In this paper, we develop a lower bound for the double slice genus of knot in 3-sphere using Casson-Gordon invariants. As an application, show that difference between and can be arbitrarily large. analogue to genus, also define superslice knot, give both upper bound. particular, through study degree Alexander polynomial is topological ribbon knot.

We characterize the Murasugi polynomial of an equivariant slice knot by proving a conjecture of J. Davis and S. Naik. A knot K in S is called periodic of period p if there is an orientation preserving action of Z/p on S which preserves K setwise and its fixed point set A is a circle disjoint to K. A is called the axis. Two periodic knots K0 and K1 of period p are called equivariantly concordant...

root-knot nematodes are one of the limiting factors in seedling production and new olive gardens establishment in iran. in view of find resistance cultivars to root-knot nematodes, importance of careful identification of species and races are clarified. in order to investigate root-knot nematodes on olive, soil and root samples of gardens and nursery in gorgan area were collected. in this study...

We show that all two-bridge knot and link complements are virtually fibered. We also show that spherical Montesinos knot and link complements are virtually fibered. This is accomplished by showing that such knot complements are finitely covered by great circle link complements.

Necessary and sufficient conditions are given for a satellite knot to be fibered. Any knot k̃ embeds in an unknotted solid torus Ṽ with arbitrary winding number in such a way that no satellite knot with pattern (Ṽ , k̃) is fibered. In particular, there exist nonfibered satellite knots with fibered pattern and companion knots and nonzero winding number.

We use Dowlin's spectral sequence from Khovanov homology to knot Floer prove that reduced with rational coefficients detects the figure-eight knot.

An obstructed inguinal hernia is a common surgical emergency, which presents with a variety of contents like the small intestine, omentum, and colon. Intestinal knotting is a rare entity encountered in surgical practice; it occurs when one coil of intestine wraps around the other and eventually leads to complications such as intestinal obstruction, ischemia, and gangrene. Both conditions are co...

We study the integral expression of a knot invariant obtained as the second coeecient in the perturbative expansion of Witten's Chern-Simons path integral associated with a knot. One of the integrals involved turns out to be a generalization of the classical Crofton integral on convex plane curves and it is related with invariants of generic plane curves recently deened by Arnold, with deep mot...