Semi-classical bound on Lyapunov exponent and acoustic Hawking radiation in $c=1$ matrix model
Year: 2018
Type: preprint
Abstract: A classical particle motion in an inverse harmonic potential shows the exponential sensitivity of the initial condition, and the Lyapunov exponent $\lambda_L$ is uniquely fixed by the shape of the potential. Hence, if we naively apply the bound on the Lyapunov exponent $\lambda_L \le 2\pi T/ \hbar$, it predicts the existence of the bound on temperature (the lowest temperature) in this system. We consider $N$ non-relativistic free fermions in the inverse harmonic potential ($c=1$ matrix model), and show that thermal radiation with the lowest temperature is induced quantum mechanically similar to the Hawking radiation. This radiation is related to the instability of the fermi sea through the tunneling in the bosonic non-critical string theory, and it is also related to acoustic Hawking radiation by regarding the $N$ fermions as a fermi fluid. Thus the inverse harmonic potential may be regarded as a thermal bath with the lowest temperature and the temperature bound may be saturated.
Source: arXiv (Cornell University)
Author: Takeshi Morita
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2781720602