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1 answer
153 views

On Mordell equation $y^2=x^3+k$ [closed]

Have the Mordell equation $y^2=x^3+k$ solved for all integer $k$ or not? Please Could you tell me about a good review papers about such equation.
1 vote
1 answer
93 views

A correspondence between pairs of isogenies and representation numbers

This question is re-posted from MSE because it didn't seem to get any traction/responses there. This is a question from this paper about a correspondence between representation numbers of quadratic ...
2 votes
1 answer
151 views

Flexes and projective equivalence of smooth cubics

I am trying to study Kock and Vainsencher's book "An invitation to Quantum Cohomology", working my way through the exercises. One of them ($0$th chapter) asks two prove that two elliptic ...
3 votes
0 answers
88 views

cubic twists of Mordell curve and their rank

Let $a$ be a non-zero integer. Consider the elliptic curve $E_a/\mathbb{Q}$ given by the equation $$ E_a: y^2 = x^3 + a. $$ For a cube-free integer $D$, define the elliptic curves $E_{aD^2}/\mathbb{Q}$...
6 votes
3 answers
4k views

Re: Mordell's equation $y^2 = x^3 + k$ and perfect numbers

I have already tried a somewhat exhaustive search of the literature, but couldn't find anything close to the problem that I am working on. My question is: When does Mordell's equation $$Y^2 = X^3 + K$$...
2 votes
1 answer
383 views

Simple isogeny question

I'm looking for a reference of an isogeny fact that I've used many times but am having a hard time proving formally. One can define the degree of an isogeny as the degree of extension fields of the ...
18 votes
2 answers
888 views

Serre’s comment on Hurwitz: connecting FLT to points of finite order on elliptic curves

In the paper Sur les représentations modulaire de degré 2 de Gal$(\overline{\mathbb{Q}}/\mathbb{Q})$, Serre makes the following comment: Remarque. La relation existant entre "solutions de l'...
5 votes
1 answer
340 views

Equations for dual cubic curves

Suppose I have a cubic curve $C$ (over $\mathbb C$) in Weierstrass form $$y^2=x^3+ax+b.$$ I would like to find the degree $6$ equation for protectively dual curve $C^*$. Do you know any place where ...
0 votes
0 answers
66 views

Parametrization of elliptic curve with differential equation $(x,y)=(f(x),f'(x))$ involving Lambert $W$ function

For non-zero complex $A$, define the curve over the complex numbers $C: x^2 y^2-A x-y=0$. $C$ is an elliptic curve. $C$ has the differential equation parametrization $(x,y)=(f(x),f'(x))$ where $$ f(x)=...
5 votes
0 answers
126 views

Using Lang–Trotter to get bounds on averages of Fourier coefficients

Let $E$ be an elliptic curve over $\mathbf{Q}$ and let $(a_n)$ be the sequence of Fourier coefficients for the weight two newform attached to $E$. The coefficients $a_p$ are the Frobenius traces given ...
10 votes
2 answers
286 views

Finding a model for $X_G$ with $G\subseteq \mathrm{GL}_2(\mathbb{Z}/N\mathbb{Z})$

I'm studying modular curves as part of my doctorate work and would like to understand how one gets from a subgroup $G$ of $\operatorname{GL}_2(\mathbb{Z}/N\mathbb{Z})$ to an equation for $X_G$. By $...
2 votes
1 answer
344 views

On Iwasawa theory of elliptic curves in $\mathrm{PGL}_2(\mathbb{Z}_p)$-extension

Let $E$ be an elliptic curve over the rationals $\mathbb{Q}$. We consider the Galois representation attached to $E$ by acting on its $p$-adic Tate module $T_p(E)$, $$ \rho_E: G_{K} \rightarrow \mathrm{...
3 votes
1 answer
366 views

Descent for étale covers of proper regular models of elliptic curves

Let $K$ be a complete (but think Henselian suffice for purposes of this question) local field of characteristic $0$ with residue field $k$ of characteristic $p>0$ and ring of integers $R=\mathcal{O}...
4 votes
0 answers
100 views

Structure of points of elliptic curves in field with restricted ramification

Let $k$ be a finite field of characteristic $p$ and let $C$ be a curve over $k$. Let $E$ be a non-constant elliptic curve over $k(C)$. Taking the Néron model of $E$ and removing the singular fibers ...
3 votes
0 answers
139 views

Do the denominators of A006571(n)/A366450(n) have a Dirichlet generating function? Because they partially match A071974(n) and A056622(n)?

