Faber–Voloch conjecture on Newton approximation

About 10 years old · traced to

Let gg be a polynomial of degree d≥2d\geq 2 with coefficients in a number field KK, and let y0∈Ky_0\in K. Define the Newton map

N(z)=z−g(z)g′(z)N(z)=z-\frac{g(z)}{g'(z)}

and, for each n≥0n\geq 0, set yn+1=N(yn)y_{n+1}=N(y_n). Assume that the Newton approximation sequence (yn)(y_n) is not eventually periodic. Let C(K,g,y0)C(K,g,y_0) be the set of primes \fP\fP of KK for which (yn)(y_n) converges in the completion K\fPK_{\fP} to a root of ff. Faber–Voloch's conjecture. The natural density of the set C(K,g,y0)C(K,g,y_0) is zero. This conjecture predicts that, outside the eventually periodic case, Newton approximation converges \fP\fP-adically to a root for a density-zero set of primes. The source presents it as a conjecture motivating the choice of polynomial, and no resolution is supplied here.

References

Primary source

Robert L. Benedetto, Xander Faber, Benjamin Hutz, Jamie Juul and Yu Yasufuku, “A large arboreal Galois representation for a cubic postcritically finite polynomial”, arXiv:1612.03358 (2017).

Progress summary

Never refreshed

Nothing recorded yet. Refresh searches the literature and the public web for attempts on this problem, and writes the first summary here.

Solutions 0

No solutions have been posted yet.