# Imaginary quadratic field data (2013 updates)

## Numbers of newforms (rational, cuspidal, weight 2)

These counts are expected to equal the number of isogeny classes of elliptic
curves defined over the field $K$ in question with conductor equal to the level of
the newform, with two provisos:
- Elliptic curves with CM by an order in $K$ will not be counted. These are
characterised as those curves having specific $j$-invariants, as listed.
(These $j$-invariants my be listed using the Sage command
`cm_j_invariants_and_orders(QQ)`)
- Newforms which are base-changes of newforms over Q with extra twist may
not have associated elliptic curves defined over $K$: see
*Abelian Varieties with Extra Twist, Cusp Forms, and Elliptic Curves Over Imaginary Quadratic Fields*

Journal
of the London Mathematical Society 45 (1992) 402-416

For each field (currently just the five Euclidean fields) we give

- basic data about the field, specifically the primes of norm ${}<1000$ in
standard order (norm, label, characteristic, degree, ramification
degree);
- a list giving the number of rational weight 2 newforms at each level in
some range;
- a list of these newforms $F$ (label, level, sign of functional equation of
$L(F,s)$, ratio $L(F,1)/\Omega\in\mathbb{Q}$ showing whether or not $L(F,1)=0$,
Atkin-Lehner
eigenvalues, first 25 Fourier coefficients $a_{\mathfrak{p}}$ indexed by all
prime ideals in standard order).

- $\mathbb{Q}(\sqrt{-1})$: field data;
exceptional CM $j$-invariants: 1728, 287496.

counts for levels of norm ${}<10^4$,
rational newforms of levels of norm
${}<10^4$.
- $\mathbb{Q}(\sqrt{-2})$: field data;
exceptional CM $j$-invariant: 8000.

counts for levels of norm ${}<10^4$,
rational newforms of levels of norm
${}<10^4$.
- $\mathbb{Q}(\sqrt{-3})$: field data;
exceptional CM $j$-invariants: 0, 54000, -12288000.

counts for levels of norm ${}<10^4$,
rational newforms of levels of norm
${}<10^4$.
- $\mathbb{Q}(\sqrt{-7})$: field data;
exceptional CM $j$-invariants: -3375, 16581375.

counts for levels of norm ${}<10^4$,
rational newforms of levels of norm
${}<10^4$.
- $\mathbb{Q}(\sqrt{-11})$: field data;
exceptional CM $j$-invariant: -32768.

counts for levels of norm ${}<10^4$,
rational newforms of levels of norm
${}<10^4$.

Plain text index of ancient data