The paper constructs exotic complex projective surfaces using rational blowdowns.
problem Finding exotic complex projective surfaces with specific invariants.
method Rational blowdowns and construction of Kollár--Shepherd-Barron--Alexeev surfaces.
result First exotic surfaces constructed, including minimal and symplectic ones.
In this paper we introduce exotic twisted T-equivariant K-theory of loop space LZ depending on the (typically non-flat) holonomy line bundle LB on LZ induced from a gerbe with connection B on Z. We also define exotic twisted T-equivariant Chern character that maps the exotic tw…
Paper finds exotic diffeomorphisms on specific 4-manifolds.
problem Understanding exotic diffeomorphisms on 4-manifolds with b2+=2. method Comparing winding numbers of parameter families.
result 2\mathbb{C}\mathbb{P}^2 \# 10 (-\mathbb{C}\mathbb{P}^2) admits exotic diffeomorphisms.
New method uses Floer homology to create exotic disk pairs.
problem Creating exotic disk pairs in 4-manifolds.
method Singular instanton Floer homology with Chern--Simons filtration.
result Constructs exotic pairs of slice disks and knots.
New exotic 4D spaces with nontrivial mappings.
problem Creating exotic copies of R4 with nontrivial mapping class groups. method Modification of diffeomorphism corks to make exteriors simply-connected.
result Construct exotic copies of R4 with mapping class groups of arbitrarily large rank. The study distinguishes exotic R^4's using knot Floer homology and Casson handles.
problem Distinguishing exotic R^4's with different knot Floer homologies.
method Using Gadgil's end Floer homology and Casson handles.
result A countably infinite family of pairwise nondiffeomorphic chiral exotic R^4's.
New exotic 4D spaces found using knot slicing techniques.
problem Finding non-diffeomorphic exotic 4D spaces.
method Using RBG links to create slice knots with non-diffeomorphic complements.
result Distinguished new exotic 4D spaces using end Floer homology.
Study exotic tori and their SL_d(Z) actions, proving many do not admit nontrivial actions.
problem Characterize exotic tori admitting SL_d(Z) actions.
method Compute mapping class groups, analyze homology actions, and prove non-existence of nontrivial actions.
result Many exotic tori do not admit nontrivial SL_d(Z) actions.
Constructs genus-3 Lefschetz fibrations and exotic 4-manifolds with specific b2+ values.
problem Creating exotic 4-manifolds with specific second Betti number.
method Explicit construction of genus-3 Lefschetz fibrations and use of Luttinger surgery and twisted fiber sum.
result Explicit construction of exotic minimal symplectic 4-manifolds with b2+=3. Kirby diagrams for exotic R^4's constructed from specific knot complements.
problem Identifying and visualizing exotic R4's using Kirby diagrams. method Provided Kirby diagrams for a family of exotic R4's constructed from specific knot complements. result Generalized Kirby diagrams for a broader family of exotic R4's. New exotic 4-manifolds with even b2+ and Z/2Z fundamental group.
problem Creating new exotic smooth structures on 4-manifolds with specific fundamental groups.
method Using double node surgery and rational blowdown constructions on elliptic fibrations with a free involution.
result Construction of infinitely many irreducible exotic smooth structures.
Construct non-split 2-component links in S4 to produce exotic pairs of 4-manifolds
problem Construct non-split 2-component links in S4 method Construct non-split 2-component links in S4 result Obtain exotic pairs of simply connected, definite 4-manifolds with boundary
We study the possibility of realizing exotic smooth structures on punctured simply connected 4-manifolds as leaves of a codimension one foliation on a compact manifold. In particular, we show the existence of uncountably many smooth open 4-manifolds which are not diffeomorphic to any leaf of a codimension one trans…
Study exotic phenomena in small 4-manifolds using diffeomorphisms.
problem Understanding exotic smooth structures and embeddings in 4-manifolds.
method Using constraints from Seiberg-Witten theory on diffeomorphisms.
result New methods to detect and bound exotic phenomena.
New definite 4-manifolds found with non-cyclic groups.
problem Finding exotic smooth structures on 4-manifolds with specific fundamental groups.
method Constructing infinitely many non-diffeomorphic structures.
result Infinitely many pairwise non-diffeomorphic definite 4-manifolds with Z/2imesZ/2 fundamental group. Study rules out exotic S4 and #nCP2 construction using zero surgery homeomorphisms.
problem Tackles the possibility of constructing exotic S4 or #nCP2 using zero surgery homeomorphisms. method Uses zero surgery homeomorphisms to relate slice properties of knots stably after a connected sum with a 4-manifold.
result Rules out the possibility of constructing exotic S4 or #nCP2 using zero surgery homeomorphisms. New methods distinguish exotic 4-manifolds using Heegaard Floer homology.
problem Distinguishing exotic 4-manifolds from standard ones.
method Using Heegaard Floer homology to define new invariants.
result New invariants remain distinct in covers and can distinguish exotic manifolds.
