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arXiv · 2205.00652

Numerical sign problem and the tempered Lefschetz thimble method

Masafumi Fukuma·Nobuyuki Matsumoto·Yusuke Namekawa
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Abstract

The numerical sign problem is a major obstacle to the quantitative understanding of many important physical systems with first-principles calculations. Typical examples for such systems include finite-density QCD, strongly-correlated electron systems and frustrated spin systems, as well as the real-time dynamics of quantum systems. In this talk, we argue that the "tempered Lefschetz thimble method" (TLTM) [M. Fukuma and N. Umeda, arXiv:1703.00861] and its extension, the "worldvolume tempered Lefschetz thimble method" (WV-TLTM) [M. Fukuma and N. Matsumoto, arXiv:2012.08468], may be a reliable and versatile solution to the sign problem. We demonstrate the effectiveness of the algorithm by exemplifying a successful application of WV-TLTM to the Stephanov model, which is an important toy model of finite-density QCD. We also discuss the computational scaling of WV-TLTM.

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Masafumi Fukuma, Nobuyuki Matsumoto, Yusuke Namekawa. 2022-05-02. Numerical sign problem and the tempered Lefschetz thimble method. https://arxiv.org/abs/2205.00652

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