Finiteness of Anosov and pseudo-Anosov flows on hyperbolic 3-manifolds

We study the geography of taut foliations on compact $3$-manifolds with toroidal boundary components. The central object of our work is the set of boundary multislopes realized by foliations transverse to a fixed flow on such a manifold. We prove that these sets exhibit remarkable structural properties (rationality, rigidity, and convexity) which motivate the name ziggurats. Our main tool, of independent interest, is a two-way correspondence between foliations and contact structures on $3$-manifolds with boundary: we generalize the Eliashberg-Thurston theorem, which produces pairs of positive and negative contact structures from foliations, and a construction of the first author, which builds foliations from such contact pairs. Using both directions of this correspondence, we bring contact-geometric methods to bear on the architecture of ziggurats.

math.GT↗

arXiv2026

Lens spaces that cannot be obtained by two integral surgeries

In this article, we demonstrate that there exists an infinite family of lens spaces L(p,q) that cannot be obtained from the 3-sphere by two integral surgeries. The first such lens space in our family is L(177,29).

math.GT↗

arXiv2026

Which Immersions into Euclidean Space are Boundary Immersions?

Here we study the problem of whether a given codimension one immersion $f$ of a closed and connected manifold into Euclidean space can be extended to an equidimensional immersion $F$ of some compact manifold $M$ whose restriction to the boundary parameterizes the image $S$ of $f$. Such an extension $F$ exists if and only if (i) simple conditions on orientations and wrapping numbers are satisfied and (ii) a distinguished finite subset of the first cohomology of $S$ with coefficients in a certain sheaf of finite groups contains the preferred point.

math.GT↗