An analogue, for mo
dular abelian varieties
A, of a conjecture of
Watkins on elliptic curves over , woul
d say that
divi
des the mo
dular
degree, where
R is the rank of the Mor
dell-Weil group . We exhibit some numerical evi
dence for this. We examine various sources of factors of 2 in the mo
dular
degree, an
d the extent to which they are in
depen
dent. Assuming that a certain 2-a
dic Hecke ring is a local complete intersection, an
d is isomorphic to a Galois
deformation ring (a 2-a
dic ¡°
![]()
dn.com/content/image/1-s2.0-S0022314X12002703-si4.gif""/>¡± theorem), we show how the analogue of Watkins?s conjecture follows, un
der certain con
ditions on
A, exten
ding an
d correcting earlier work on the elliptic curve case.