On CM abelian varieties over an imaginary quadratic field<br><br>


Abstract: In this talk, we will first show that a CM abelian variety
over a quadratic imaginary field <i>K</I> has to have dimension at least 
<i>h</i> --- the ideal class number of <i>K</i>. We classify the CM abelian
CM varieties of the dimension <i>h</i> over <i>K</i>. Finally, we associate
one or two `simplest' CM abelian varieties over <i>K</i> of dimension <i>h</i>
and prove their central <i>L</I>-value/derivative 
behaves amazingly well.