116 research outputs found

    The ν+\nu^+-equivalence classes of genus one knots

    Full text link
    The ν+\nu^+-equivalence is an equivalence relation on the knot concordance group. This relation can be seen as a certain stable equivalence on knot Floer complexes CFKCFK^{\infty}, and many concordance invariants derived from Heegaard Floer theory are invariant under the equivalence. In this paper, we show that any genus one knot is ν+\nu^+-equivalent to one of the trefoil, its mirror and the unknot.Comment: 46 pages, 8 figures;(v2)typos correcte

    A family of slice-torus invariants from the divisibility of reduced Lee classes

    Full text link
    We give a family of slice-torus invariants, one defined for each prime element cc in a principal ideal domain RR, from the cc-divisibility of the reduced Lee class in a variant of reduced Khovanov homology. It is proved that this family contains the Rasmussen invariant sFs^F over any field FF. Moreover, computational results show that the invariants corresponding to (R,c)=(Z,2)(R, c) = (\mathbb{Z}, 2), (Z,3)(\mathbb{Z}, 3) and (Z[i],1+i)(\mathbb{Z}[i], 1 + i) are distinct from sQs^\mathbb{Q}.Comment: 38 page

    Non-orientable genus of a knot in punctured CP2\mathbb{C}P ^2

    Full text link
    For any knot KK which bounds non-orientable and null-homologous surfaces FF in punctured nCP2n\mathbb{C}P^2, we construct a lower bound of the first Betti number of FF which consists of the signature of KK and the Heegaard Floer dd-invariant of the integer homology sphere obtained by 11-surgery along KK. By using this lower bound, we prove that for any integer kk, a certain knot cannot bound any surface which satisfies the above conditions and whose first Betti number is less than kk.Comment: 11 pages, 6 figure
    corecore