Let $G = \Gamma_0(N)$, $N \not\equiv 3 \pmod{4}$ and $g$ be
the group generated by the involution $z \mapsto -1/Nz$ of
the upper half plane. We determine the cohomology set $H^1(g,G)$
in terms of the class number of quadratic forms of discriminant
$-4N$.
Publié le : 2001-03-14
Classification:
Congruence subgroups of level $N$,
the involution,
cohomology sets,
binary quadratic forms,
class number of orders,
11F75
@article{1148393108,
author = {Ono, Takashi},
title = {On certain Cohomology Set for $\Gamma \_0(N)$},
journal = {Proc. Japan Acad. Ser. A Math. Sci.},
volume = {77},
number = {10},
year = {2001},
pages = { 39-41},
language = {en},
url = {http://dml.mathdoc.fr/item/1148393108}
}
Ono, Takashi. On certain Cohomology Set for $\Gamma _0(N)$. Proc. Japan Acad. Ser. A Math. Sci., Tome 77 (2001) no. 10, pp. 39-41. http://gdmltest.u-ga.fr/item/1148393108/