English

Notion de $\theta$-r\'egulateurs d'un nombre alg\'ebrique. Conjectures p-adiques

Number Theory 2021-08-09 v3

Abstract

Let K/Q be a Galois extension of degree n, of Galois group G, and let ηK×\eta\in K^\times. For all large enough prime p, we define, by use of the Frobenius theorem on group determinants, the family (Δpθ(η)\Fp)θ(\Delta_p^\theta(\eta) \in \F_p)_\theta of local θ\theta-regulators of η\eta, indexed by the Qp-irreducible characters θ\theta of G. At each Δpθ(η)\Delta_p^\theta (\eta) is associated a linear representation LθδVθL^\theta \simeq \delta V_\theta, 0δφ(1)0 \leq \delta \leq \varphi(1), which characterizes some properties of Δpθ(η)\Delta_p^\theta (\eta), including its nullity equivalent to δ1\delta \geq 1 (Th. 3.11). When η\Q×\eta \in \Q^\times and θ=1\theta = 1, Δp1(η)\Delta_p^1 (\eta) is the p-Fermat quotient of η\eta. When η\eta is a "Minkowski unit", each Δpθ(η)\Delta_p^\theta (\eta), θ1\theta \ne 1, gives the residue modulo p of the θ\theta-component of p1nRegp(K)p^{1-n} Reg_p (K), where Reg(K) is the classical p-adic regulator of K. We suggest that the "probability" of (Δpθ(η)=0\Delta_p^\theta(\eta) = 0 and LθδVθL^\theta \simeq \delta V_\theta) is O(1)pfδ2\frac{O(1)}{p^{f \delta^2}}, where f is a suitable residue degree of p. We conjecture that p1nRegp(K)p^{1-n} Reg_p(K), which measures the order of the p-torsion group in Abelian p-ramification over K, is for p large enough a p-adic unit except perhaps for a set of prime numbers of zero density. For these cases said "of minimal p-divisibility" (Def. 3.17), it remains possible, η\eta being then a "partial local pth power" at p, to propose, in connection with the ABC conjecture, a stronger conjecture leading to the same conclusion for all large enough p (Section 7). Some other conjectural aspects on the Fermat quotient are discussed. We precise and verify these properties through numerical studies on various fields and publish the corresponding "PARI" programs.

Keywords

Cite

@article{arxiv.1401.6890,
  title  = {Notion de $\theta$-r\'egulateurs d'un nombre alg\'ebrique. Conjectures p-adiques},
  author = {Georges Gras},
  journal= {arXiv preprint arXiv:1401.6890},
  year   = {2021}
}

Comments

Addition of 4.6. Improvement of some technical proofs (e.g. 3.2.1), minor corrections of statements in conjectures of 7.3, in French