# Tiny universes from ensembles of open quantum systems

### APA

Shandera, S. (2024). Tiny universes from ensembles of open quantum systems. Perimeter Institute. https://pirsa.org/24030118

### MLA

Shandera, Sarah. Tiny universes from ensembles of open quantum systems. Perimeter Institute, Mar. 20, 2024, https://pirsa.org/24030118

### BibTex

@misc{ pirsa_PIRSA:24030118, doi = {10.48660/24030118}, url = {https://pirsa.org/24030118}, author = {Shandera, Sarah}, keywords = {Other}, language = {en}, title = {Tiny universes from ensembles of open quantum systems}, publisher = {Perimeter Institute}, year = {2024}, month = {mar}, note = {PIRSA:24030118 see, \url{https://pirsa.org}} }

Sarah Shandera Pennsylvania State University

## Abstract

Gravity creates space-time boundaries that limit observables without limiting the flow of energy and information. This means that quantum systems in cosmology are often open systems: to describe them we must include the effects of interaction with an unobservable environment. In many cosmological settings, different observers see different parts of the spacetime; the ensemble of the open systems for each observer makes up the full cosmology. In this talk I will introduce a class of out-of-equilibrium quantum systems constructed to mimic some key features of cosmology and demonstrate the utility of treating the full system as an ensemble of open systems. I will use these models to illustrate the possible connections between cosmological open quantum systems and thermodynamics, as well as open-systems-inspired ways to think about locality.

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