Arithmetic cusp shapes are dense

Counting cusped hyperbolic 3-manifolds that bound geometrically

We show that the number of isometry classes of cusped hyperbolic $3$-manifolds that bound geometrically grows at least super-exponentially with their volume, both in the arithmetic and non-arithmetic settings.

Cusps of Picard modular surfaces

We determine the number of cusps of minimal Picard modular surfaces. The proof also counts cusps of other Picard modular surfaces of arithmetic interest. Consequently, for each N > 0 there are finitely many commensurability classes of nonuniform arithmetic lattices in SU(2, 1) that contain an N-cusped surface. We also discuss a higher-rank analogue.

Densities of Hyperbolic Cusp Invariants

We find that cusp densities of hyperbolic knots in the 3-sphere are dense in [0,0.6826...] and those of links are dense in [0,0.853...]. We define a new invariant associated with cusp volume, the cusp crossing density, as the ratio between the cusp volume and the crossing number of a link, and show that cusp crossing density for links is bounded above by 3.1263.... Moreover, there is a sequence of links with cusp crossing density approaching 3. The least upper bound for cusp crossing density remains an open question. For two-component hyperbolic links, cusp crossing density is shown to be dens…

Volumes of Picard modular surfaces

We show that the conjectural cusped complex hyperbolic 2-orbifolds of minimal volume are the two smallest arithmetic complex hyperbolic 2-orbifolds. We then show that every arithmetic cusped complex hyperbolic 2-manifold of minimal volume covers one of these two orbifolds. We also give all minimal volume manifolds that simultaneously cover both minimal orbifolds.

双曲4流形的尖点与可公度类

Cusps and Commensurability Classes of Hyperbolic 4-Manifolds

本文为算术双曲4流形的可公度类何时包含给定尖点类型的代表元提供判据，并首次给出无穷多个不含某些尖点类型的可公度类例子。

Cusp and $b_1$ growth for ball quotients and maps onto $\mathbb{Z}$ with finitely generated kernel

Let $M = \mathbb{B}^2 / Γ$ be a smooth ball quotient of finite volume with first betti number $b_1(M)$ and let $\mathcal{E}(M) \ge 0$ be the number of cusps (i.e., topological ends) of $M$. We study the growth rates that are possible in towers of finite-sheeted coverings of $M$. In particular, $b_1$ and $\mathcal{E}$ have little to do with one another, in contrast with the well-understood cases of hyperbolic $2$- and $3$-manifolds. We also discuss growth of $b_1$ for congruence arithmetic lattices acting on $\mathbb{B}^2$ and $\mathbb{B}^3$. Along the way, we provide an explicit example of a l…

极大尖点并不稠密

Maximal cusps are not dense

本文构造反例证明在满足解析条件的无限型黎曼曲面 Teichmüller 空间的 Bers 边界上极大尖点不稠密，并利用固定端邻域的拟共形形变证明相关子集具有流形结构。

On the number of ends of rank one locally symmetric spaces

Let Y be a noncompact rank one locally symmetric space of finite volume. Then Y has a finite number e(Y) > 0 of topological ends. In this paper, we show that for any natural number n, the Y with e(Y) \leq n that are arithmetic fall into finitely many commensurability classes. In particular, there is a constant c_n such that n-cusped arithmetic orbifolds do not exist in dimension greater than c_n. We make this explicit for one-cusped arithmetic hyperbolic n-orbifolds and prove that none exist for n \geq 30.

具有每个尖点截面的尖点传递4流形

Cusp-transitive 4-manifolds with every cusp section

论文证明每个闭合平坦3流形可作为具有尖点传递对称性的完整有限体积超几何4流形的尖点截面，并展示其平流形的稠密子集可作为尖点传递4流形的尖点截面。

Cusp shape and tunnel number

We show that the set of cusp shapes of hyperbolic tunnel number one manifolds is dense in the Teichmuller space of the torus. A similar result holds for tunnel number n manifolds. As a consequence, for fixed n, there are infinitely many hyperbolic tunnel number n manifolds with at most one exceptional Dehn filling. This is in contrast to large volume Berge knots, which are tunnel number one manifolds, but with cusp shapes converging to a single point in Teichmuller space.

素测地线的绕数

Windings of prime geodesics

本文针对一般带尖点双曲轨形提出测地线绕指定尖点的绕数新构造，证明算术曲面族中该绕数可由Rademacher符号表示，并结合自守形式谱理论得到闭本原有向测地线绕数分布的统计结果。