Aging is a (log-)Poisson Process, not a Renewal Process¹

Aging is a ubiquitous relaxation dynamic in disordered materials. It ensues after a rapid quench from an equilibrium ``fluid'' state into a non-equilibrium, history-dependent jammed state. We propose a physically motivated description that contrasts sharply with the trap model<sup>2</sup> or a continuous-time random walk (CTRW) with broadly distributed trapping times commonly used to fit aging data.<sup>3</sup> A renewal process like CTRW proves irreconcilable with the log-Poisson statistic exhibited, for example, by jammed colloids as well as by disordered magnets. A log-Poisson process is characteristic of the intermittent and decelerating dynamics of jammed matter usually activated by record-breaking fluctuations (``quakes''). We show that such a record dynamics (RD) provides a universal model for aging, physically grounded in generic features of free-energy landscapes of disordered systems.<sup>4

1</sup>Phys. Rev. E 98, 020602 (2018) [https://arxiv.org/abs/1803.06580]
²J. Phys. I France 2, 1705 (1992)
³Phys. Rev. X 4, 011028 (2014) [https://arxiv.org/abs/1310.1058]
⁴EPL 116 (2016) 38003 [https://arxiv.org/abs/1608.03869]