Open Quantum Systems Research for Cosmology

This award funds the research activities of Professor Sarah Shandera at Penn State University. There are still many puzzles in understanding the origin, content, and evolution of the universe. At a fundamental level, the theory of the universe must be quantum-mechanical and must be able to describe what any one observer sees. Such a description is challenging when interactions enable quantum information to move back and forth between observable and unobservable regions. Such models must therefore be capable of describing what are called "open quantum systems". Modeling such systems may play a key role in understanding the properties of the very early universe. As part of her research, Professor Shandera will apply our understanding of open quantum systems to cosmological problems. This work serves the national interest by promoting the progress of science within the arenas of quantum science and studies of the universe. Cosmology's quest to understand the universe also provides an inspiring context in which to communicate science to a broad range of audiences. As part of this work, Professor Shandera will meet with citizen groups and undergraduate students in a variety of venues that promote conversation and two-way engagement. She will also continue to incorporate research insights into an active-learning undergraduate quantum mechanics sequence. Finally, Professor Shandera will support the training of graduate students in order to grow the network of researchers in this area. More technically, Professor Shandera will study how the dynamics of open quantum systems changes when degrees of freedom move from system to environment, and when symmetry-breaking interactions occur in the environment of the open system. Cosmological open systems, including those that arise in the era of primordial inflation, tend to be quite complex and often cannot be accurately treated by Markovian or perturbative assumptions. Professor Shandera will study non-linear interactions typical in theories for cosmology beyond the standard model and use dynamical maps rather than master equations to study exact dynamics. She will explore systems with emergent, local interaction structures and out-of-equilibrium dynamics, modeling the observed rich thermodynamic structure of the universe. It is expected that this open systems and thermodynamics-based approach will provide a new perspective on the space of viable models for the primordial universe.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.