Fast FPT-Approximation of Branchwidth

Explore a comprehensive lecture on fast FPT-approximation of branchwidth, delivered by Tuukka Korhonen at the Hausdorff Center for Mathematics. Delve into the concept of branchwidth and its role in decomposing graphs and connectivity functions into tree-like structures. Discover a novel framework for designing fixed-parameter tractable 2-approximation algorithms for branchwidth of connectivity functions. Examine the two key ingredients of this framework: a structural theorem and efficient implementation of refinement operations. Learn about specific applications of this general framework and gain insights into graph parameters, algorithms, and formulas related to branchwidth approximation. The 32-minute talk, which includes an introduction, definitions, and detailed explanations, is based on joint work with Fedor Fomin.