Study exotic Dehn twists in 4-manifolds, producing first known exotic diffeomorphisms.
problem Detecting exotic diffeomorphisms in 4-manifolds.
method 2-parameter families Seiberg-Witten theory over RP2. result Constructed the smallest closed 4-manifold with exotic diffeomorphisms.
Exotic diffeomorphisms found on complex surfaces and 4-manifolds.
problem Finding exotic diffeomorphisms on 4-manifolds.
method Minimal complex surfaces and spin 4-manifolds with S3 boundary. result First known instances of exotic diffeomorphisms of irreducible 4-manifolds.
The paper proves properties of branched covers of specific knots and tori.
problem Investigating the smoothness and diffeomorphism of specific 4-manifolds.
method Analyzing double branched covers of twist-roll spun knots and turned twisted tori, applying techniques to show diffeomorphism.
result Proves that certain 4-manifolds are diffeomorphic to standard manifolds.
Classifies periodic diffeomorphisms and hyperelliptic involutions on surfaces.
problem Classifying periodic diffeomorphisms and involutions on surfaces.
method Refinement of Ishizaka's result using Dehn twist presentations.
result Dehn twist presentations of hyperelliptic periodic mapping classes.
Gluck twisting certain knots results in standard 4-spheres.
problem Understanding when Gluck twists yield standard 4-spheres.
method Analyzing smooth homotopy 4-spheres and diffeomorphisms.
result Infinite collection of twisted doubles of corks are standard.
The Price twist creates three 4-manifolds from a 4-sphere.
problem Understanding the properties of a non-simply connected 4-manifold created from a 4-sphere.
method Cutting and pasting operation on a P2-knot S in a 4-manifold. result The non-simply connected 4-manifold τS(S4) is studied for Kinoshita type P2-knots. The Gluck twist preserves the diffeomorphism type of certain satellite 2-knots.
problem Preserving the diffeomorphism type of satellite 2-knots under the Gluck twist.
method Using new descriptions of satellite 2-knots, the paper shows that the Gluck twist does not change the diffeomorphism type of certain satellite 2-knots in three ways.
result The Gluck twist preserves the diffeomorphism type of certain satellite 2-knots.
New findings about twists in 4-sphere diffeomorphisms.
problem Understanding isotopy classes of diffeomorphisms in 4-sphere.
method Using Cerf theory and twists along Montesinos twins.
result The subgroup of twists along Montesinos twins is trivial or cyclic of order two.
Symplectomorphisms of a disc are decomposed using twist diffeomorphisms to study periodic points.
problem Understanding periodic points in symplectomorphisms of a 2-disc.
method Decomposition into positive twist diffeomorphisms and application of Conley index theory.
result A priori information about periodic points determines a mapping class that forces additional periodic points.
Study on four-dimensional Dehn twists and Milnor fibrations, revealing new phenomena.
problem Understanding the monodromy of Milnor fibrations of surface singularities.
method Using Seiberg-Witten invariant and monopole Floer homology.
result Infinite order non-triviality results for boundary Dehn twists.
We give a simple criterion when a Gluck twisting an odd smooth 4-manifold along a 2-sphere S⊂X does not change its diffeomorphism type. We obtain this by handlebody techniques and plug twisting operation, getting a slightly stronger version of the known fact that Gluck twisting of a 2-sphere S⊂X of a …
Study on realizing subgroup twists in 3-manifolds.
problem Realizing subgroups of twist groups in 3-manifolds.
method Analyzing Nielsen realization problem for Twist(M) subgroups, applying to Burnside problem.
result Nontrivial subgroups of Twist(M) are realized by diffeomorphisms if and only if they are cyclic and M is a connected sum of lens spaces.
Proved boundary Dehn twist is exotic for Milnor fibers with specific conditions.
problem Characterizing exotic diffeomorphisms on Milnor fibers.
method Compared family relative Bauer--Furuta invariants of mapping tori.
result Boundary Dehn twist is an exotic diffeomorphism under given conditions.
Study shows Dehn twists on certain 4-manifolds cannot be realized by finite order diffeomorphisms.
problem Realization of Dehn twists as finite order diffeomorphisms on spin 4-manifolds.
method Use Y. Kato's 10/8-type inequality for involutions and its refinement.
result Dehn twists about specific spheres in certain 4-manifolds are not homotopic to finite order diffeomorphisms.
Let K \subset Y be a knot in a three manifold which admits a longitude-framed surgery such that the surgered manifold has first Betti number greater than that of Y. We find a formula which computes the twisted Floer homology of the surgered manifold, in terms of twisted knot Floer homology. Using this, we compute the t…
New handle diagrams show infinite order corks in 4-manifolds.
problem Existence of infinite order corks in 4-manifolds.
method Translated earlier proof into handle diagrams and conditions on torus twists.
result First handle diagrams of infinite order corks.
