arXiv research

New knots found with Seifert genus not matching minimal genus Seifert surfaces.

Knots' Morse-Novikov number behaves additively under connected sum and unchanged by cabling.

We prove that the Morse-Novikov number of a link L in a 3-sphere is less than or equal to twice the tunnel number of L.

Study Morse-Novikov numbers for frame spun knots and surface-links.

The paper bounds the handle number of sutured manifolds using Morse-Novikov numbers and tunnel numbers.

The Morse-Novikov number MN(L) of an oriented link L in the 3-sphere is the minimum number of critical points of a Morse map from the complement of L in the 3-sphere to the circle representing the class of a Seifert surface for L (e.g., the Morse-Novikov number of L is zero if and only if L is fibered). We develop vari…

Let $K\subset S^4$ be a 2-knot, that is, a smoothly embedded 2-sphere in $S^4$. The Morse-Novikov number $\mathcal M\mathcal N(K)$ is the minimal possible number of critical points of a Morse map $S^4\setminus K\to S^1$ belonging to the canonical class in $H^1(S^4\setminus K)$. We prove that for a classical knot $K\sub…

The abstract discusses cohomology of complex manifolds and blow-ups.

A knot is an a-small knot if its exterior does not contain closed incompressible surfaces disjoint from some incompressible Seifert surface for the knot. Using circular thin position for knots we prove that the handle number is additive under the connected sum of two a-small knots. As a consequence the Morse-Novikov nu…

The paper studies cohomology of complex manifolds using Morse-Novikov and Dolbeault-Morse-Novikov theories.

The paper proves a version of the Arnol'd conjecture for Lagrangian submanifolds in conformal symplectic geometry.

Holomorphic Euler number vanishes for certain Kähler manifolds.

Study Morse-Novikov cohomology on foliated manifolds and prove Hodge theorem.

New proof of blow-up formula for Morse-Novikov cohomology.

Researchers compute cohomology of complex non-Kähler OT manifolds.

The Morse-Novikov number MN(L) of a smooth link L in the three-dimensional sphere is by definition the minimal possible number of critical points of a regular circle-valued Morse function on the link complement (the term regular means that the Morse function must have nice behaviour in a tubular neighbourhood of L). No…

Study Morse-Novikov cohomology for 1-forms on rank 1 manifolds.

The paper shows Morse-Novikov cohomology vanishes for certain curved manifolds.

Extends Morse-Novikov Homology to include differential graded coefficients and fibration structures.

Authors compute Morse-Novikov cohomology for Inoue surfaces and prove nonexistence of certain metrics.

Vanishing theorem for $L^2$-harmonic forms on Riemannian manifolds with parallel 1-form.

A locally conformally Kahler (LCK) manifold is a complex manifold admitting a Kahler covering, with the monodromy acting on this covering by homotheties. We define three cohomology invariants, the Lee class, the Morse-Novikov class, and the Bott-Chern class, of an LCK-structure. These invariants together play the same …

New method constructs Morse-Novikov complex with infinite series coefficients.

We create a polynomial with knot-like nodal lines.

The article studies cohomology on complex manifolds and proves vanishing theorems.

In this paper we find sufficient conditions for the vanishing of the Morse-Novikov cohomology on Riemannian foliations. We work out a Bochner technique for twisted cohomological complexes, obtaining corresponding vanishing results. Also, we generalize for our setting vanishing results from the case of closed Riemannian…

Study of fibred faces of Thurston polyhedra for 2-component 2-bridge links

We use noncommutative localization to construct a chain complex which counts the critical points of a circle-valued Morse function on a manifold, generalizing the Novikov complex. As a consequence we obtain new topological lower bounds on the minimum number of critical points of a circle-valued Morse function within a …

The works of Donaldson and Mark make the structure of the Seiberg-Witten invariant of 3-manifolds clear. It corresponds to certain torsion type invariants counting flow lines and closed orbits of a gradient flow of a circle-valued Morse map on a 3-manifold. We study these invariants using the Morse-Novikov theory and H…

Study LCS structures on Lie algebras of type I, proving trivial Morse-Novikov cohomology and constructing solvmanifolds.

New dynamics in gradient fields lead to unexpected homoclinic orbits.

Study of knotted defects in smectic liquid crystals using topological knot theory.

Study rigid Lie affine foliations on compact manifolds.

A locally conformally Kahler (LCK) manifold is a complex manifold with a Kahler structure on its covering and the deck transform group acting on it by holomorphic homotheties. One could think of an LCK manifold as of a complex manifold with a Kahler form taking values in a local system $L$, called the conformal weight …

Murasugi sums can be defined as readily for Morse maps to the circle of (arbitrary) link complements in the 3-sphere as for fibrations over the circle of (fibered) link complements in the 3-sphere. As one application, I show that if a knot K has free genus m, then there is a Morse map from its complement to the circle …

In this paper we construct a Universal chain complex, counting zeros of closed 1-forms on a manifold. The Universal complex is a refinement of the well known Novikov complex; it relates the homotopy type of the manifold, after a suitable noncommutative localization, with the numbers of zeros of different indices which …

We study the cohomology $H^*_{λω}(G/Γ, {\mathbb C})$ of the deRham complex $Λ^*(G/Γ)\otimes{\mathbb C}$ of a compact solvmanifold $G/Γ$ with a deformed differential $d_{λω}=d + λω$, where $ω$ is a closed 1-form. This cohomology naturally arises in the Morse-Novikov theory. We show that for a solvable Lie group $G$ with…

Given a circle-valued Morse function of a closed oriented manifold, we prove that Reidemeister torsion over a non-commutative formal Laurent polynomial ring equals the product of a certain non-commutative Lefschetz-type zeta function and the algebraic torsion of the Novikov complex over the ring. This paper gives a gen…

We consider systems $(M,ω,g)$ with $M$ a closed smooth manifold, $ω$ a real valued closed one form and $g$ a Riemannian metric, so that $(ω,g)$ is a Morse-Smale pair, Definition~2. We introduce a numerical invariant $ρ(ω,g)\in[0,\infty]$ and improve Morse-Novikov theory by showing that the Novikov complex comes from a …

This paper extends Lusternik-Schnirelmann category to non-compact manifolds.

Study cohomologies on manifolds with locally conformally symplectic structures.

We present a new approach to Morse and Novikov theories, based on the deRham Federer theory of currents, using the finite volume flow technique of Harvey and Lawson. In the Morse case, we construct a noncompact analogue of the Morse complex, relating a Morse function to the cohomology with compact forward supports of t…

Let f be a Morse map from a closed manifold to a circle. S.P.Novikov constructed an analog of the Morse complex for f. The Novikov complex is a chain complex defined over the ring of Laurent power series with integral coefficients and finite negative part. This complex depends on the choice of a gradient-like vector fi…

Study on knot diagrams showing bridge number can differ from crossing number.

Straight numbers generalize Meander and OGC numbers for all knots.

Spatial embeddings of planar graphs can have higher unknotting numbers than crossing numbers.

The unknotting number of a knot is the minimum number of crossings one must change to turn that knot into the unknot. The algebraic unknotting number is the minimum number of crossing changes needed to transform a knot into an Alexander polynomial-one knot. We work with a generalization of unknotting number due to Math…

New measure shows how links can be untangled as twists increase.