In this paper we determine the $\mathbb Q$-gonalities of the modular curves $X_0(N)$ for all $N<145$. We determine the $\mathbb C$-gonality of many of these curves and the $\mathbb Q$-gonalities …
In this paper we determine the $\mathbb Q$-gonalities of the modular curves $X_0(N)$ for all $N<145$. We determine the $\mathbb C$-gonality of many of these curves and the $\mathbb Q$-gonalities and $\mathbb C$-gonalities for many larger values of $N$. Using these results and some further work, we determine all the modular curves $X_0(N)$ of gonality $4$, $5$ and $6$ over $\mathbb Q$. We also find the first known instances of pentagonal curves $X_0(N)$ over $\mathbb C$.
We determine all modular curves $X_0(N)$ with infinitely many quartic points. To do this, we define a pairing that induces a quadratic form representing all possible degrees of a rational …
We determine all modular curves $X_0(N)$ with infinitely many quartic points. To do this, we define a pairing that induces a quadratic form representing all possible degrees of a rational morphism from $X_0(N)$ to a positive rank elliptic curve.
In this paper we determine all quotient curves $X_0^+(N)$ whose $\mathbb{Q}$ or $\mathbb{C}$-gonality is equal to $4$. As a consequence, we find several new cases when the modular curve $X_0(N)$ …
In this paper we determine all quotient curves $X_0^+(N)$ whose $\mathbb{Q}$ or $\mathbb{C}$-gonality is equal to $4$. As a consequence, we find several new cases when the modular curve $X_0(N)$ has $\mathbb{Q}$-gonality equal to $8$.
Let $N$ be a positive integer. For every $d | N$ such that $(d, N/d) = 1$ there exists an Atkin-Lehner involution $w_d$ of a modular curve $X_0(N)$. In this …
Let $N$ be a positive integer. For every $d | N$ such that $(d, N/d) = 1$ there exists an Atkin-Lehner involution $w_d$ of a modular curve $X_0(N)$. In this paper we determine all quotient curves $X_0(N)/w_d$ whose $\mathbb{Q}$-gonality is equal to $4$ and all quotient curves $X_0(N)/w_d$ whose $\mathbb{C}$-gonality is equal to $4$.
For every group $\{\pm1\}\subseteq \Delta\subseteq (\mathbb{Z}/N\mathbb{Z})^\times$, there exists an intermediate modular curve $X_\Delta(N)$. In this paper we determine all curves $X_\Delta(N)$ whose $\mathbb{Q}$-gonality is equal to $4$, all curves $X_\Delta(N)$ …
For every group $\{\pm1\}\subseteq \Delta\subseteq (\mathbb{Z}/N\mathbb{Z})^\times$, there exists an intermediate modular curve $X_\Delta(N)$. In this paper we determine all curves $X_\Delta(N)$ whose $\mathbb{Q}$-gonality is equal to $4$, all curves $X_\Delta(N)$ whose $\mathbb{C}$-gonality is equal to $4$, and all curves $X_\Delta(N)$ whose $\mathbb{Q}$-gonality is equal to $5$. We also determine the $\mathbb{Q}$-gonality of all curves $X_\Delta(N)$ for $N\leq 40$ and $\{\pm1\}\subsetneq \Delta \subsetneq (\mathbb{Z}/N\mathbb{Z})^\times$.
For every group $\{\pm1\}\subseteq \Delta\subseteq (\mathbb{Z}/N\mathbb{Z})^\times$, there exists an intermediate modular curve $X_\Delta(N)$. In this paper we determine all curves $X_\Delta(N)$ whose $\mathbb{Q}$-gonality is equal to $4$, all curves $X_\Delta(N)$ …
For every group $\{\pm1\}\subseteq \Delta\subseteq (\mathbb{Z}/N\mathbb{Z})^\times$, there exists an intermediate modular curve $X_\Delta(N)$. In this paper we determine all curves $X_\Delta(N)$ whose $\mathbb{Q}$-gonality is equal to $4$, all curves $X_\Delta(N)$ whose $\mathbb{C}$-gonality is equal to $4$, and all curves $X_\Delta(N)$ whose $\mathbb{Q}$-gonality is equal to $5$. We also determine the $\mathbb{Q}$-gonality of all curves $X_\Delta(N)$ for $N\leq 40$ and $\{\pm1\}\subsetneq \Delta \subsetneq (\mathbb{Z}/N\mathbb{Z})^\times$.
