2,107 reputation
526
bio website mat.ulaval.ca/hchapdelaine/…
location Quebec city
age 36
visits member for 3 years, 8 months
seen 6 hours ago

Aug
11
comment On Severi's definition of the complementary correspondence
thanks for the answer.
Aug
11
accepted On Severi's definition of the complementary correspondence
Aug
11
comment On Severi's definition of the complementary correspondence
So if we think of $T:C\rightarrow C$ as a multivalued function and $T(P)=\sum_{i} [P_i]$ (formal sum) then are you saying that $(-T)(P)=\sum_{i} [-P_i]$?
Aug
11
asked On Severi's definition of the complementary correspondence
Aug
7
accepted Explicit formula for the Poincare dual of a CM endomorphism of an elliptic curve
Aug
7
comment Explicit formula for the Poincare dual of a CM endomorphism of an elliptic curve
Yes you are right! So this solves my question. Many thanks!
Aug
6
comment Explicit formula for the Poincare dual of a CM endomorphism of an elliptic curve
Hi @Will. I agree with everything you said except that I don't quite see why $\Delta\cdot\Gamma$ corresponds to $[(1-\sqrt{-D})^{-1}\mathcal{O}_K:\mathcal{O}_K]$
Aug
6
comment Explicit formula for the Poincare dual of a CM endomorphism of an elliptic curve
I thought a bit a bout my problem and now I realized that the way I set it up is probably not ideal. It is probably better to work with homology since then one can make pictures. The group $H_2(E,\mathbf{Z})$ has $3$ natural $\mathbf{Z}$-linearly independant elements, namely $E_1=E\times\{0\}$, $E_2=\{0\}\times E$ and $\Delta$ (the diagonal). Intuitively we should have $E_2\cdot \Gamma=1$ and $E_1\cdot\Gamma=D$. Though the intersection $\Delta\cdot \Gamma$ seems to be more complicated to compute.
Aug
6
revised Explicit formula for the Poincare dual of a CM endomorphism of an elliptic curve
added 114 characters in body
Aug
6
revised Explicit formula for the Poincare dual of a CM endomorphism of an elliptic curve
added 447 characters in body
Aug
6
asked Explicit formula for the Poincare dual of a CM endomorphism of an elliptic curve
Jul
19
comment General criterion to find a Z-basis in a fixed generating subset
Thanks, now I think I see how to prove it. The point is that multiplication on the left or the right by an invertible matrix with coefficients is Z preserves the determinant of the $k\times k$ minors.
Jul
19
accepted General criterion to find a Z-basis in a fixed generating subset
Jul
18
revised General criterion to find a Z-basis in a fixed generating subset
added 232 characters in body
Jul
18
comment General criterion to find a Z-basis in a fixed generating subset
no, I really meant what I wrote.
Jul
18
asked General criterion to find a Z-basis in a fixed generating subset
Jul
18
awarded  Popular Question
Jul
15
comment minimal conductors among elliptic curves with a fixed CM type
Thanks for the data. Yes my questions are closely related to asking for a "canonical Grossencharacter" of a quadratic CM field, but from what you say it seems that such an object does not really exist.
Jul
15
asked minimal conductors among elliptic curves with a fixed CM type
Jul
15
comment On the conductor of the Groessencharacter of a CM elliptic curve
So the point is as @Cesnavicius wrote, the support of the conductor won't be bounded.