Consider the expansion: $$A006571(n) = q \prod _{k=1}^{\infty } \left(1-q^k\right)^2 \left(1-q^{11 k}\right)^2 \label{1}\tag{1}$$ A006571 and the triple sum: $$A366450(n)=\sum _{k=1}^n \left(\sum _{y=...
7 votes
1 answer
233 views

Proven results for the refined Birch Swinnerton-Dyer conjecture over rationals when rank at most $1$

For an elliptic curve, $E$, defined over $\mathbb{Q}$ and with the Mordell-Weil group, $E(\mathbb{Q})$, having rank, $r$, the Birch Swinnerton-Dyer (BSD) conjecture states that $$ c_{E} = \lim_{s \...
2 votes
1 answer
204 views

What does the Serre functor of equivariant category of fractional CY category look like?

I am considering the following set up. Let $\mathcal{A}$ be a fractional Calabi-Yau category and denote by $S$ the Serre functor and $S^m=[n]$. Now I consider a finite group action $G$ on $\mathcal{A}$...
3 votes
3 answers
1k views

Rank and generators of elliptic curve

I need to calculate the rank and the generators of the elliptic curve [0,1,0,-15662264585,746984342506759] that is, $$ y^2 = x^3 + x^2 -15662264585 x ...
5 votes
0 answers
172 views

"Genus theory" for elliptic curve $L$-functions

Let $d$ be a positive integer, so that $-d$ is a fundamental discriminant. This means that $d$ is square-free at odd primes and $\nu_2(d) \in \{0, 2, 3\}$. Further, if $\nu_2(d) > 0$ then $-d 2^{-\...
1 vote
0 answers
85 views

Action of Atkin--Lehner involution on CM points

In their first paper on Heegner points and derivatives of $L$-series, Gross and Zagier describe the action of Atkin--Lehner involutions on certain CM $\mathbf{C}$-points of the modular curve $X_0(N)$. ...
2 votes
0 answers
96 views

On the root numbers of quadruples of quadratic twists of elliptic curves

We got strong numerical evidence for the root numbers and analytic ranks of quadruples of elliptic curves over the rationals. Related to this question. Let $k,k_1,k_2$ be squarefree pairwise coprime ...
0 votes
0 answers
108 views

looking for reference for two elliptic curves with equal formal group

I am looking for a reference. In this post, @Chris Wurthrich made the following comment: If the formal group laws (probably upon particular choice of coordinates) of two elliptic curves over any ring ...
3 votes
0 answers
241 views

Generating algebraic points on elliptic curves

Let $E$ be an elliptic curve over $\mathbf{Q}$. One has the modular parameterisation \begin{align*} \mathbf{H} \to X_0(N)(\mathbf{C}) \to E(\mathbf{C}) \end{align*} where $X_0(N)$ is the modular curve ...
2 votes
1 answer
195 views

Can we get a homomorphism between two elliptic curves if we know a homomorphism between the respective formal groups?

Let $E_1$ and $E_2$ be two elliptic curves over a field of characteristic $0$, and let $\hat{E_1}$ and $\hat{E_2}$ be two formal group laws associated with $E_1$ and $E_2$, respectively. It is known ...
7 votes
3 answers
349 views

The rank of elliptic curves and related quadratic twists

Let $E/\mathbb{Q}$ be an elliptic curve, and let $k_1, k_2$ be square-free integers. Can anything be said about the related elliptic curves $$\displaystyle E/\mathbb{Q}, E^{(k_1)}/\mathbb{Q}, E^{(k_2)}...
9 votes
3 answers
584 views

Do rational points on $X(1)$ correspond to elliptic curves up to rational isomorphism?

