Potential density of integral points in relative character varieties

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Let YY be a smooth complex variety equipped with a smooth projective simple normal crossings compactification Y‾\overline{Y}, and let D=Y‾∖YD=\overline{Y}\setminus Y have components D1,…,DnD_1,\ldots,D_n. Let GG be a Chevalley group over Z\mathbb{Z}, let KK be a number field with ring of integers OK\mathscr{O}_K, and let XG,C‾(Y)X_{G,\underline{C}}(Y) denote the relative character variety of representations of π1(Y)\pi_1(Y) into GG whose local monodromy around each DiD_i has prescribed image CiC_i in (G/ad⁡G)(OK)(G/_{\operatorname{ad}}G)(\mathscr{O}_K), where C‾=(Ci)i=1,…,n\underline{C}=(C_i)_{i=1,\ldots,n}. Fix

C‾∈(G/ad⁡G)(OK)n.\underline{C}\in (G/_{\operatorname{ad}}G)(\mathscr{O}_K)^n.

Potential-density conjecture. Integral points are potentially Zariski-dense in the KK-scheme XG,C‾(Y)KX_{G,\underline{C}}(Y)_K: there exists a finite extension L/KL/K such that the Zariski closure of the OL\mathscr{O}_L-points of XG,C‾(Y)X_{G,\underline{C}}(Y) contains XG,C‾(Y)KX_{G,\underline{C}}(Y)_K.

The conjecture predicts arithmetic largeness of relative character varieties with fixed boundary monodromy, generalizing the paper's evidence from the case of SL⁡2\operatorname{SL}_2 and using a reduction to Riemann surfaces together with mapping-class-group dynamics. Its general validity for Chevalley groups and arbitrary smooth quasi-projective varieties remains open.

References

Primary source

Simone Coccia and Daniel Litt, “Density of integral points in the Betti moduli of quasi-projective varieties”, arXiv:2507.00167 (2025).

Additional references

3 papers in this index state this conjecture (2004–2025). The statement above is taken from the most recent of them; the others are arXiv:2404.17185, arXiv:math/0410558.

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Solutions 1

RemarkAI-assistedClaimed by OpenAI. Potential Zariski density of integral points on SL_r character varieties of smooth complex curves, after a finite number-field extension. The relative case covers prescribed boundary characteristic polynomials with roots of unity. This is a curve and SL_r subcase with quasi-unipotent boundary data; it does not cover arbitrary groups, higher-dimensional varieties or boundary data.See full solutionHide full solution

Claimed by OpenAI.

The manuscript claims potential Zariski density of integral points for SL_r character varieties of smooth connected complex curves, in every rank, after one finite number-field extension. For the relative problem it covers prescribed boundary characteristic polynomials whose roots are roots of unity. Such fixed adjoint-quotient boundary invariants define a closed relative fiber, so the manuscript's ambient integral points satisfying them are integral points of that fiber. This addresses the SL_r curve subcase with quasi-unipotent boundary data; arbitrary Chevalley groups, higher-dimensional varieties and arbitrary integral boundary data are outside the stated claim.

GitHub repository: https://github.com/openai/math

Manuscript: https://github.com/openai/math/blob/adc7f1241b42e322a6451854ab7e4b4c146bf78a/preprints/Integral-points-on-character-varieties-of-curves-September-25-2026/paper.pdf

  • OpenAI-027-01-Integral-points-on-character-varieties-of-curves.pdf466,173 bytesOpen