Quillen–Lichtenbaum conjecture

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Template:Short description In mathematics, the Quillen–Lichtenbaum conjecture is a conjecture relating étale cohomology to algebraic K-theory introduced by Template:Harvtxt, who was inspired by earlier conjectures of Template:Harvtxt. Template:Harvtxt and Template:Harvtxt proved the Quillen–Lichtenbaum conjecture at the prime 2 for some number fields. Voevodsky, using some important results of Markus Rost, proved the Bloch–Kato conjecture, which implies the Quillen–Lichtenbaum conjecture for all primes.

Statement

The conjecture in Quillen's original form states that if A is a finitely-generated algebra over the integers and l is prime, then there is a spectral sequence analogous to the Atiyah–Hirzebruch spectral sequence, starting at

E2pq=Hetalep(Spec A[1],Z(q/2)), (which is understood to be 0 if q is odd)

and abutting to

KpqAZ

for −p − q > 1 + dim A.

K-theory of the integers

Assuming the Quillen–Lichtenbaum conjecture and the Vandiver conjecture, the K-groups of the integers, Kn(Z), are given by:

  • 0 if n = 0 mod 8 and n > 0, Z if n = 0
  • Z ⊕ Z/2 if n = 1 mod 8 and n > 1, Z/2 if n = 1.
  • Z/ckZ/2 if n = 2 mod 8
  • Z/8dk if n = 3 mod 8
  • 0 if n = 4 mod 8
  • Z if n = 5 mod 8
  • Z/ck if n = 6 mod 8
  • Z/4dk if n = 7 mod 8

where ck/dk is the Bernoulli number B2k/k in lowest terms and n is 4k − 1 or 4k − 2 Template:Harv.

References