Let $N$ be a positive integer. For every $d | N$ such that $(d, N/d) = 1$ there exists an Atkin-Lehner involution $w_d$ of a modular curve $X_0(N)$. In this …
Let $N$ be a positive integer. For every $d | N$ such that $(d, N/d) = 1$ there exists an Atkin-Lehner involution $w_d$ of a modular curve $X_0(N)$. In this paper we determine all quotient curves $X_0(N)/w_d$ whose $\mathbb{Q}$-gonality is equal to $4$ and all quotient curves $X_0(N)/w_d$ whose $\mathbb{C}$-gonality is equal to $4$.
We determine all modular curves $X_0(N)$ with infinitely many quartic points. To do this, we define a pairing that induces a quadratic form representing all possible degrees of a rational …
We determine all modular curves $X_0(N)$ with infinitely many quartic points. To do this, we define a pairing that induces a quadratic form representing all possible degrees of a rational morphism from $X_0(N)$ to a positive rank elliptic curve.
In this paper we determine all quotient curves $X_0^+(N)$ whose $\mathbb{Q}$ or $\mathbb{C}$-gonality is equal to $4$. As a consequence, we find several new cases when the modular curve $X_0(N)$ …
In this paper we determine all quotient curves $X_0^+(N)$ whose $\mathbb{Q}$ or $\mathbb{C}$-gonality is equal to $4$. As a consequence, we find several new cases when the modular curve $X_0(N)$ has $\mathbb{Q}$-gonality equal to $8$.
In this paper we determine the $\mathbb Q$-gonalities of the modular curves $X_0(N)$ for all $N<145$. We determine the $\mathbb C$-gonality of many of these curves and the $\mathbb Q$-gonalities …
In this paper we determine the $\mathbb Q$-gonalities of the modular curves $X_0(N)$ for all $N<145$. We determine the $\mathbb C$-gonality of many of these curves and the $\mathbb Q$-gonalities and $\mathbb C$-gonalities for many larger values of $N$. Using these results and some further work, we determine all the modular curves $X_0(N)$ of gonality $4$, $5$ and $6$ over $\mathbb Q$. We also find the first known instances of pentagonal curves $X_0(N)$ over $\mathbb C$.
Let $\Phi^\infty(d)$ denote the set of finite abelian groups that occur infinitely often as the torsion subgroup of an elliptic curve over a number field of degree $d$. The sets …
Let $\Phi^\infty(d)$ denote the set of finite abelian groups that occur infinitely often as the torsion subgroup of an elliptic curve over a number field of degree $d$. The sets $\Phi^\infty(d)$ are known for $d\le 4$. In this article we determine $\Phi^\infty(5)$ and $\Phi^\infty(6)$.
Let $N$ be a positive integer, and let $\Gamma_{0}(N)=\{\left(\begin{array}{ll}a & b\\c & d\end{array}\right)\in SL_{2}(Z)|c\equiv 0(mod N)\}$ .Let $X_{0}(N)$ be the modular curve which corresponds to $\Gamma_{0}(N)$ .For each positive divisor …
Let $N$ be a positive integer, and let $\Gamma_{0}(N)=\{\left(\begin{array}{ll}a & b\\c & d\end{array}\right)\in SL_{2}(Z)|c\equiv 0(mod N)\}$ .Let $X_{0}(N)$ be the modular curve which corresponds to $\Gamma_{0}(N)$ .For each positive divisor $N^{\prime}$ of $N$ with $(N^{\prime}, N/N^{\prime})=1$ (in which case we write $N^{\prime}\Vert N$ ), $W_{N^{\prime}}=W_{N'}^{\langle N)}$ denotes the corresponding Atkin-Lehner involution on $X_{O}(N)$ . ($W_{1}$ is the identity.)It is known that the $W_{N^{\prime}}$ generate an elementary 2-abelian group, which we denote by $W(N)$ .The group $W(N)$ is of order $2^{\omega\langle N)}$ , where $\omega(N)$ is the number of distinct prime divisors of $N$ .Furthermore, these involutions are all defined over $Q:W(N)\subseteq Aut_{\Phi}(X_{0}(N))$ .Let $W^{\prime}$ be a subgroup of $W(N)$ .Then the hyperellipticity of the quotient curve $X_{0}(N)/W^{\prime}$ has been determined for two extreme cases (i.e., for $W^{\prime}=\{1\}$ or $W(N)$).THEOREM 1 ([12]).There are nineteen values ofNfor which $X_{0}(N)$ is hyperelliptic, $i.e.,$ $X_{0}(N)$ is hyperelliptic if and only if $N=22, 23,26,28-31,33,35,37,39-41,46-48,50,59,71$ .THEOREM 2 ([8] [6]).Put $X_{0}^{*}(N)=X_{0}(N)/W(N)$.There are 64 values ofNfor which $X_{0}^{*}(N)$ is hyperelliptic.(i) $X_{0}^{*}(N)$ is ofgenus two ifand only $ifN$ is in thefollowing list(57 values in total): 67, 73
