Sayaka Yamada

collaborators

2 papers

math.GT2013

Unknotting rectangular diagrams of the trivial knot by exchanging moves

Chuichiro Hayashi, Sayaka Yamada

If a rectangular diagram represents the trivial knot, then it can be deformed into the rectangular diagram with only two vertical edges by a finite sequence of merge operations and…

math.GT2010

Minimal unknotting sequences of Reidemeister moves containing unmatched RII moves

Chuichiro Hayashi, Miwa Hayashi, Minori Sawada +1

Arnold introduced invariants $J^{+}$ , $J^{-}$ and $S t$ for generic planar curves. It is known that both $J^{+} /2 + S t$ and $J^{-} /2 + S t$ are invariants for generic spherical curves. App…