Math 2.0

Number theory Conjecture

Zagier's conjecture on polylogarithms

Builds on PolylogarithmBernoulli numberDedekind zeta functionAlgebraic number fieldDiscriminant of a number field

Statement

Let FF be an algebraic number field with r1r_1 real embeddings, r2r_2 pairs of complex conjugate non-real embeddings and discriminant dFd_F, and let m≥2m \ge 2. Let dm=r1+r2d_m = r_1 + r_2 if mm is odd and dm=r2d_m = r_2 if mm is even. Let σ1,…,σdm\sigma_1, \ldots, \sigma_{d_m} be the embeddings F→ℂF \to \C consisting of one from each complex pair, together with the real embeddings when mm is odd. Let Li⁡k\operatorname{Li}_k be the polylogarithm of order kk. Zagier's single-valued polylogarithm Lm ⁣:ℂ→ℝL_m \colon \C \to \R is Lm(z)=ℜm(∑k=0m−12kBkk!(log⁡∣z∣)kLi⁡m−k(z))(∣z∣≤1).L_m(z) = \Re_m \Big( \sum_{k=0}^{m-1} \frac{2^k B_k}{k!} (\log \abs{z})^k \operatorname{Li}_{m-k}(z) \Big) \quad (\abs{z} \le 1). It extends to a continuous function on ℂ\C with Lm(1/z)=(−1)m−1Lm(z)L_m(1/z) = (-1)^{m-1} L_m(z) for z≠0z \ne 0. Here ℜm\Re_m is the real part for mm odd and the imaginary part for mm even. The BkB_k are the Bernoulli numbers, with B1=−1/2B_1 = -1/2. Extend LmL_m additively to the free abelian group ℤ[F]\Z[F] on the elements of FF. Then there are ξ1,…,ξdm∈ℤ[F]\xi_1, \ldots, \xi_{d_m} \in \Z[F] and q∈ℚ×q \in \Q^\times with ζF(m)=q πe∣dF∣det⁡(Lm(σj(ξi)))1≤i,j≤dm,\zeta_F(m) = q \, \frac{\pi^{e}}{\sqrt{\abs{d_F}}} \det\big(L_m(\sigma_j(\xi_i))\big)_{1 \le i, j \le d_m}, where e=mr2e = m r_2 for mm odd and e=m(r1+r2)e = m(r_1 + r_2) for mm even, and ζF\zeta_F is the Dedekind zeta function.

Remarks

Zagier's conjecture is sharper than this existence statement. He defined subgroups ℬm(F)\mathcal{B}_m(F) of ℤ[F]\Z[F] by conditions that generalise the Bloch group, and conjectured that the ξi\xi_i can be taken in ℬm(F)\mathcal{B}_m(F). He also conjectured that LmL_m on these groups computes the Borel regulator on K2m−1(F)K_{2m-1}(F).

For m=2m = 2, L2L_2 is the Bloch–Wigner function, and the conjecture follows from Borel's theorem and the work of Bloch and Suslin; see dilogarithm and K3. Goncharov proved the case m=3m = 3. For F=ℚF = \Q and mm odd, Lm(1)=ζ(m)L_m(1) = \zeta(m), so the formula holds with ξ1=[1]\xi_1 = [1], q=1q = 1 and e=0e = 0.

Reading path

To understand this page from the ground up, read these 6 pages in order. The foundations come first.

Show the path as a graph
Each page uses the pages above it. The colour of the bar on a box shows how strong the evidence is, and the box also gives it as text. The list has the same pages.
  • no evidence level
  1. Algebraic number field concept
  2. Bernoulli number concept
  3. Dedekind zeta function concept
  4. Discriminant of a number field concept
  5. Polylogarithm concept
  6. Zagier's conjecture on polylogarithms conjecture

Further reading

  1. Web https://en.wikipedia.org/wiki/Polylogarithm
About this page
Tag3ZAPNS8QNV
URIm2://3ZAPNS8QNV
Kindconjecture
WritingW0 stub
MSC11G55, 11R42, 19F27
StatusThis copy of the site has no build data. Run m2 status 3ZAPNS8QNV.
AboutPolylogarithm, Dedekind zeta function
UsesPolylogarithm, Bernoulli number, Dedekind zeta function, Algebraic number field, Discriminant of a number field
Changed3 November 2026

Markdown · JSON · Edit on GitHub

What this page needs for W1

  • an inventory row: the row of the inventory that the node accounts for (0 of 1)
  • a source with a locator (0 of 1)

The writing levels say how complete the text of a page is. They do not measure its truth.

What links here

No page links to this page yet.