black hole’s capacity to store, process and transmit information.