Exotic projective structures and quasifuchsian spaces II

Exotic components in linear slices of quasi-Fuchsian groups

The linear slice of quasi-Fuchsian once-punctured torus groups is defined by fixing the complex length of some simple closed curve to be a fixed positive real number. It is known that the linear slice is a union of disks, and it always has one standard component containing Fuchsian groups. Komori and Yamashita proved that there exist non-standard components if the length is sufficiently large. We give two other proofs of their theorem, one is based on some properties of length functions, and the other is based on the theory of complex projective structures and complex earthquakes. From the lat…

Surgery along star shaped plumbings and exotic smooth structures on 4-manifolds

We define a new 4-dimensional symplectic cut and paste operation which is analogous to Fintushel and Stern's rational blow-down. We use this operation to produce multiple constructions of symplectic smoothly exotic complex projective space blown-up eight times, seven times, and six times. We also show how this operation can be used in conjunction with knot surgery to construct an infinite family of minimal exotic smooth structures on the complex projective space blown-up seven times.

Farrell-Jones spheres and inertia groups of complex projective spaces

We introduce and study a new class of homotopy spheres called Farrell-Jones spheres. Using Farrell-Jones sphere we construct examples of closed negatively curved manifolds $M^{2n}$, where $n=7$ or $8$, which are homeomorphic but not diffeomorphic to complex hyperbolic manifolds, thereby giving a partial answer to a question raised by C.S. Aravinda and F.T. Farrell. We show that every exotic sphere not bounding a spin manifold (Hitchin sphere) is a Farrell-Jones sphere. We also discuss the relationship between inertia groups of $\mathbb{C}\mathbb{P}^n$ and Farrell-Jones spheres.

具有指定基本群的奇异不可定向四维流形

Exotic non-orientable four-manifolds with prescribed fundamental group

本文证明具有指数2子群的有限表示群可作为闭光滑不可定向四维流形的基本群，该流形通过Gluck扭结获得奇异光滑结构，其定向2-覆盖微分同胚，且两种结构在添加不同流形后表现出不等价与稳定化特性。

Convex projective manifolds with a cusp of any non-diagonalizable type

Recent work of Ballas, Cooper, and Leitner identifies $(n+1)$ types of $n$-dimensional convex projective cusps, one of which is the standard hyperbolic cusp. Work of Ballas-Marquis, and Ballas-Danciger-Lee give examples of these exotic (non-hyperbolic) type cusps in dimension $3$. Here an extension of the techniques of Ballas-Marquis shows the existence of all cusp types in all dimensions, except diagonalizable (type $n$).

奇异圆盘与奇异瞬子Floer同调

Exotic disks and singular instanton Floer homology

利用带Chern-Simons滤波的奇异瞬子Floer同调构造奇异切片圆盘对，并证明存在强可逆Z-切片纽结，其任意对称Z-圆盘对均为奇异且稳定后仍奇异。