On Gauss’s class number problems
- 1 January 1969
- journal article
- Published by American Mathematical Society (AMS) in Mathematics of Computation
- Vol. 23 (105) , 151-163
- https://doi.org/10.1090/s0025-5718-1969-0262204-1
Abstract
Let h h be the class number of binary quadratic forms (in Gauss’s formulation). All negative determinants having some h = 6 n ± 1 h = 6n \pm 1 can be determined constructively: for h = 5 h = 5 there are four such determinants; for h = 7 h = 7 , six; for h = 11 h = 11 , four; and for h = 13 h = 13 , six. The distinction between class numbers for determinants and for discriminants is discussed and some data are given. The question of one class/genus for negative determinants is imbedded in the larger question of the existence of a determinant having a specific Abelian group as its composition group. All Abelian groups of order > 25 > 25 so exist, but the noncyclic groups of order 25, 49, and 121 do not occur. Positive determinants are treated by the same composition method. Although most positive primes of the form n 2 − 8 {n^2} - 8 have h = 1 h = 1 , an interesting subset does not. A positive determinant of an odd exponent of irregularity also appears in the investigation. Gauss indicated that he could not find one.Keywords
This publication has 3 references indexed in Scilit:
- Some number-theoretic calculationsJournal of Research of the National Bureau of Standards Section B Mathematics and Mathematical Physics, 1965
- Note on Irregular DeterminantsJournal of the London Mathematical Society, 1936
- Heilbronn’s class-number theoremProceedings of the Indian Academy of Sciences - Section A, 1934