3¿ù21ÀÏ(¼ö) 17:00~17:50 5E102 ¿¬»ç: ±èº´ÇÑ(¿¬¼¼´ë) Á¦¸ñ: Amalgamation functors and homology groups in model theory. ÃÊ·Ï: (Joint work with John Goodrick, Alexei Kolesnikov/ Jung-Uk Lee, Sun Young Kim) We develop homology theory for amenable categories, covering even discrete geometric context. Best examples of amenable categories come from stable structures (the class of which is a major subject in model theory, a branch of mathematical logic). In a stable structure, we prove that the 2ndhomology group is a certain automorphism group, and any profinite abelian group can occur as it. We also classify 2-chains, and show that planar 2-chains (geometric notion) are equivalent to Lascar 2-chains (model theoretic notion).