Heegaard diagrams for 5-manifolds help in understanding their structure.
problem Understanding the structure of 5-dimensional manifolds.
method Introducing a version of Heegaard diagrams for 5-dimensional cobordisms and manifolds, showing diffeomorphisms through specific moves.
result Every smooth 5-manifold can be represented by a Heegaard diagram, and diagrams representing diffeomorphic manifolds are related by certain moves.
Classifies central extensions for area-preserving diffeomorphisms and shows they are fuzzy sphere limits.
problem Classifying central extensions for area-preserving diffeomorphisms.
method Classifying central extensions and showing they are fuzzy sphere limits of Kac-Moody cocycles.
result Central extensions are fuzzy sphere limits of Kac-Moody cocycles for large k.
Study shows non-cyclic groups of diffeomorphisms can't act on certain 3-manifolds.
problem Realization of finite groups as diffeomorphisms on specific 3-manifolds.
method Analysis of group actions on connected sums of S2imesS1. result No non-cyclic subgroup of twist subgroup can be realized by diffeomorphisms.
The paper generalizes Yang-Mills theory to study four-manifold topology.
problem Understanding the topology of diffeomorphism groups of four-manifolds.
method Path integral formulation of supersymmetric Yang-Mills coupled to conformal supergravity.
result The invariants may contain nontrivial information about the topology of the diffeomorphism group.
Generators of the 4-sphere's smooth mapping class group via diffeomorphisms of Montesinos twins.
problem Understanding the smooth mapping class group of the 4-sphere.
method Homomorphism from loops of 2-spheres to smooth mapping class group, generators as twists along Montesinos twins.
result Generators of the image of the homomorphism as diffeomorphisms of Montesinos twins.
Algorithm constructs Kirby diagrams for 4D open books.
problem Constructing Kirby diagrams for 4D open books.
method Algorithm using Heegaard diagrams of pages.
result Diffeomorphic open books constructed with different pages and monodromies.
Survey on distinguishing G_2-manifolds using metrics and constructions.
problem Distinguishing G_2-manifolds that are topologically but not diffeomorphically equivalent.
method Invariants and constructions like twisted connected sum and extra-twisted connected sum.
result Realization of G_2-manifolds with differing invariants.
New results on localization of exotic diffeomorphisms in 4-manifolds.
problem Understanding when groups of exotic diffeomorphisms can be localized to smaller embedded submanifolds.
method Analyzing families Seiberg-Witten theory, Dehn twists, and properties of Seifert fibered homology spheres.
result Exotic diffeomorphisms cannot be localized to topologically embedded rational homology balls or homology spheres.
Study of contractible manifolds and their twists to determine if they are S4.
problem Determine if a specific manifold is S4 using twists and handlebody descriptions. method Analyze two contractible manifolds, one Stein and one non-Stein, with non-trivial boundary mapping classes. Use a specific homotopy sphere to test if it is S4. result Show that a specific manifold is indeed S4. We initiate the study of the monoid of right-veering diffeomorphisms on a compact oriented surface with nonempty boundary. The monoid strictly contains the monoid of products of positive Dehn twists. We explain the relationship to tight contact structures and open book decompositions.
The study connects specific circle embeddings to 4-manifold diffeomorphisms.
problem Understanding diffeomorphisms of 4-manifolds from specific circle embeddings.
method Using a parameterised surgery map to relate framed embeddings of S^1 to mapping class groups.
result Established connections between grasper families and known diffeomorphisms.
We study diffeomorphisms of compact, oriented surfaces, developing methods of distinguishing those which have positive factorizations into Dehn twists from those which satisfy the weaker condition of right veering. We use these to construct open book decompositions of Stein-fillable 3-manifolds whose monodromies have n…
Example of non-smooth isotopy using K3 surfaces.
problem Non-smooth isotopy examples in 4-manifolds.
method Dehn twist along a 3-sphere in K3 surfaces' connected sum.
result First example of self-diffeomorphisms isotopic to identity but not smoothly.
We give a method for obtaining infinitely many framed knots which represent a diffeomorphic 4-manifold. We also study a relationship between the n-shake genus and the 4-ball genus of a knot. Furthermore we give a construction of homotopy 4-spheres from a slice knot with unknotting number one.
New non-orientable 4-manifolds created via knotting operations.
problem Creating non-orientable 4-manifolds with specific properties.
method Twisting operations on embedded spheres and projective planes.
result Existence of non-diffeomorphic manifolds homeomorphic to Y. Topological twists for 4d N=2 theories depend on spacetime type, gerbe connections, and generalized spin-c structures.
problem Defining topologically twisted partition functions for 4d N=2 theories.
method Topological twisting for general 4d N=2 theories, introducing generalized spin-c structures.
result Topological partition functions depend on spacetime type, gerbe connections, and generalized spin-c structures.
