{ "id": "2301.08309", "version": "v1", "published": "2023-01-19T20:49:05.000Z", "updated": "2023-01-19T20:49:05.000Z", "title": "A singular Kazdan-Warner problem on a compact Riemann surface", "authors": [ "Xiaobao Zhu" ], "comment": "21 pages", "categories": [ "math.AP", "math.DG" ], "abstract": "Let $(M,g)$ be a compact Riemann surface with unit area, $h\\in C^{\\infty}(M)$ a function which is positive somewhere, $\\rho>0$, $p_i\\in M$ and $\\alpha_i\\in(-1,+\\infty)$ for $i=1,\\cdots,\\ell$, we consider the mean field equation \\begin{align*} \\Delta v + 4\\pi\\sum_{i=1}^{\\ell}\\alpha_i\\left(1-\\delta_{p_i}\\right) = \\rho\\left(1-\\frac{he^v}{\\int_Mhe^vd\\mu}\\right), \\end{align*} on $M$, where $\\Delta$ and $d\\mu$ are the Laplace-Beltrami operator and the area element of $(M,g)$ respectively. Using variational method and blowup analysis, we prove some existence results in the critical case $\\rho=8\\pi(1+\\min\\{0,\\min_{1\\leq i\\leq\\ell}\\alpha_i\\})$. These results can be seen as partial generalizations of works of Chen-Li (J. Geom. Anal. 1: 359--372, 1991), Ding-Jost-Li-Wang (Asian J. Math. 1: 230--248, 1997), Mancini (J. Geom. Anal. 26: 1202--1230, 2016), Yang-Zhu (Proc. Amer. Math. Soc. 145: 3953--3959, 2017), Sun-Zhu (arXiv:2012.12840) and Zhu (arXiv:2212.09943). Among other things, we prove that the blowup (if happens) must be at the point where the conical angle is the smallest one and $h$ is positive, this is the most important contribution of our paper.", "revisions": [ { "version": "v1", "updated": "2023-01-19T20:49:05.000Z" } ], "analyses": { "keywords": [ "compact riemann surface", "singular kazdan-warner problem", "mean field equation", "unit area", "laplace-beltrami operator" ], "note": { "typesetting": "TeX", "pages": 21, "language": "en", "license": "arXiv", "status": "editable" } } }