New algorithm calculates Steenrod squares in Khovanov cohomology.
problem Computing Steenrod squares in Khovanov cohomology.
method Flow category simplification techniques to calculate second Steenrod square and Bockstein homomorphisms.
result Observation of new homotopy types and evidence against CP2 summands. We extend the definition of Bockstein basis σ(G) to nilpotent groups G. A metrizable space X is called a {\it Bockstein space} if dimG(X)=sup{dimH(X)∣H∈σ(G)} for all Abelian groups G. Bockstein First Theorem says that all compact spaces are Bockstein spaces. Here are the main results of the pape…
We consider a simple and natural coboundary operator, on the Lie algebra valued differential forms on a manifold, which in the abelian case reduces to usual exterior derivative of such forms. Using the corresponding de Rham cohomology Lie superalgebra H*(M,G) we obtain numerical smooth invariants--as opposed to homotop…
We prove torsion constraints in Khovanov homology for certain links.
problem Understanding torsion in Khovanov homology for specific knot types.
method Establishing an algebraic relation between Bockstein and Turner differentials on Khovanov homology over Z2. result Prove no 2k-torsion for k>1 in Khovanov homology of Z2-thin links. We prove a generalization of the Edwards-Walsh Resolution Theorem: Theorem: Let G be an abelian group for which PG equals the set of all primes P, where PG={p∈P:Z(p)∈ Bockstein Basis σ(G)}. Let n in N and let K be a connected CW-complex with πn(K)≅G, πk(K)≅0 for…
Spectral sequence connects knot homologies via algebraic geometry.
problem Connecting algebraic and geometric knot homologies.
method Bigraded spectral sequence from gl(0)-homology to knot Floer homology.
result Constructs a Bockstein-type spectral sequence.
For a fixed closed manifold P, we construct a cobordism category of embedded manifolds with a single Baas-Sullivan singularity of type P. Our main theorem identifies the homotopy type of the classifying space of this cobordism category with that of the infinite loop-space of a certain spectrum related to the spectr…
In the paper titled "Bockstein basis and resolution theorems in extension theory" (arXiv:0907.0491v2), we stated a theorem that we claimed to be a generalization of the Edwards-Walsh resolution theorem. The goal of this note is to show that the main theorem from (arXiv:0907.0491v2) is in fact equivalent to the Edwards-…
We answer a weaker version of the classification problem for the homotopy types of (n−2)-connected closed orientable (2n−1)-manifolds. Let n≥6 be an even integer, and X be a (n−2)-connected finite orientable Poincaré (2n−1)-complex such that Hn−1(X;Q)=0 and Hn−1(X;Z2)=0. The…
Characterizes a general range decreasing group homomorphism.
problem Understanding range decreasing group homomorphisms in the entire mapping group.
method Characterization of a general range decreasing group homomorphism.
result Computes a particular class of homomorphisms and identifies all range decreasing group homomorphisms on specific mapping groups.
We construct an algebra of non-trivial homological operations on Khovanov homology with coefficients in Z2 generated by two Bockstein operations. We use the unified Khovanov homology theory developed by the first author to lift this algebra to integral Khovanov homology. We conjecture that these two algebras…
We extend certain homomorphisms defined on the higher Torelli subgroups of the mapping class group to crossed homomorphisms defined on the entire mapping class group. In particular, for every k≥2, we construct a crossed homomorphism εk which extends Morita's homomorphism τ~k to the entire mapping clas…
Two crossing homomorphisms on braid groups are shown to be equivalent.
problem Comparing two definitions of crossing homomorphisms on braid groups.
method Diagrammatic and algebraic definitions of crossing homomorphisms compared and computed for simple braids.
result Diagrammatic and algebraic crossing homomorphisms are equivalent.
The study classifies homomorphisms from mapping class groups using finite subgroups.
problem Classifying homomorphisms from mapping class groups.
method Using finite subgroups to classify homomorphisms.
result Only finitely many mapping class groups have non-trivial homomorphisms into Homeo(S^n) for any n.
Study of Chebyshev-Frobenius homomorphism in 3-manifold skein modules.
problem Exploring the Chebyshev-Frobenius homomorphism in 3-manifold skein modules.
method Generalization of splitting homomorphism for stated skein modules of 3-manifolds.
result Existence and properties of Chebyshev-Frobenius homomorphism for 3-manifold skein modules.