Table of contents 0. Introduction 1. Algebraic preliminaries a.The Koszul cohomology groups b.Syzygies c. Cohomology operations d.The spectral sequence relating Koszul cohomology groups of an exact complex 2. The Duality …
Table of contents 0. Introduction 1. Algebraic preliminaries a.The Koszul cohomology groups b.Syzygies c. Cohomology operations d.The spectral sequence relating Koszul cohomology groups of an exact complex 2. The Duality Theorem a. Transition to the setting of complex manifolds b.The Gaussian class c.The Duality Theorem 3. Computational techniques for Koszul cohomology a.A vanishing theorem b.The "Lefschetz Theorem" c.The K pΛ Theorem 4. Applications a.The Theorem of the Top Row b.The Arbarello-Sernesi module and Petri's analysis of the ideal of a special curve .... c.The canonical ring of a variety of general type d.The H ] Lemma, a theorem of Kϋ, and a splitting lemma e.The H° Lemma f.A holomorphic representation of the H p ' q groups of a smooth variety 5. Open problems and conjectures A. Appendix (with Robert Lazarsfeld): The nonvanishing of certain Koszul cohomology groups
We determine which groups Z/MZ⊕Z/NZ occur infinitely often as torsion groups E(K)tors when K varies over all quartic number fields and E varies over all elliptic curves over K.
We determine which groups Z/MZ⊕Z/NZ occur infinitely often as torsion groups E(K)tors when K varies over all quartic number fields and E varies over all elliptic curves over K.
Tetragonal modular curves by Daeyeol Jeon and Euisung Park (Seoul) 0. Introduction.A smooth projective curve X defined over an algebraically closed field k is called d-gonal if it admits a …
Tetragonal modular curves by Daeyeol Jeon and Euisung Park (Seoul) 0. Introduction.A smooth projective curve X defined over an algebraically closed field k is called d-gonal if it admits a map φ : X → P 1 over k of degree d.If the genus g ≥ 2 and d = 2 then X is called hyperelliptic.We will say that X is trigonal, tetragonal and pentagonal for d = 3, d = 4 and d = 5 respectively.Let N be a positive integer, and letLet X 0 (N ) denote the modular curve corresponding to Γ 0 (N ).Then Zograf [Z] gave a linear bound on the level N of d-gonal modular curves X 0 (N ).Also Nguyen and Saito [N-Sa] proved an analogue of the strong Uniform Boundedness Conjecture for elliptic curves defined over function fields of dimension one by using the connection with giving a bound on the level N of d-gonal modular curves X 0 (N ).Recently, Hasegawa and Shimura [H-S] gave a highly sharpened upper bound for 3 ≤ d ≤ 5 by trying to determine d-gonal modular curves X 0 (N ) for such d.For d = 2 it was done by Ogg [O].Actually Hasegawa and Shimura succeeded in determining all trigonal modular curves X 0 (N ) but failed for tetragonal and pentagonal X 0 (N ).The following lists N for which they did not know whether X 0 (N ) was tetragonal or not: 76, 82, 84, 88, 90, 93, 97
For a positive integer $N$, let $X_0^*(N)$ denote the quotient curve of $X_0(N)$ by the Atkin-Lehmer involutions. In this paper, we determine the trigonality of $X_0^*(N)$ for all $N$. It …
For a positive integer $N$, let $X_0^*(N)$ denote the quotient curve of $X_0(N)$ by the Atkin-Lehmer involutions. In this paper, we determine the trigonality of $X_0^*(N)$ for all $N$. It turns out that there are seven values of $N$ for which $X_0^*(N)$ is a non-trivial trigonal curve.
