協同学習・動機づけプロジェクト 草薙邦広のページ

Answering a question of de la Harpe and Bridson in the Kourovka Notebook, we build the explicit embeddings of the additive group of rational numbers Q in a finitely generated group

Goal of this joint work: Under certain conditions, we prove ( ∗ ) directly [i.e., without applying the theory of noncritical Belyi maps] to compute the constant “C(d, ϵ)”

Definition An embeddable tiled surface is a tiled surface which is actually achieved as the graph of singular leaves of some embedded orientable surface with closed braid

Shigeyuki MORITA Casson invariant and structure of the mapping class group.. .) homology cobordism invariants. Shigeyuki MORITA Casson invariant and structure of the mapping

This abundance of braid group actions enhances our beliefs that triangulated and derived categories are the right place to search for 4-dimensional TQFTs, and that quantum invariants

Motivated by ongoing work on related monoids associated to Coxeter systems, and building on well-known results in the semi-group community (such as the description of the simple

Our bound does not prove that every Cayley graph is a ˇ Cerný Cayley graph, but it does work for certain Cayley graphs of cyclic groups, dihedral groups, sym- metric groups,

The Grothendieck-Teichm¨ uller group and the outer automorphism groups of the profinite braid groups (joint.. work with