Article collection "Mathematical Problems of Cybernetics" №4, Moscow, 1992
Authors:Kochergin V.V.
On the complexity of computations in finite Abelian groups
Abstract:
If G is a finite (multiplicitively written) Abelian group, a set of elements BG = {g1, . . . , gq} is called a basis of G if G is the product of the cyclic groups generated by g1, . . . , gq: G = бg1с× . . . × бgqс. Circuits for functional elements of multiplication, which for any two elements of G as input realize their product, are studied. The total number of elements of multiplication in such a circuit S is called the complexity L(S) of S. The complexity of any finite abelian group
G in the basis BG is defined as L(G, BG) = maxg∈G minS L(S), where the S are the circuits in the basis BG that realize g. The paper gives proofs of the following estimates as |G| → ∞:
L(G,BG) = (log2|G| / log2log2|G|) (1+O(√ (log2log2log2|G| / log2log2|G|))) +O(p+|BG|)
where p is the largest order of a basis element in BG; and
L(n) = log2n + (1 + o(1))(log2n / log2log2n)
for the corresponding Shannon function L(n) = maxG:|G|=nminBGL(G,BG).
En route, some estimates on the complexity of certain auxiliary binary step matrices by gate circuits (rectifier networks) are established.
Keywords:
finite Abelian group, gate circuit (rectifier network), circuit complexity, complexity of group, Shannon function
Kochergin Vadim Vasil'evich, vvkoch@yandex.ru, Механико-математический факультет МГУ, Кафедра дискретной математики, Институт теоретических проблем микромира им. Н. Н. Боголюбова МГУ