Study on singularities of bundle homomorphisms induced by Morin maps.
problem Characterizing singular points of bundle homomorphisms.
method Analyzing conditions for singularities induced by Morin maps, using Hamilton vector fields for contact structures.
result Characterization of singularities in bundle homomorphisms induced by Morin maps.
Graph homomorphism numbers embed graphs for classification.
problem Graph classification using graph homomorphisms.
method Embed graphs into vectors using homomorphism numbers.
result Homomorphism vectors are universal for approximating graph invariants.
New conditions for weighted composition operators in group homomorphisms.
problem Conditions for weighted composition operators in group homomorphisms.
method Range decreasing group homomorphisms.
result New insights into weighted composition operators and their algebraic structure.
Study homomorphisms from groups to 3-manifold fundamental groups.
problem Understanding homomorphisms between groups and 3-manifold fundamental groups.
method Proves foundational results and answers specific questions.
result Answers questions posed by Reid-Wang-Zhou and Agol-Liu.
New homomorphisms from knot Floer homology help classify knots.
problem Classifying knots based on their concordance properties.
method Defined an infinite family of concordance homomorphisms using knot Floer complexes.
result Explicitly computable homomorphisms that are linearly independent.
New homomorphism from Khovanov homology for knot concordance.
problem Understanding smooth concordance of knots.
method Modulo equivalence relation on Khovanov chain complex.
result Strictly stronger than Rasmussen invariants.
Stability of Lie group homomorphisms and subgroups via Moser type argument.
problem When a deformation of Lie group homomorphisms and subgroups is trivial.
method Moser type argument for compact groups.
result Stability results for compact Lie groups.
Classifies homomorphisms from braid groups, proving their extensions to automorphisms.
problem Classifying homomorphisms from commutator subgroups of braid groups.
method Theory of totally symmetric sets.
result Each nontrivial homomorphism extends to an automorphism of the braid group.
Classifies homomorphisms between specific braid groups.
problem Classifying homomorphisms between braid groups.
method Complete classification through recursive approach.
result Recursive classification of homomorphisms between braid groups.
We introduce the notion of tight homomorphism into a locally compact group with nonvanishing bounded cohomology and study these homomorphisms in detail when the target is a Lie group of Hermitian type. Tight homomorphisms between Lie groups of Hermitian type give rise to tight totally geodesic maps of Hermitian symmetr…
Paper surveys Johnson homomorphisms and related tools.
problem Understanding generalized Johnson homomorphisms and their stable images.
method Surveying and unifying various related threads in literature using Hodge theory.
result Clarification of existing results and relationships among Johnson homomorphisms.
A chord index homomorphism for knots in thickened surfaces is constructed.
problem Knot invariants in thickened surfaces.
method Constructing a chord index homomorphism from a subgroup of H1(Σ,Z) to chord indices of a knot K in ΣimesI. result Derived knot invariants from the homomorphism.
Study classifies biharmonic and harmonic homomorphisms between specific Lie groups.
problem Classifying biharmonic and harmonic homomorphisms between Riemannian three-dimensional unimodular Lie groups.
method Classification based on left invariant Riemannian metrics.
result Classification of biharmonic and harmonic homomorphisms between specific Lie groups.
Study on Euler class and flux homomorphisms for non-orientable surfaces.
problem Investigate Euler class and flux homomorphisms for non-orientable surfaces.
method Analyze Euler class and flux homomorphisms for non-orientable compact surfaces with one boundary component.
result Prove the simplicity of the kernel of the flux homomorphisms, implying the non-existence of invariants analogous to the Calabi invariant.
We examine functorial and homotopy properties of the exotic characteristic homomorphism in the category of Lie algebroids which was lastly obtained by the authors in [4]. This homomorphism depends on a triple (A,B,∇) where B ⊂ A are regular Lie algebroids, both over the same regular foliated manifold (M,…
We extend each higher Johnson homomorphism to a crossed homomorphism from the automorphism group of a finite-rank free group to a finite-rank abelian group. We also extend each Morita homomorphism to a crossed homomorphism from the mapping class group of once-bounded surface to a finite-rank abelian group. This improve…
A new homomorphism connects group actions on circles to Euler classes.
problem Understanding group actions on circles and their implications.
method Using crossed homomorphisms and Poincaré translation numbers.
result Relates the Euler class of actions to a specific homomorphism.
