15 citations · 48 across the 18 of their papers we have counts for
18 papers
Structure and unique factorization in concordance groups of links
Kouki Sato, Akira Yasuhara
Donald and Owens introduced two link concordance groups with a marked component and showed that they contain the knot concordance group as a direct summand with infinitely generate…
Cobordism maps in Khovanov homology and singular instanton homology II
Hayato Imori, Taketo Sano, Kouki Sato +1
This paper is a continuation of our previous work, where we defined an embedded cobordism map on the instanton cube complex that recovers the cobordism maps both in Khovanov homolo…
Cobordism maps in Khovanov homology and singular instanton homology I
Hayato Imori, Taketo Sano, Kouki Sato +1
Khovanov homology and singular instanton Floer homology are both functorial with respect to link cobordisms. Although the two homology groups are related by a spectral sequence, di…
On the slice-torus invariant from -equivariant Seiberg--Witten Floer cohomology
Nobuo Iida, Taketo Sano, Kouki Sato +1
We show that Iida--Taniguchi's -valued slice-torus invariant cannot be realized as a linear combination of Rasmussen's -invariant, Ozsváth--Szabó's -invaria…
A family of slice-torus invariants from the divisibility of Lee classes
Taketo Sano, Kouki Sato
We give a family of slice-torus invariants , each defined from the -divisibility of the reduced Lee class in a variant of reduced Khovanov homology, parameterized…
Instantons, special cycles, and knot concordance
Aliakbar Daemi, Hayato Imori, Kouki Sato +2
We introduce a framework for defining concordance invariants of knots using equivariant singular instanton Floer theory with Chern-Simons filtration. It is demonstrated that many o…
The bridge number of surface links and kei colorings
Kouki Sato, Kokoro Tanaka
Meier and Zupan introduced bridge trisections of surface links in as a 4-dimensional analogue to bridge decompositions of classical links, which gives a numerical invariant o…
An algorithm for computing the -invariant and the -invariants of Dehn surgeries
Taketo Sano, Kouki Sato
By using grid homology theory, we give an explicit algorithm for computing Ozsváth-Stipsicz-Szabó's -invariant and the -invariant of Dehn surgeries along knots in . As i…
The -equivalence classes of genus one knots
Kouki Sato
The -equivalence is an equivalence relation on the knot concordance group. This relation can be seen as a certain stable equivalence on knot Floer complexes , an…
Filtered instanton Floer homology and the homology cobordism group
Yuta Nozaki, Kouki Sato, Masaki Taniguchi
For any and oriented homology 3-sphere , we introduce a homology cobordism invariant . The values are included in the cr…
Rational homology 3-spheres and simply connected definite bounding
Kouki Sato, Masaki Taniguchi
For each rational homology 3-sphere which bounds simply connected definite 4-manifolds of both signs, we construct an infinite family of irreducible rational homology 3-spheres…
On eigenvalues of double branched covers
Kouki Sato
For a given knot, we study the minimal number of positive eigenvalues of the double branched cover over spanning surfaces for the knot. The value gives a lower bound for various ge…
A full-twist inequality for the -invariant
Kouki Sato
Hom and Wu introduced a knot concordance invariant called , which dominates many concordance invariants derived from Heegaard Floer homology. In this paper, we give a full-twi…
Topologically slice knots that are not smoothly slice in any definite 4-manifold
Kouki Sato
We prove that there exist infinitely many topologically slice knots which cannot bound a smooth null-homologous disk in any definite 4-manifold. Furthermore, we show that we can ta…
Knots that are not slice either in positons or in negatons
Kouki Sato
An oriented compact 4-manifold with boundary is called a positon (resp. negaton) if its intersection form is positive definite (resp. negative definite) and it is simply…
Heegaard Floer correction terms of -surgeries along -cablings
Kouki Sato
The Heegaard Floer correction term (-invariant) is an invariant of rational homology 3-spheres equipped with a Spin structure. In particular, the correction term of 1-surger…
Non-orientable genus of knots in punctured Spin 4-manifolds
Kouki Sato
For a closed 4-manifold and a knot in the boundary of punctured , we define to be the smallest first Betti number of non-orientable and null-homologous surfac…
Non-orientable genus of a knot in punctured
Kouki Sato, Motoo Tange
For any knot which bounds non-orientable and null-homologous surfaces in punctured , we construct a lower bound of the first Betti number of which consi…