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CaTherine wheels
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The pith
CaTherine wheels unify structures across fields by providing a canonical bijection between orbit-equivalence classes of pseudo-Anosov flows without perfect fits, G-equivariant CaTherine wheels, minimal G-zippers, and connected components of uniform quasimorphisms for the fundamental group of any闭ed
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
Core claim
If M is a closed hyperbolic 3-manifold and G=π1(M), we show that there is a canonical bijection between four kinds of structures associated to M: 1. orbit-equivalence classes of pseudo-Anosov flows on M without perfect fits; 2. G-equivariant CaTherine wheels up to conjugacy; 3. minimal G-zippers; and 4. connected components of the space of uniform quasimorphisms on G.
Load-bearing premise
The definitions of CaTherine wheels and the associated structures (pseudo-Anosov flows without perfect fits, minimal G-zippers) are well-posed and that the canonical bijection exists for every closed hyperbolic 3-manifold without further restrictions on the manifold or the flows.
Figures
read the original abstract
A CaTherine wheel is a surjective continuous map $f:S^1 \to S^2$ such that for every closed interval $I\subset S^1$ the image $f(I)$ is homeomorphic to a disk, and $f(\partial I)$ is contained in the boundary of this disk. CaTherine wheels arise in many areas of low-dimensional geometry and topology, including conformal dynamics (expanding Thurston maps, expanding origamis), probability theory (whole plane ${\rm SLE}_\kappa$ for $\kappa \ge 8$, LQG metric trees) and elsewhere. We develop their theory in generality, and explain how CaTherine wheels and their associated structures can serve as a dictionary between these various fields. Our most substantial applications are to the theory of hyperbolic 3-manifolds. If $M$ is a closed hyperbolic 3-manifold and $G=\pi_1(M)$, we show that there is a canonical bijection between four kinds of structures associated to $M$: 1. orbit-equivalence classes of pseudo-Anosov flows on $M$ without perfect fits; 2. $G$-equivariant CaTherine wheels up to conjugacy; 3. minimal $G$-zippers; and 4. connected components of the space of uniform quasimorphisms on $G$. This generalizes and amplifies the theory of fiberings of hyperbolic 3-manifolds over the circle and the Thurston norm.
Editorial analysis
A structured set of objections, weighed in public.
Axiom & Free-Parameter Ledger
axioms (1)
- standard math Standard axioms of point-set topology and manifold theory (continuous maps, homeomorphisms, fundamental groups)
invented entities (1)
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CaTherine wheel
no independent evidence
Forward citations
Cited by 2 Pith papers
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Convex Hull Volumes in Hyperbolic 3-Space
A geometric condition on closed subsets of the Riemann sphere implies that their hyperbolic convex hulls in H^3 have infinite volume, with corollaries characterizing continua and planar self-similar sets with this property.
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Convex Hull Volumes in Hyperbolic 3-Space
A geometric condition on closed subsets of the Riemann sphere implies that their hyperbolic convex hulls in H^3 have infinite volume, yielding characterizations of continua and planar self-similar sets.
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