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arXiv · 2202.03225

Time-correlation functions for odd Langevin systems

Kento Yasuda·Kenta Ishimoto·Akira Kobayashi·Li-Shing Lin·Isamu Sou·Yuto Hosaka·Shigeyuki Komura
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Abstract

We investigate the statistical properties of fluctuations in active systems that are governed by non-symmetric responses. Both an underdamped Langevin system with an odd resistance tensor and an overdamped Langevin system with an odd elastic tensor are studied. For a system in thermal equilibrium, the time-correlation functions should satisfy time-reversal symmetry and the anti-symmetric parts of the correlation functions should vanish. For the odd Langevin systems, however, we find that the anti-symmetric parts of the time-correlation functions can exist and that they are proportional to either the odd resistance coefficient or the odd elastic constant. This means that the time-reversal invariance of the correlation functions is broken due to the presence of odd responses in active systems. Using the short-time asymptotic expressions of the time-correlation functions, one can estimate an odd elastic constant of an active material such as an enzyme or a motor protein.

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Kento Yasuda, Kenta Ishimoto, Akira Kobayashi, Li-Shing Lin, Isamu Sou, Yuto Hosaka, Shigeyuki Komura. 2022-02-07. Time-correlation functions for odd Langevin systems. https://doi.org/10.1063/5.0095969

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