Exotic Smooth Structures on Small 4-Manifolds with Odd Signatures

Exotic smooth structures on 4-manifolds with zero signature

For every integer $k\geq 2$, we construct infinite families of mutually nondiffeomorphic irreducible smooth structures on the topological $4$-manifolds $(2k-1)(S^2\times S^2)$ and $(2k-1)(\CP#\CPb)$, the connected sums of $2k-1$ copies of $S^2\times S^2$ and $\CP#\CPb$.

具有奇数 $b_+$ 的可约 $4$ 流形的奇异微分同胚

Exotic diffeomorphisms of reducible $4$-manifolds with odd $b_+$

利用族Bauer-Furuta不变量，在具有奇数$b_+$的可约$4$流形上构造奇异微分同胚，并发现映射类群非有限生成的单连通$4$流形新例子。

$E_8$-plumbings and exotic contact structures on spheres

We prove the existence of exotic but homotopically trivial contact structures on spheres of dimension 8k-1. Together with previous results of Eliashberg and the second author this establishes the existence of such structures on all odd-dimensional spheres (of dimension at least 3).

签名零的奇异4-流形

Exotic 4-manifolds with signature zero

我们构造了无穷多个签名零的极小辛奇异4-流形，它们同胚于特定的连通和，且是迄今最小的此类流形，方法基于映射类群正分解的特殊 Lefschetz 纤维化。

A splitting formula for the spectral flow of the odd signature operator on 3-manifolds coupled to a path of SU(2) connections

We establish a splitting formula for the spectral flow of the odd signature operator on a closed 3-manifold M coupled to a path of SU(2) connections, provided M = S cup X, where S is the solid torus. It describes the spectral flow on M in terms of the spectral flow on S, the spectral flow on X (with certain Atiyah-Patodi-Singer boundary conditions), and two correction terms which depend only on the endpoints. Our result improves on other splitting theorems by removing assumptions on the non-resonance level of the odd signature operator or the dimension of the kernel of the tangential operator,…

Index type invariants for twisted signature complexes and homotopy invariance

For a closed, oriented, odd dimensional manifold $X$, we define the rho invariant $ρ(X,E,H)$ for the twisted odd signature operator valued in a flat hermitian vector bundle $E$, where $H = \sum i^{j+1} H_{2j+1}$ is an odd-degree closed differential form on $X$ and $H_{2j+1}$ is a real-valued differential form of degree ${2j+1}$. We show that the twisted rho invariant $ρ(X,E,H)$ is independent of the choice of metrics on $X$ and $E$ and of the representative $H$ in the cohomology class $[H]$. We establish some basic functorial properties of the twisted rho invariant. We express the twisted eta …