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Talk by Hiroshi Hiroshi Shinaoka on Multi-scale space-time ansatz for correlation functions of quantum systems
Assistant professor, Saitama University, Japan
03.11.2022 at 10:00
Abstract: Correlation functions of quantum systems are central objects in quantum field theories, which may be defined in high-dimensional space-time domains. The numerical treatment of these objects suffers from the curse of dimensionality, which hinders the application of sophisticated many-body theories to interesting problems. In this talk, we propose a quantum-inspired Multi-Scale Space-Time Ansatz (MSSTA) for correlation functions of quantum systems [1]. The space-time dependence is mapped to auxiliary qubit degrees of freedom describing exponentially different length scales, and the ansatz assumes a separation of length scales. We numerically verify the ansatz for various equilibrium and nonequilibrium systems and demonstrate compression rates of several orders of magnitude for challenging cases. Essential building blocks of diagrammatic equations, such as convolutions or Fourier transforms, are formulated in compressed form. We numerically demonstrate the stability and efficiency of the proposed methods for the Dyson and Bethe-Salpeter equations. MSSTA provides a unified framework for implementing efficient computations of quantum field theories. [1] H. Shinaoka, M. Wallerberger, Y. Murakami, K. Nogaki, R. Sakurai, P. Werner, A. Kauch, arXiv:2210.12984v1, https://arxiv.org/abs/2210.12984
Room A 249