2508.00266
Finite index theorems for iterated Galois groups of preperiodic points for unicritical polynomials
Minsik Han, Thomas J. Tucker
correctmedium confidence
- Category
- Not specified
- Journal tier
- Strong Field
- Processed
- Sep 28, 2025, 12:57 AM
- arXiv Links
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Audit review
The uploaded paper proves that for f(x)=x^q+c with q a prime power, 0 not preperiodic, and β strictly preperiodic, the index [G∞:G∞(β)] is finite (Theorem 1.2) and reduces this to certifying that, for all large n, Gal(Kn(β)/Kn−1(β)) attains the full Kummer kernel (Cq)^{q^{n−1}} (Proposition 2.1) by producing primes satisfying Conditions R/U and a multi-branch independence criterion (Propositions 4.7 and 4.9, combined with Proposition 5.1 and Theorem 5.3) . By contrast, the candidate solution makes a crucial incorrect reduction: it replaces β by a periodic α=f^m(β) and claims the towers agree from level m onward, which is false in general, and it does not supply the paper’s precise Conditions R/U or eventual stability/irreducibility inputs. It also attributes the key prime construction to a different source (squarefree portrait primes) than the paper’s actual Proposition 3.1 mechanism. Thus the paper’s argument is correct and complete for its claims, while the model’s proof outline has a fundamental flaw and missing hypotheses.
Referee report (LaTeX)
\textbf{Recommendation:} minor revisions \textbf{Journal Tier:} strong field \textbf{Justification:} The paper gives a clean, unconditional finite-index theorem for arboreal representations of x\^q+c with strictly preperiodic basepoints, using eventual stability, a carefully crafted diophantine prime-construction, and Kummer-theoretic ramification control. The logical flow is sound and the results are significant within arithmetic dynamics. Minor revisions could improve exposition (explicit dependence of constants, a schematic of the argument, and small clarifications in the multi-branch independence step).