实二次代数整数环上的单位格的类数

Class Number of Unit Lattices Over Real Quadratic Integer Rings

用邻格方法及Siegel mass公式证明了实二次代数域(?)(d^(1/2))上单位格种gen(In)(n≥4)的类数h(In)=3当且仅当(?)(3^(1/2)):n=4;(?)(5^(1/2)):n=6;(?)(13^(1/2)):n:4;(?)(17^(1/2)):n=4.

Using generalized adjacent lattice methods and Siegel mass formula we get the following result: The class number h(In) of unit lattice In(n ≥4) over real quadratic field F is 3 if and only if F=(?)(3^(1/2)) : n = 4; F = (?)(5^(1/2)) : n = 6; F =(?)(13^(1/2)) : n = 4; F =(?)(17^(1/2)) : n = 4.