Detects exotic surfaces without smooth invariants, providing first example of knotted RP².
problem Detecting exotic surfaces without smooth invariants.
method Two versions of families (Seiberg-Witten) generalizations of Donaldson's diagonalization theorem.
result First example of exotically knotted RP² with diffeomorphic complements.
Exotic diffeomorphism survives stabilizations on a contractible 4-manifold.
problem Finding exotic diffeomorphisms on contractible 4-manifolds.
method Developed a Pin(2) × Z_2-equivariant refinement for computing Seiberg-Witten Floer homotopy types.
result Constructed an exotic diffeomorphism that survives two stabilizations.
Paper extends Miyazawa's construction to more 4-manifolds, finding exotic involutions and embeddings.
problem Finding exotic involutions and embeddings in 4-manifolds.
method Real Seiberg-Witten theory.
result Many infinite families of exotic involutions and embeddings.
Extends exotic embeddings of RP^2 to a larger family and produces homotopy spheres.
problem Constructing exotic embeddings of RP^2 and homotopy spheres.
method Using Montesinos knots and roll-spun knots to prove the existence of homotopy spheres.
result An infinite family of homotopy spheres and homotopy CP^2s are produced.
We construct potentially new manifolds homeomorphic but not diffeomorphic to CP2#8CP2 and CP2#9CP2 via rational blowdown surgery along certain 4-valent plumbing graphs. This way all the graph classes from \cite{weighted} have a represen…
Constructs Lefschetz fibrations on exotic 4-manifolds, providing bounds and equalities for singular fibers.
problem Constructing Lefschetz fibrations on exotic 4-manifolds with specific genus and singular fiber counts.
method Explicit construction of nonhyperelliptic and hyperelliptic Lefschetz fibrations of genus 4 on simply-connected 4-manifolds.
result Upper bounds and equality for the minimal number of singular fibers of Lefschetz fibrations, with specific results for higher genera.
Constructs exotic proper 2-knots from open 2-handles.
problem Proving topological equivalence of exotic proper knotted surfaces.
method Flexible construction of exotic open 2-handles, distinguishing through genus functions and end Floer homology.
result Constructs infinite families of irreducible exotic proper knotted surfaces.
In this paper we show that in some important cases 4-dimensional data can be extracted from superstring theory such that a) the data are 4 Euclidean geometries embedded in standard R4, b) these data depend on NS and D brane charges of some string backgrounds, c) it is of potential relevance to 4-dimension…
This paper extends T-duality to exotic chiral de Rham complexes.
problem Extending T-duality to new mathematical structures.
method Introducing exotic chiral de Rham complexes and isomorphisms.
result Established an isomorphism between chiral de Rham complexes.
New representation of PSL2(R) on infinite hyperbolic space via convex bodies.
problem Continuous irreducible actions of PSL2(R) on infinite-dimensional hyperbolic space.
method Using hyperbolic model for convex bodies, produce a continuous and irreducible representation.
result Yields a convex cocompact PSL2(R)-action on infinite-dimensional hyperbolic space with specific quotient properties.
Study finite group actions on exotic aspherical space forms.
problem Classify finite group actions on M#Σ where M is a closed aspherical space form and Σ is an exotic n-sphere. method Combines geometric and topological rigidity results with smoothing theory and spectral sequence computations.
result Classification of free actions of finite groups on M#Σ when M is 7-dimensional. This paper explores twisted Lagrangian tori in C^2 and their Hamiltonian stationarity.
problem Understanding the Hamiltonian stationarity of twisted Lagrangian tori in C^2.
method Investigation of differential geometry of twisted tori, including product and Chekanov's exotic tori.
result Only product tori are minimal under Hamiltonian deformations, indicating Chekanov's exotic tori are not area minimal.
We construct G-corks for any extension G of Zm by any finite subgroup of SO(4) and weakly equivariant G-corks for any extension G of Zm by any finite solvable group. In particular, this is the first example of G-corks for an infinite nonabelian group G and answers a question…
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.
