Goldman’s conjecture for type-preserving representations
For every punctured surface with , the mapping class group acts ergodically on every non-Teichmüller component of the relative -character variety of type-preserving representations.
References
Primary source
Additional references
Progress summary
A 2026 paper reduces a substantial part of the conjecture to another unresolved question, so neither conjecture is settled.
Goldman’s conjecture predicts ergodicity of the mapping class group action on appropriate character-space components for type-preserving representations. The related Bowditch question asks whether non-Fuchsian representations must send some simple closed curve to a non-hyperbolic element.
Known results
- Four-punctured sphere: ergodicity holds on every non-extremal component (Marché–Wolff, 2014).
- For , there are uncountably many non-Fuchsian examples with every non-peripheral simple closed curve hyperbolic (Marché–Wolff, 2014).
- For on the four-punctured sphere, some non-peripheral simple closed curve is elliptic or parabolic (Marché–Wolff, 2014).
- Souto proved Bowditch’s question for Euler-class-zero representations of closed surfaces of genus ; nonzero non-extremal cases remain open.
Recent reduction
A new paper proves that an affirmative answer to Bowditch’s question implies Goldman’s conjecture on components with fixed peripheral signs and non-extremal relative Euler classes satisfying the generalized Milnor–Wood inequality. This is a substantial reduction, not a solution of either conjecture, and the paper’s claim has not been independently verified here.
Current status (as of September 2026): A substantial conditional reduction is reported, but Bowditch’s question and Goldman’s conjecture remain open in general.
Sources
- arxiv.org
- arxiv.org
- deepmind.google
- quantamagazine.org
- scientificamerican.com
- quantamagazine.org
- en.wikipedia.org
- wiris.com
- quantamagazine.org
- arxiv.org
- ar5iv.labs.arxiv.org
- arxiv.org
- ar5iv.labs.arxiv.org
- export.arxiv.org
- mathstodon.xyz
- mathstodon.xyz
- mathstodon.xyz
- mathstodon.xyz
- mathstodon.xyz
- quantamagazine.org
- cdn.openai.com
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