欧拉-玻尔兹曼方程整体光滑解  

Global Existence of Smooth Solutions to the Euler-Boltzmann Equations

作　　者：浦赟 张永前 PU Yun;ZHANG Yongqian(School of Mathematical Sciences,Fudan University,Shanghai 200433,China)

机构地区：[1]复旦大学数学科学学院,上海200433

出　　处：《数学年刊（A辑）》2022年第2期119-136,共18页Chinese Annals of Mathematics

摘　　要：本文证明了Rd中具有某一类小初值的等熵欧拉-玻尔兹曼方程整体光滑解的存在性.本文首先构造了等熵欧拉-玻尔兹曼方程的局部解,并证明了局部解的适定性.此外,文中还构造了关于原方程的随时间t增加、具有良好的衰减性质的整体光滑背景解.同时,当方程的辐射项系数满足一定条件时,本文建立了关于源项的估计.通过将背景解的衰减与源项的估计结合起来,文中证明了存在整数s>d/2+1,使得背景解与原方程解的H^(s)(R^(d))×L^(2)(R+×S^(d-1);H^(s)(R^(d))范数之差始终是有界的,从而保证了原方程整体光滑解的存在性.The authors are concerned with the global existence of smooth solutions to the isentropic Euler-Boltzmann equations in Rd,with a class of small initial data.Firstly,they construct local solutions to the problem and then the wellposedness of the local solutions is proved.Also,they construct global smooth background solutions to the approximate system,which possess a nice decay as t increases.Meanwhile,estimates of the source terms are established with some assumptions on the coefficients of the radiation part.Combining the decay of the background solutions and the estimates on the source terms,the authors show that for some integer s>d/2+1,the difference of H^(s)(R^(d))×L^(2)(R+×S^(d-1);H^(s)(R^(d)))norm between approximate solutions and real solutions remains finite,which ensures the global existence of smooth solutions to original problems.

关 键 词：欧拉-玻尔兹曼方程 柯西问题 局部适定性 能量估计 整体光滑解 

分 类 号：O175.29[理学—数学]