论文标题

与随机重置的自相似高斯过程的大偏差的凝结过渡

Condensation transition in large deviations of self-similar Gaussian processes with stochastic resetting

论文作者

Smith, Naftali R., Majumdar, Satya N.

论文摘要

我们研究了区域$ a(t)= \ int_0^t x(τ)\,dτ$在自相似的高斯过程(SGP)$ x(τ)$的情况下,带有hurst指数$ h> 0 $(例如,标准的或标准的棕色运动或随机的动作,或随机的流程,或随机的过程),或者是$ $ $ $ $ $ $ r $ r $ r $ r $ r $ r $。 $ a(t)$ scale的典型波动为$ \ sim \ sqrt {t} $对于大$ t $,在此规模上,分布是高斯,正如人们从中央限制定理中期望的那样。在这里,我们的主要重点是$ a(t)$的非典型波动。在长期限制$ t \ to \ infty $中,我们发现该区域的完整分布采用$ p_ {r} \ left(a | t \ right)\ sim \ sim \ exp \ left [-t^αφ\ left(a/t^ββ\ weft(a/t^β\ right)\ right] (2H+3)/(4H+4)$在中等大波动方面,以及不同的异常缩放表格$ p_ {r} \ left(a | t \ right)\ sim \ sim \ sim \ sim \ exp \ left [-t病\ left(a/t \ left(a/t^{a/t+weft(a/t)关联的费率功能$φ(y)$和$ψ(w)$取决于$ h $,并且完全找到。值得注意的是,$φ(y)$具有奇异性,我们将其解释为一阶动力冷凝转换,而$ψ(w)$表现出二阶动力学相变,上面的重置事件的数量将停止。 $ y = 0 $周围的$φ(y)$的抛物线行为正确地描述了$ a(t)$的典型高斯波动。尽管有这些异常的尺度,我们发现分布的所有累积物$ p_ {r} \ left(a | t \ right)$及时线性地生长,$ \ langle a^n \ rangle_c \ rangle_c \ oft c_n \ c_n \ c_n \,t $,在长期限制中。对于重置Brownian运动的情况(对应于$ H = 1/2 $),我们开发了一个递归方案来计算系数$ C_N $,并使用它来计算前6个非散布累积物。

We study the fluctuations of the area $A(t)= \int_0^t x(τ)\, dτ$ under a self-similar Gaussian process (SGP) $x(τ)$ with Hurst exponent $H>0$ (e.g., standard or fractional Brownian motion, or the random acceleration process) that stochastically resets to the origin at rate $r$. Typical fluctuations of $A(t)$ scale as $\sim \sqrt{t}$ for large $t$ and on this scale the distribution is Gaussian, as one would expect from the central limit theorem. Here our main focus is on atypically large fluctuations of $A(t)$. In the long-time limit $t\to\infty$, we find that the full distribution of the area takes the form $P_{r}\left(A|t\right)\sim\exp\left[-t^αΦ\left(A/t^β\right)\right]$ with anomalous exponents $α=1/(2H+2)$ and $β= (2H+3)/(4H+4)$ in the regime of moderately large fluctuations, and a different anomalous scaling form $P_{r}\left(A|t\right)\sim\exp\left[-tΨ\left(A/t^{\left(2H+3\right)/2}\right)\right]$ in the regime of very large fluctuations. The associated rate functions $Φ(y)$ and $Ψ(w)$ depend on $H$ and are found exactly. Remarkably, $Φ(y)$ has a singularity that we interpret as a first-order dynamical condensation transition, while $Ψ(w)$ exhibits a second-order dynamical phase transition above which the number of resetting events ceases to be extensive. The parabolic behavior of $Φ(y)$ around the origin $y=0$ correctly describes the typical, Gaussian fluctuations of $A(t)$. Despite these anomalous scalings, we find that all of the cumulants of the distribution $P_{r}\left(A|t\right)$ grow linearly in time, $\langle A^n\rangle_c\approx c_n \, t$, in the long-time limit. For the case of reset Brownian motion (corresponding to $H=1/2$), we develop a recursive scheme to calculate the coefficients $c_n$ exactly and use it to calculate the first 6 nonvanishing cumulants.

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