The paper disproves a conjecture about satellite maps not inducing homomorphisms.
problem Satellite maps and their impact on knot concordance groups.
method Casson-Gordon signatures and n-solvable filtration analysis. result Examples of satellite maps that act like homomorphisms but do not induce them.
The paper extends Johnson homomorphisms to groups with extended N-series.
problem Johnson homomorphisms for mapping class groups.
method Developed a theory of Johnson homomorphisms for groups with extended N-series.
result Many known and new variants of Johnson homomorphisms.
We propose an approach to study non-Abelian Iwasawa theory, using the idea of Johnson homomorphisms in low dimensional topology. We introduce arithmetic analogues of Johnson homomorphisms/maps, called the p-Johnson homomorphisms/maps, associated to the Zassenhaus filtration of a pro-p Galois group over a Z_p-extension …
Satellite operations with winding number ≠ 1 are not homomorphisms.
problem Characterizing homomorphisms in satellite operations.
method Using d-invariants of branched covers and Torelli group properties. result Satellite operations with winding number ≠ 1 are not homomorphisms.
Study of handlebody group intersections with Torelli and Johnson kernels.
problem Intersection of handlebody group with Torelli and Johnson kernels.
method Use Birman--Craggs--Johnson (BCJ) homomorphism to study intersections and compute cup products.
result Determine images of BCJ homomorphism restricted to handlebody group intersections and compute cup products.
Homomorphism from braid groups to Steinberg groups defined.
problem Understanding the relationship between braid groups and Steinberg groups.
method Construction of a homomorphism from braid groups to Steinberg groups.
result Description of the image and kernel of the homomorphism.
Johnson and Livingston have characterized peripheral structures in homomorphs of knot groups. We extend their approach to the case of links. The main result is an algebraic characterization of all possible peripheral structures in certain homomorphic images of link groups.
The paper studies symmetries in quandles and their relative versions.
problem Understanding symmetries in quandle structures and their transformations.
method Introducing relative versions of inner automorphism and transvection groups, and using them to characterize and classify surjective homomorphisms.
result Characterization of connected homomorphisms and classification of quandle structures under certain symmetry assumptions.
The paper studies new filtrations and homomorphisms related to mapping class groups and 3-manifold invariants.
problem Exploring new filtrations and homomorphisms in mapping class groups.
method Investigates a new filtration introduced by Habiro and Massuyeau, compares it with existing filtrations, and connects it to the LMO functor.
result Alternative Johnson homomorphisms can be read in the tree reduction of the LMO functor.
If phi: G-->G' is a surjective homomorphism, we prove that the twisted Alexander polynomial of G is divisible by the twisted Alexander polynomial of G'. As an application, we show non-existence of surjective homomorphism between certain knot groups.
Study proves equality of LS-category and cohomological dimension for specific group homomorphisms.
problem Proving equality of LS-category and cohomological dimension for specific group homomorphisms.
method Analyzing epimorphisms and homomorphisms between specific types of almost nilpotent and virtually nilpotent groups.
result Equality of LS-category and cohomological dimension for specified group homomorphisms.
The paper shows how surjective homomorphisms between surface braid groups factor and computes their automorphism groups.
problem Characterizing surjective homomorphisms and automorphisms of surface braid groups.
method Analyzing the structure of surface braid groups and their homomorphisms.
result Surjective homomorphisms factor through forgetful maps and automorphisms are geometric.
Study de Rham homomorphism for Lipschitz cohomologies on metric simplicial complexes.
problem Triviality of de Rham homomorphism kernel and non-increasing monotonicity of parameters.
method Regularization in Lipschitz de Rham calculus on metric simplicial complexes with bounded geometry.
result Explicit specification of non-trivial cohomology classes for a sequence of parameters.
New homomorphism from Khovanov homology gives slice genus bounds.
problem Understanding slice genus of knots.
method A 1-parameter family of concordance homomorphisms from Khovanov homology.
result Can prove linear independence of certain knot families.
Let K be the kernel of an epimorphism G -> Z, where G is a finitely presented group. If K has infinitely many subgroups of index 2, 3, or 4, then it has uncountably many. Moreover, if K is the commutator subgroup of a classical knot group G, then any homomorphism from K onto the symmetric group S_2 lifts to a homomorph…
Johnson has defined a surjective homomorphism from the Torelli subgroup of the mapping class group of the surface of genus g with one boundary component to ∧3H, the third exterior product of the homology of the surface. Morita then extended Johnson's homomorphism to a homomorphism from the entire mapping cla…