New proof using Heegaard Floer theory for non-extendable twists.
problem Non-extendable twists in 4-manifolds with group actions.
method Heegaard Floer homology approach.
result Different proof of Auckly-Kim-Melvin-Ruberman's phenomenon.
Surface corks modify 4-manifold structures without changing their homeomorphism type.
problem Understanding how to change 4-manifold structures using surface corks.
method Introducing surface corks as compact, contractible submanifolds intersecting smoothly embedded surfaces in 4-manifolds.
result Explicit construction of a transverse surface cork that is diffeomorphic to a 4-ball.
The paper creates non-isotopic but homotopic diffeomorphisms in 4-manifolds.
problem Creating non-isotopic but homotopic diffeomorphisms in 4-manifolds.
method Surgery along Θ-graphs and use of a twisted characteristic class.
result Constructs countably many non-isotopic but homotopic diffeomorphisms.
Unique symplectic fillings for certain contact manifolds up to diffeomorphism.
problem Identifying unique symplectic fillings for contact manifolds.
method Analysis of a degree-theoretic evaluation map on a moduli space of holomorphic spheres.
result Simply connected contact manifolds with subcritical Stein fillings have a unique symplectically aspherical filling up to diffeomorphism.
In this paper, we want to construct a one-to-one correspondence from the set of diffeomorphism classes of spin d-twisted homology $\mc P^3$ to the set of isotopy classes of the embedding from S3 to S6, which is a generalization of the Montgomery-Yang correspondence. Furthermore, we will apply this generalized c…
Generalized Dehn twists in surfaces and 3D relate to homology and skein algebras.
problem Understanding and classifying Dehn twists in various contexts.
method Algebraic and geometric constructions, including automorphisms of fundamental groups and diffeomorphisms.
result Generalized Dehn twists are realized as diffeomorphisms and have algebraic structures.
Homotopy 4-spheres created by iterated Gluck twists of S^4.
problem Understanding the creation and properties of homotopy 4-spheres.
method Using iterated Gluck twists and handle cancellations to show homotopy equivalence to S^4.
result Homotopy spheres Σ_n formed by doubling an infinite order loose-cork are homotopy equivalent to S^4.
Boundary Dehn twists become trivial after abelianization.
problem Understanding the behavior of boundary Dehn twists in smooth mapping classes.
method Constructing diffeomorphisms and showing commutators represent boundary Dehn twists.
result Boundary Dehn twists become trivial after abelianization.
New methods prove non-squeezing in locally conformal symplectic geometry.
problem Non-squeezing theorem in locally conformal symplectic geometry.
method Generating functions and spectral selectors for lcs Hamiltonian diffeomorphisms.
result Proves a non-squeezing theorem in S1imesR2nimesS1. New insights into exotic smoothings of R^4 via group actions and corks.
problem Understanding diffeotopy groups and exotic smoothings of R^4.
method Explicit group actions and cork theory.
result Uncountably many isotopy classes of self-diffeomorphisms for exotic smoothings of R^4.
We exhibit the first examples of closed 7-dimensional Riemannian manifolds with holonomy G_2 that are homeomorphic but not diffeomorphic. These are also the first examples of closed Ricci-flat manifolds that are homeomorphic but not diffeomorphic. The examples are generated by applying the twisted connected sum constru…
Study of codimension-1 embeddings in 3-manifolds using twist maps and push maps.
problem Embedding 3-manifolds in specific topological spaces.
method Sphere twist maps and push maps to construct codimension-1 spun embeddings.
result Every closed orientable 3-manifold admits a codimension-1 spun embedding in specific spaces.
We define cusp-decomposable manifolds and prove smooth rigidity within this class of manifolds. These manifolds generally do not admit a nonpositively curved metric but can be decomposed into pieces that are diffeomorphic to finite volume, locally symmetric, negatively curved manifolds with cusps. We prove that the gro…
Heegaard Floer homology invariant obstructs certain 3-manifold embeddings.
problem Obstructing embeddings of specific 3-manifolds.
method Heegaard Floer homology with twisted coefficients.
result Invariant obstructs embeddings of certain 3-manifolds.
We continue our study of the monoid of right-veering diffeomorphisms on a compact oriented surface with nonempty boundary, introduced in [HKM2]. We conduct a detailed study of the case when the surface is a punctured torus; in particular, we exhibit the difference between the monoid of right-veering diffeomorphisms and…
We study a deformation of infinitesimal diffeomorphisms of a smooth manifold. The deformation is based on a general twist. This leads to a differential geometry on a noncommutative algebra of functions whose product is a star-product. The class of noncommutative spaces studied is very rich. Non-anticommutative superspa…