Fractional Calculus and Applied Analysis ( IF 2.5 ) Pub Date : 2024-11-15 , DOI: 10.1007/s13540-024-00353-6 Fei Gao, Liujie Guo, Xinyi Xie, Hui Zhan
This paper studies the properties of weak solutions to a class of space-time fractional parabolic-elliptic Keller-Segel equations with logistic source terms in \({\mathbb {R}}^{n}\), \(n\ge 2\). The global existence and \(L^{\infty }\)-bound of weak solutions are established. We mainly divide the damping coefficient into two cases: (i) \(b>1-\frac{\alpha }{n}\), for any initial value and birth rate; (ii) \(0<b\le 1-\frac{\alpha }{n}\), for small initial value and small birth rate. The existence result is obtained by verifying the existence of a solution to the constructed regularization equation and incorporate the generalized compactness criterion of time fractional partial differential equation. At the same time, we get the \(L^{\infty }\)-bound of weak solutions by establishing the fractional differential inequality and using the Moser iterative method. Furthermore, we prove the uniqueness of weak solutions by using the hyper-contractive estimates when the damping coefficient is strong.
中文翻译:
分数时空 Keller-Segel 系统的全局存在、唯一性和 $$L^{\infty }$$ -bound 的弱解
本文研究了一类时空分数阶抛物线-椭圆 Keller-Segel 方程的弱解的性质,其逻辑源项在 \({\mathbb {R}}^{n}\), \(n\ge 2\) 中。弱解的全局存在和 \(L^{\infty }\) 界已建立。我们主要将阻尼系数分为两种情况:(i) \(b>1-\frac{\alpha }{n}\),对于任何初始值和出生率;(ii) \(0<b\le 1-\frac{\alpha }{n}\),初始值小,出生率小。通过验证所构建的正则化方程的解的存在性,并结合时间分数偏微分方程的广义紧凑性准则,得到存在性结果。同时,我们通过建立分数阶微分不等式并使用 Moser 迭代方法得到弱解的 \(L^{\infty }\) 界。此外,当阻尼系数较强时,我们通过使用超收缩估计来证明弱解的唯一性。