English
Related papers

Related papers: An exotic smooth structure on CP^2+6CP^2-bar

200 papers

We construct smooth manifolds with order two $\pi_1$ and even intersection forms which are irreducible, meaning they do not decompose into non-trivial connected sums. Their intersection forms being even implies that their universal covers…

Geometric Topology · Mathematics 2025-10-21 Mihail Arabadji , Porter Morgan

In $1961$, Mazur constructed a contractible, compact, smooth $4$-manifold with boundary which is not homeomorphic to the standard $4$-ball, using a $0$-handle, a $1$-handle and a $2$-handle. In this paper, for any integer $n\geq2,$ we…

Geometric Topology · Mathematics 2023-06-13 Geunyoung Kim

We construct series of examples of exotic smooth structures on compact locally symmetric spaces of noncompact type. In particular, we obtain higher rank examples, which do not support Riemannian metric of nonpositive curvature. The examples…

Differential Geometry · Mathematics 2014-10-01 Boris Okun

We initiate the study of exotic Dehn twists along 3-manifolds $\neq S^3$ inside $4$-manifolds, which produces the first known examples of exotic diffeomorphisms of contractible 4-manifolds, more generally of definite 4-manifolds, and exotic…

Geometric Topology · Mathematics 2024-04-02 Hokuto Konno , Abhishek Mallick , Masaki Taniguchi

We prove necessary and sufficient conditions for a smooth surface in a 4-manifold X to be pseudoholomorphic with respect to some almost complex structure on X. This provides a systematic approach to the construction of pseudoholomorphic…

Differential Geometry · Mathematics 2007-05-23 Christian Bohr

Despite spectacular advances in defining invariants for simply connected smooth and symplectic 4-dimensional manifolds and the discovery of effective surgical techniques, we still have been unable to classify simply connected smooth…

Geometric Topology · Mathematics 2007-05-23 Ronald Fintushel , Ronald J. Stern

We construct infinitely many smooth oriented 4-manifolds containing pairs of homotopic, smoothly embedded 2-spheres that are not topologically isotopic, but that are equivalent by an ambient diffeomorphism inducing the identity on homology.…

Geometric Topology · Mathematics 2019-08-07 Hannah R. Schwartz

We describe interrelations between a topology structure of closed manifolds (orientable and non-orientable) of the dimension $n\geq 4$ and the structure of the non-wandering set of regular homeomorphisms, in particular, Morse-Smale…

Dynamical Systems · Mathematics 2024-08-06 Elena Gurevich , Ilya Saraev

Here we discuss an example of topologically isotopic but smoothly non-isotopic pair of 2-spheres in a simply connected 4-manifold, which become smoothly isotopic after stabilizing by connected summing with S^2 x S^2.

Geometric Topology · Mathematics 2014-06-24 Selman Akbulut

We use Furuta's result, usually referred to as ``10/8-conjecture'', to show that for any compact 3-manifold $M$ the open manifold $M\times\r$ has infinitely many different smooth structures. Another consequence of Furuta's result is…

dg-ga · Mathematics 2008-02-03 Zarko Bizaca , John Etnyre

This paper builds one-cusped complex hyperbolic $2$-manifolds by an explicit geometric construction. Specifically, for each odd $d \ge 1$ there is a smooth projective surface $Z_d$ with $c_1^2(Z_d) = c_2(Z_d) = 6d$ and a smooth irreducible…

Geometric Topology · Mathematics 2025-12-05 Martin Deraux , Matthew Stover

In this article, we give new means of constructing and distinguishing closed exotic four-manifolds. Using Heegaard Floer homology, we define new closed four-manifold invariants that are distinct from the Seiberg--Witten and Bauer--Furuta…

Geometric Topology · Mathematics 2023-07-18 Adam Simon Levine , Tye Lidman , Lisa Piccirillo

We develop techniques to construct explicit symplectic Lefschetz fibrations over the 2-sphere with any prescribed signature and any spin type when the signature is divisible by 16. This solves a long-standing conjecture on the existence of…

Geometric Topology · Mathematics 2020-10-23 R. Inanc Baykur , Noriyuki Hamada

We point out that recent constructions of inequivalent smooth structures yield a manufacturing procedure of infinite sets of pairwise smoothly non-isotopic nullhomologous 2-tori and spheres inside a myriad of 4-manifolds. The corresponding…

Geometric Topology · Mathematics 2024-05-24 Rafael Torres

In this note we present a new definition of the 4-manifold admitting inequivalent symplectic structures constructed by McMullen-Taubes which leads to the identification of a new symplectic structure. We prove moreover that it is…

Geometric Topology · Mathematics 2007-05-23 Stefano Vidussi

We show that many spin 6-manifolds have the homotopy type but not the homeomorphism type of a Kaehler manifold. Moreover, for given Betti numbers, there are only finitely many deformation types and hence topological types of smooth complex…

Algebraic Geometry · Mathematics 2019-04-26 Stefan Schreieder , Luca Tasin

We show that, for any two orientable smooth open 4-manifolds $X_0,X_1$ which are homeomorphic, their cotangent bundles $T^*X_0,T^*X_1$ are symplectomorphic with their canonical symplectic structure. In particular, for any smooth manifold…

Symplectic Geometry · Mathematics 2012-09-17 Adam Knapp

In this article, we construct countably many mutually non-isotopic diffeomorphisms of some closed non simply-connected 4-manifolds that are homotopic to but not isotopic to the identity, by surgery along $\Theta$-graphs. As corollaries of…

Geometric Topology · Mathematics 2023-02-24 Tadayuki Watanabe

Here we draw a handlebody picture for the exotic CP^2 # 2(-CP^2) constructed by Akhmedov and Park.

Geometric Topology · Mathematics 2015-01-13 Selman Akbulut

We define family versions of the invariant of 4-manifolds with contact boundary due to Kronheimer and Mrowka and use these to detect exotic diffeomorphisms of 4-manifolds with boundary. Further, we show the existence of the first example of…

Geometric Topology · Mathematics 2024-08-16 Nobuo Iida , Hokuto Konno , Anubhav Mukherjee , Masaki Taniguchi