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arXiv · 1407.0209

Random geometry and the Kardar-Parisi-Zhang universality class

Silvia N. Santalla·Javier Rodriguez-Laguna·Tom LaGatta·Rodolfo Cuerno
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Abstract

We consider a model of a quenched disordered geometry in which a random metric is defined on ${\mathbb R}^2$, which is flat on average and presents short-range correlations. We focus on the statistical properties of balls and geodesics, i.e., circles and straight lines. We show numerically that the roughness of a ball of radius $R$ scales as $R^\chi$, with a fluctuation exponent $\chi \simeq 1/3$, while the lateral spread of the minimizing geodesic between two points at a distance $L$ grows as $L^\xi$, with wandering exponent value $\xi\simeq 2/3$. Results on related first-passage percolation (FPP) problems lead us to postulate that the statistics of balls in these random metrics belong to the Kardar-Parisi-Zhang (KPZ) universality class of surface kinetic roughening, with $\xi$ and $\chi$ relating to critical exponents characterizing a corresponding interface growth process. Moreover, we check that the one-point and two-point correlators converge to the behavior expected for the Airy-2 process characterized by the Tracy-Widom (TW) probability distribution function of the largest eigenvalue of large random matrices in the Gaussian unitary ensemble (GUE). Nevertheless extreme-value statistics of ball coordinates are given by the TW distribution associated with random matrices in the Gaussian orthogonal ensemble. Furthermore, we also find TW-GUE statistics with good accuracy in arrival times.

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Silvia N. Santalla, Javier Rodriguez-Laguna, Tom LaGatta, Rodolfo Cuerno. 2014-07-01. Random geometry and the Kardar-Parisi-Zhang universality class. https://doi.org/10.1088/1367-2630/17/3/033018

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