I'm not sure whether this is obvious or not. The curve $X(1)$ parametrices all elliptic curves up to isomorphism class over $\mathbb{ C}$, and a $K$-rational point corresponds to an elliptic curve ...
18 votes
2 answers
2k views

What is the taxicab number for rational fourth powers?

The taxicab number is the smallest integer that can be expressed as a sum of two positive integer cubes in two different ways, and it is equal to $1729=12^3+1^3=10^3+9^3$. There are generalizations to ...
3 votes
1 answer
103 views

special $g_3^1$ on elliptic curve

Let $C$ be a planar smooth cubic curve. We know that projection from a point $p$ that does not lie on $C$ produces a 3-to-1 map $\pi: C\to \mathbb P^1$, which has 6 ramification points in general. Now,...
7 votes
0 answers
170 views

Nondeterminism in Magma software while computing generators of an elliptic curve

Computing generators of a Mordell curve $$y^2 = x^3 - 44275089430000,$$ can be done in Magma by running the following code: ...
1 vote
1 answer
143 views

Algorithm for computing isogeny class of elliptic curve

Is there an algorithm for computing the entire isogeny class of a given elliptic curve $E/\mathbb{Q}$? References/ideas are welcome. Thanks!
17 votes
2 answers
2k views

How to think of algebraic geometry in characteristic p?

How does a working mathematician usually think about algebraic geometry in characteristic $p$? For the sake of concreteness, and to make things more "geometric" (whatever that means), let's ...
0 votes
0 answers
49 views

Is there a correlation between the bifurcation points of dynamical system and the integral points of the elliptic curve $E_d$?

Motivated by an interest in the interplay between dynamical systems and elliptic curves also On a question of Mordell, I derived a dynamical system corresponding to the elliptic curve: $ E_d: Y^2 = X^...
0 votes
0 answers
81 views

Computing elliptic periods from modular form

How are the periods of a modular elliptic curve computed as path integrals of its associated normalized weight 2 cusp form on the modular curve? Please provide specific paths for both periods and cite ...
8 votes
0 answers
208 views

Elliptic curves of rank 1 over number fields

I am interested what is known about the following statement: For every number field $K$, there exists an elliptic curve $E$ defined over $K$ with algebraic rank equal to $1$. Is this statement known ...
3 votes
0 answers
192 views

How can I prove this stronger version of Fedder's Criterion?

I was reading Fedder's original paper which proved what is now known as "Fedder's criterion". I noticed that the abstract stated something which is a priori stronger than what is proved in ...
0 votes
0 answers
100 views

Algebraic degrees of $j\left(\sqrt{-n}\right)$ and $j\left(\frac{1 + \sqrt{-n}}{2}\right)$ and class numbers of $Q(\sqrt{-n})$

Let $n\in\mathbb N$ be squarefree. Denote by $h(n)$ the class number of $Q(\sqrt{-n})$ and by $d_1(n)$ and $d_2(n)$ the degrees of the algebraic numbers $j\left(\sqrt{-n}\right)$ and $j\left(\frac{1 + ...
9 votes
3 answers
2k views

Characterisation for separable extension of a field

Can someone verify this for me.. or tell me what reference shows me this... is this true: Let $k$ be a field. Then a field extension $K$ of $k$ is separable over $k$ iff for any field extension $L \...
2 votes
0 answers
234 views

Elliptic curve with rank at least $6$

I was going through a research paper which proves the existence of an infinite family of rank $6$ elliptic curves over $\mathbb{Q}$ with invariant equal to $0$. Let $k$ be a field of characteristic ...
2 votes
1 answer
345 views

Why this genus one curve over $\mathbb{F}_5$ appear to violate Hasse-Weil bound?

