论文标题
具有乘法α稳定lévy噪声的随机逻辑生长模型的平均退出时间和逃生概率
Mean Exit Time and Escape Probability for the Stochastic Logistic Growth Model with Multiplicative α-Stable Lévy Noise
论文作者
论文摘要
在本文中,我们制定了由白噪声和非高斯噪声驱动的随机逻辑鱼生长模型。我们将研究重点放在平均灭绝时间,逃避概率以测量噪声诱导的灭绝概率以及鱼类种群x(t)的fokker-planck方程。在高斯情况下,这些数量满足局部偏微分方程,而在非高斯案例中,它们满足了非局部偏微分方程。在讨论存在,独特性和稳定性之后,我们计算了这些方程解的数值近似值。对于每个噪声模型,我们将平均灭绝时间的行为和Fokker-Planck方程的解决方案比较作为增长率R,携带能力K,高斯噪声$λ$,噪声强度$σ$和稳定性指数$α$α$不同。如果$λ<{\ sqrt2} $,则来自右边界间隔(0,1)的MET是有限的。对于$λ> {\ sqrt2} $,在此边界处(0,1)的MET是无限的。较大的稳定指数$α$不太可能导致鱼类种群的灭绝。
In this paper, we formulate a stochastic logistic fish growth model driven by both white noise and non-Gaussian noise. We focus our study on the mean time to extinction, escape probability to measure the noise-induced extinction probability and the Fokker-Planck equation for fish population X(t). In the Gaussian case, these quantities satisfy local partial differential equations while in the non-Gaussian case, they satisfy nonlocal partial differential equations. Following a discussion of existence, uniqueness, and stability, we calculate numerical approximations of the solutions of those equations. For each noise model we then compare the behaviors of the mean time to extinction and the solution of the Fokker-Planck equation as growth rate r, carrying capacity K, the intensity of Gaussian noise $λ$, noise intensity $σ$ and stability index $α$ vary. The MET from the interval (0,1) at the right boundary is finite if $λ <{\sqrt2}$. For $λ > {\sqrt2}$, the MET from (0,1) at this boundary is infinite. A larger stability index $α$ is less likely to lead to the extinction of the fish population.