In the paper we prove the existence of the strict but relative relation between small exotic R4 for a fixed radial family of DeMichelis-Freedman type, and cobordism classes of codimension one foliations of S3 distinguished by the Godbillon-Vey invariant, GV∈H3(S3,R) (represented b…
The paper studies exotic diffeomorphisms of 4-manifolds with b_+ = 2.
problem Examining exotic diffeomorphisms in 4-manifolds with a specific topological invariant.
method Utilizes Seiberg-Witten invariants for 1-parameter families of 4-manifolds and a gluing formula for connected sums.
result Proves that the mapping class group of certain 4-manifolds is not finitely generated and surjects to Z^∞.
We introduce the 2-nodal spherical deformation of certain singular fibers of genus 2 fibrations, and use such deformations to construct various examples of simply connected minimal symplectic 4-manifolds with small topology. More specifically, we construct new exotic minimal symplectic 4-manifolds homeomorphic …
Paper explores using 0-surgery to find exotic 4-manifolds.
problem Distinguishing smooth structures on 4-manifolds.
method Uses 0-surgery homeomorphisms to generate exotic pairs.
result Found 5 topologically slice knots potentially leading to exotic spheres.
In a recent paper of Akhmedov, Etnyre, Mark and Smith, it was shown that there exist infinitely many contact Seifert fibered 3-manifolds each of which admits infinitely many exotic (homeomorphic but pairwise non-diffeomorphic) simply-connected Stein fillings. Here we extend this result to a larger set of contact Seifer…
New invariants detect exotic smooth structures in 4-manifolds.
problem Detect exotic smooth structures in 4-manifolds using invariants of 2-handlebodies.
method Investigates invariants of 4-dimensional 2-handlebodies from the Temperley-Lieb category in positive characteristic.
result Height n=2 invariant vanishes on CP2, CP2, and S2imesS2 for p>3. We show that no exotic R4 admits a complete Riemannian metric with uniformly positive isotropic curvature and with bounded geometry. This is essentially a corollary of the main result in [Hu1], and was stated in [Hu2] without proof. In the process of the proof we also show that the diffeomorphism type of an…
New stable exotic 4-manifolds found with specific topological properties.
problem Identifying conditions for the existence of stable exotic 4-manifolds.
method Investigated fundamental group, Stiefel-Whitney classes, and H_5(π;Z) to determine stable exotic pairs.
result Produced new stable exotica and settings where they do not arise.
Introduces slice knots and concordance, linking to exotic smooth structures.
problem Understanding slice knots and their equivalence through concordance.
method Explains connections and introduces filtrations, satellite operations.
result Connections between slice knots and exotic smooth structures on \(\mathbb{R}^4\).
Classifies 4-manifolds with specific properties and fundamental group.
problem Classifying 4-manifolds with fundamental group Z and boundary. method Topological and smooth classification methods, including Hermitian forms and 2-handlebody constructions. result Every Hermitian form over Z[t±1] arises as the equivariant intersection form of exotic smooth 4-manifolds. We prove a general fusion theorem for complete orientable minimal surfaces in R3 with finite total curvature. As a consequence, complete orientable minimal surfaces of weak finite total curvature with exotic geometry are produced. More specifically, universal surfaces (i.e., surfaces from which all minimal …
Khovanov homology distinguishes exotic 4-manifolds.
problem Existence of exotic compact orientable 4-manifolds.
method Khovanov-Rozansky gl2 skein lasagna module and related invariants. result First analysis-free proof of exotic 4-manifolds.
The study creates symplectic Lefschetz fibrations and rational blowdowns for new 4-manifolds.
problem Creating symplectic Lefschetz fibrations and rational blowdowns for new 4-manifolds.
method Producing simply connected, minimal, symplectic Lefschetz fibrations and rationally blowing down Lefschetz fibrations with clustered nodal fibers.
result New constructions of small symplectic exotic 4-manifolds.
Classifies circle actions on 6D manifolds with 4 fixed points.
problem Classifying circle actions on 6D manifolds with specific fixed points.
method Analyzes fixed point data and proves agreement with known actions.
result Agrees with actions on 6-spheres or CP3. By using the relation between foliations and exotic R^4, orbifold K-theory deformed by a gerbe can be interpreted as coming from the change in the smoothness of R^4. We give various interpretations of integral 3-rd cohomology classes on S^3 and discuss the difference between large and small exotic R^4. Then we show t…
New hyperbolic groups exhibit unusual finiteness properties.
problem Finding groups with specific finiteness properties.
method Fibre product construction and homomorphisms to Z and Z2. result Examples of hyperbolic groups with kernels of type Fk but not Fk+1. We studied isometric stochastic flows of a Stratonovich stochastic differential equation on spheres, i.e. on the standard sphere and Gromoll-Meyer exotic sphere. The standard sphere Ss7 can be constructed as the quotient manifold Sp(2,H)/S3 with the so-called ∙-action of S3, where…