Well-posedness of mild solutions to the drift-diffusion and the vorticity equations in amalgam spaces

We consider the Cauchy problem of the drift-diffusion and the vorticity equations. Both equations involve the Poisson equation and a nonlocal effect of the Green's function influences the solution to the problem. In this paper, we study the well-posedness of the drift-diffusion and the vorticity equations by using amalgam spaces of Lebesgue spaces. Moreover, we show the unconditional uniqueness of mild solutions to the drift-diffusion equation in amalgam spaces

Convergence rate of Tsallis entropic regularized optimal transport

In this paper, we consider Tsallis entropic regularized optimal transport and discuss the convergence rate as the regularization parameter $\varepsilon$ goes to $0$. In particular, we establish the convergence rate of the Tsallis entropic regularized optimal transport using the quantization and shadow arguments developed by Eckstein--Nutz. We compare this to the convergence rate of the entropic regularized optimal transport with Kullback--Leibler (KL) divergence and show that KL is the fastest convergence rate in terms of Tsallis relative entropy.Comment: 21 page

Maximal regularity of the heat evolution equation on spatial local spaces and application to a singular limit problem of the Keller–Segel system

We consider the singular limit problem for the Cauchy problem of the (Patlak–) Keller–Segel system of parabolic-parabolic type. The problem is considered in the uniformly local Lebesgue spaces and the singular limit problem as the relaxation parameter $$tau$$ goes to infinity, the solution to the Keller–Segel equation converges to a solution to the drift-diffusion system in the strong uniformly local topology. For the proof, we follow the former result due to Kurokiba–Ogawa [20–22] and we establish maximal regularity for the heat equation over the uniformly local Lebesgue and Morrey spaces which are non-UMD Banach spaces and apply it for the strong convergence of the singular limit problem in the scaling critical local spaces

函数解析的方法による移流拡散方程式の特異極限問題と解の漸近挙動について

要約のみTohoku University小川卓克課

Finite time blow up and concentration phenomena for a solution to drift-diffusion equations in higher dimensions

We show the finite time blow up of a solution to the Cauchy problem of a drift-diffusion equation of a parabolic-elliptic type in higher space dimensions. If the initial data satisfies a certain condition involving the entropy functional, then the corresponding solution to the equation does not exist globally in time and blows up in a finite time for the scaling critical space. Besides there exists a concentration point such that the solution exhibits the concentration in the critical norm. This type of blow up was observed in the scaling critical two dimensions. The proof is based on the profile decomposition and the Shannon inequality in the weighted space

Figure 1 from: Osawa T, Baba Y, Suguro T, Naya N, Yamauchi T (2017) Specimen records of spiders (Arachnida: Araneae) by monthly census for 3 years in forest areas of Yakushima Island, Japan. Biodiversity Data Journal 5: e14789. https://doi.org/10.3897/BDJ.5.e14789

Figure 1 - Study area and monitoring sites