The two-dimensional Keller-Segel model after blow-up
Schmeiser, Christian; Dolbeault, Jean (2009), The two-dimensional Keller-Segel model after blow-up, Discrete and Continuous Dynamical Systems. Series A, 25, 1, p. 109-121. http://dx.doi.org/10.3934/dcds.2009.25.109
TypeArticle accepté pour publication ou publié
External document linkhttp://hal.archives-ouvertes.fr/hal-00158767/en/
Journal nameDiscrete and Continuous Dynamical Systems. Series A
MetadataShow full item record
Abstract (EN)In the two-dimensional Keller-Segel model for chemotaxis of biological cells, blow-up of solutions in finite time occurs if the total mass is above a critical value. Blow-up is a concentration event, where point aggregates are created. In this work global existence of generalized solutions is proven, allowing for measure valued densities. This extends the solution concept after blow-up. The existence result is an application of a theory developed by Poupaud, where the cell distribution is characterized by an additional defect measure, which vanishes for smooth cell densities. The global solutions are constructed as limits of solutions of a regularized problem. A strong formulation is derived under the assumption that the generalized solution consists of a smooth part and a number of smoothly varying point aggregates. Comparison with earlier formal asymptotic results shows that the choice of a solution concept after blow-up is not unique and depends on the type of regularization. This work is also concerned with local density profiles close to point aggregates. An equation for these profiles is derived by passing to the limit in a rescaled version of the regularized model. Solvability of the profile equation can also be obtained by minimizing a free energy functional.
Subjects / KeywordsKeller-Segel; chemotaxis; blow-up; aggregation; measure valued solutions; defect measure
Showing items related by title and author.
Fernandez, Javier; Escobedo, Miguel; Dolbeault, Jean; Blanchet, Adrien (2010) Article accepté pour publication ou publié
Two-dimensional Keller-Segel model: Optimal critical mass and qualitative properties of the solutions Blanchet, Adrien; Dolbeault, Jean; Perthame, Benoît (2006) Article accepté pour publication ou publié