Working over $\mathbb{F}_5$, the affine curve $x^4+2=y^2$ has no points. The projective curve $x^4+2y^4=z^2y^2$ has only one point $(0 : 0 : 1)$. Both curves appear to violate Hasse-Weil bound of $4....
3 votes
1 answer
222 views

Large integral points on the quadratic twist $ D y^2=x^3+A x +B$

For integers $A,B,D$ and $D$ squarefree let $E : y^2=x^3+A x + B$ and $E_D$ be the quadratic twist of the elliptic curve $E$: $$ E_D : D y^2=x^3+Ax +B$$ $E_D$ is isomorphic to $ E'_D : y^2=x^3+D^2 A ...
0 votes
0 answers
108 views

Isogeny classes for elliptic curves over quadratic field

Question. Is it possible for an elliptic curve $E$ over quadratic field $K$ to have two separate (yet connected) isogeny classes? There are two $\mathbb{Z}/14\mathbb{Z}$ elliptic curves, $E_1$ and $...
2 votes
0 answers
52 views

Infinitely many coprime solutions of $F(x,y)= k(a_1 x + a_2 y)^2 z^2$?

This might be related to an open problem. Let $F(x,y)$ be homogeneous degree 4 squarefree polynomial with integer coefficients and $h(x,y)=a_1 x + a_2 y$ and $\gcd(F,h)=1$ and $k$ be integer. Consider ...
1 vote
1 answer
235 views

Are there conditions for an elliptic curve to have a quadratic $\mathbb{F}_q$-cover of the line without ramification $\mathbb{F}_q$-points?

Consider an elliptic curve $E: y^2 = f(x) := x^3 + ax + b$ over a finite field $\mathbb{F}_q$ of characteristic $> 3$. Obviously, the projection to $x$ is a quadratic $\mathbb{F}_q$-cover of the ...
8 votes
1 answer
365 views

Evidence for the equivariant BSD conjecture with higher multiplicity

Let $E/\mathbb{Q}$ be an elliptic curve and let $\rho$ be an irreducible Artin representation. Let $K_\rho/\mathbb{Q}$ be the smallest Galois extension such that $\rho$ factors through $\mathrm{Gal}(...
2 votes
1 answer
163 views

Fixed $a_p=p+1-\#E(\mathbb{F}_p)$ and $a_p \ne 0$ on an elliptic curve infinitely often for fixed curve over the rationals?

In this and this question we show that if $p=27a^2+27a+7$ is prime, then the order of the elliptic curve $y^2=x^3+2$ modulo $p$ is either $p$ or $p+2$. Q1 Can we unconditionally show that the order ...
2 votes
0 answers
92 views

Tate curve and components of special fibre II

Let $K$ be complete local field of characteristic $0$ with ring of integers $R=\mathcal{O}_{K}$ and residue field $k=R/\mathfrak{m}_R$ of characteristic $p>0$. Let $E/K$ be an elliptic curve of ...
2 votes
0 answers
103 views

Existence of supersingular abelian variety over $\mathbb F_p$ with $\mathcal O_E$-action where $E/\mathbb Q$ is quadratic imaginary ramified at $p$

Let $E/\mathbb Q$ be a quadratic totally imaginary number field with ring of integers $\mathcal O_E$. Let $p > 2$ be an odd prime number which ramifies in $\mathcal O_E$. Let $\mathcal P$ be the ...
1 vote
0 answers
153 views

Tate curve and components of special fibre

Let $K$ be a complete local field of characteristic $0$ with ring of integers $R=\mathcal{O}_{K}$ and residue field $k=R/\mathfrak{m}_R$ of characteristic $p>0$. Let $E/K$ be an elliptic curve of ...
0 votes
0 answers
61 views

Is generating semirandom blake256 hashes until packed points is on the curve, a safe algorithm to avoid the discrete log between the generated points?

I know there are more robust methods, but I wanted to know about this specific one For any distinct said randomly generated point : $P_i,P_j\in \{P_1,...,P_k\}$ it should be hard to find $s$ such that ...
3 votes
1 answer
350 views

Elements of $\mathbb{F}_p$ represented by an irreducible polynomial $f(x) = x^3 +a_2 x^2 + a_1 x + a_0$, $f(x) \in \mathbb{F}_p[x]$

Let $p \equiv 1 \bmod 3$ be a prime, $\mathbb{F}_p$ be the finite field with $p$ elements, and $a_0$ be a generator of $\mathbb{F}_p^{\times}$ $(\mathbb{F}_p^{\times}$ the group of nonzero elements of ...

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