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bio website people.brandeis.edu/~jbellaic
location Stony Creek, États-Unis
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visits member for 4 years
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Professor of Mathematics at Brandeis University


1d
awarded  Nice Answer
2d
answered Examples of intuition from fields other than Physics to solve math problems
2d
comment Examples of intuition from fields other than Physics to solve math problems
That's a good example. +1.
2d
awarded  Yearling
Sep
15
reviewed Approve suggested edit on Is it easy to prove that $\sum_n |X(\mathbb{F}_{q^n})| t^n$ is rational?
Sep
12
comment Is Gauss sum a p-adic measure?
Dear user57657, can you please write down the formula defining $G(\chi)$ to ensure that everyone understands the same thing with this notation?
Sep
11
comment multiplicity of automorphic representation of unitary similitude group
In the case where $\pi$ admits a cuspidal base change, I would think that the multiplicity is 1. I am not completely sure because the these Harris-Taylor unitary groups are not the one I ma familiar with, but for the groups I work with Chenevier in my book "Families of Galois Representations and Selmer Groups". I know that's true.
Sep
11
comment Field of definition of Galois representations of weight 1 modular forms
Hi David. What is the LMFDB?
Sep
11
revised Field of definition of Galois representations of weight 1 modular forms
edited tags
Sep
11
answered Field of definition of Galois representations of weight 1 modular forms
Sep
7
answered Understanding the “idea” behind Langlands
Sep
4
comment Sheaf isomorphism $\mathcal{F}\rightarrow f_{\ast}f^{\ast}(\mathcal{F})$?
I don't understand the notations. You are talking of sheaf but a sheaf in what? sets, abelian groups, $O_Y$-modules? How do you define $f^\ast$ as opposed to $f^{-1}?
Sep
2
awarded  Custodian
Sep
2
reviewed Reviewed Dimension of Inverse image
Sep
2
comment Dimension of Inverse image
Welcome to MO, Ishita. The answer to your question is no: take $M=\mathbb R^2$, $N=\mathbb R$, $f(x,y)=x^2+y^2$. Then $0$ is a critical value, and $f^{-1}(0)=\{(0,0)\}$ is a smooth manifold of dimension 0. That being said, math.stackexchange is a better forum for this type of question. MO is for research-level question, while yours is a question at the level of a first course in differential geometry, something like (in the US system) an advanced undergrad or first-year grad course.
Aug
29
revised Elliptic curves with trace of Frobenius values always congruent to 0 modulo 2
deleted 27 characters in body
Aug
29
comment Elliptic curves with trace of Frobenius values always congruent to 0 modulo 2
Yes, of course. I edit.
Aug
29
answered Elliptic curves with trace of Frobenius values always congruent to 0 modulo 2
Aug
26
comment Finding integer points on elliptic curves via divisibility conditions like $(a+b)^2 \mid (2b^3+6ab^2-1)$
0.350... You're getting close! But you should consider writing explicitly in your answer, near the numerical examples, that an example with $m/l < 0.333$ would be a counter-example to the original OP's conjecture. Right now a new reader has to read carefully Lucia's answer or the comment on yours to find this information.
Aug
18
comment Kernel of the character of congruence groups
Dear Abdullah, I have slightly edited your question in order to introduce the precisions you gave in comments.