4 papers
Quantum enhancement polynomials associated with the canonical two-element tricbracket
Yuya Koda, Yuya Nishimura, Yuka Sakamoto
Quantum enhancement polynomials are invariants for oriented links, defined in association with an algebraic structure called a tribracket. In this paper, we focus on the particular…
The computational complexity of the solid torus core recognition problem
Yuya Nishimura
The solid torus core recognition problem is the problem that, given a knot in the solid tours, decides whether the knot is the core of the solid torus. That problem is in NP since…
The Computational Complexity of Classical Knot Recognition
Kazuhiro Ichihara, Yuya Nishimura, Seiichi Tani
The classical knot recognition problem is the problem of determining whether the virtual knot represented by a given diagram is classical. We prove that this problem is in NP, and…
Span equivalence between algebras for n-globular operads
Yuya Nishimura
We define a new equivalence between algebras for n-globular operads which is suggested in [Cottrell 2015], and show that it is a generalization of ordinary equivalence between cate…