Bhargava's ramification-density conjecture for SnS_n-number fields

Let nn be a positive integer and let B>0B>0. Let Gn(B)\mathcal{G}_{n}(B) be the collection of SnS_n-number fields KK with DKB|D_K|\leq B. For a prime pp, let Gn(B;p)\mathcal{G}_{n}(B;p) be the collection of degree-nn number fields satisfying: (p)(p) is unramified in KK, DKB|D_K|\leq B, and the normal closure of K/QK/\mathbb{Q} has Galois group SnS_n. Let q(k,n)q(k,n) denote the number of partitions of kk into at most nn parts, with q(0,n)=1q(0,n)=1 for n1n\geq 1, and define

ρn(p):=k=1n1q(k,nk)pn1kk=0n1q(k,nk)pn1k.\rho_n(p):=\frac{\sum_{k=1}^{n-1}q(k,n-k)p^{n-1-k}}{\sum_{k=0}^{n-1}q(k,n-k)p^{n-1-k}}.

Bhargava's ramification-density conjecture. For every prime pp and positive integer nn,

limB#{KGn(B;p)}#{KGn(B)}=1ρn(p).\lim_{B\rightarrow\infty}\frac{\#\{K\in\mathcal{G}_n(B;p)\}}{\#\{K\in\mathcal{G}_n(B)\}}=1-\rho_n(p).

Here ρn(p)\rho_n(p) is the predicted probability of ramification at pp. Bhargava proves the conjecture for n5n\leq 5; the assertion remains conjectural for general nn.

Sources & referencesView supporting material

Primary source

Jeffrey C. Lagarias and Benjamin L. Weiss, “Splitting Behavior of S_n-Polynomials”, arXiv:1408.6251 (2015).

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.