Bruin and Najman [LMS J. Comput. Math. 18 (2015), no. 1, 578–602] and Ozman and Siksek [Math. Comp. 88 (2019), no. 319, 2461–2484] have recently determined the quadratic points on …
Bruin and Najman [LMS J. Comput. Math. 18 (2015), no. 1, 578–602] and Ozman and Siksek [Math. Comp. 88 (2019), no. 319, 2461–2484] have recently determined the quadratic points on each modular curve <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper X 0 left-parenthesis upper N right-parenthesis"> <mml:semantics> <mml:mrow> <mml:msub> <mml:mi>X</mml:mi> <mml:mn>0</mml:mn> </mml:msub> <mml:mo stretchy="false">(</mml:mo> <mml:mi>N</mml:mi> <mml:mo stretchy="false">)</mml:mo> </mml:mrow> <mml:annotation encoding="application/x-tex">X_0(N)</mml:annotation> </mml:semantics> </mml:math> </inline-formula> of genus 2, 3, 4, or 5 whose Mordell–Weil group has rank 0. In this paper we do the same for the <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper X 0 left-parenthesis upper N right-parenthesis"> <mml:semantics> <mml:mrow> <mml:msub> <mml:mi>X</mml:mi> <mml:mn>0</mml:mn> </mml:msub> <mml:mo stretchy="false">(</mml:mo> <mml:mi>N</mml:mi> <mml:mo stretchy="false">)</mml:mo> </mml:mrow> <mml:annotation encoding="application/x-tex">X_0(N)</mml:annotation> </mml:semantics> </mml:math> </inline-formula> of genus 2, 3, 4, and 5 and positive Mordell–Weil rank. The values of <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper N"> <mml:semantics> <mml:mi>N</mml:mi> <mml:annotation encoding="application/x-tex">N</mml:annotation> </mml:semantics> </mml:math> </inline-formula> are 37, 43, 53, 61, 57, 65, 67, and 73. The main tool used is a relative symmetric Chabauty method, in combination with the Mordell–Weil sieve. Often the quadratic points are not finite, as the degree 2 map <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper X 0 left-parenthesis upper N right-parenthesis right-arrow upper X 0 left-parenthesis upper N right-parenthesis Superscript plus"> <mml:semantics> <mml:mrow> <mml:msub> <mml:mi>X</mml:mi> <mml:mn>0</mml:mn> </mml:msub> <mml:mo stretchy="false">(</mml:mo> <mml:mi>N</mml:mi> <mml:mo stretchy="false">)</mml:mo> <mml:mo stretchy="false">→<!-- → --></mml:mo> <mml:msub> <mml:mi>X</mml:mi> <mml:mn>0</mml:mn> </mml:msub> <mml:mo stretchy="false">(</mml:mo> <mml:mi>N</mml:mi> <mml:msup> <mml:mo stretchy="false">)</mml:mo> <mml:mo>+</mml:mo> </mml:msup> </mml:mrow> <mml:annotation encoding="application/x-tex">X_0(N)\to X_0(N)^+</mml:annotation> </mml:semantics> </mml:math> </inline-formula> can be a source of infinitely many such points. In such cases, we describe this map and the rational points on <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper X 0 left-parenthesis upper N right-parenthesis Superscript plus"> <mml:semantics> <mml:mrow> <mml:msub> <mml:mi>X</mml:mi> <mml:mn>0</mml:mn> </mml:msub> <mml:mo stretchy="false">(</mml:mo> <mml:mi>N</mml:mi> <mml:msup> <mml:mo stretchy="false">)</mml:mo> <mml:mo>+</mml:mo> </mml:msup> </mml:mrow> <mml:annotation encoding="application/x-tex">X_0(N)^+</mml:annotation> </mml:semantics> </mml:math> </inline-formula>, and we specify the exceptional quadratic points on <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper X 0 left-parenthesis upper N right-parenthesis"> <mml:semantics> <mml:mrow> <mml:msub> <mml:mi>X</mml:mi> <mml:mn>0</mml:mn> </mml:msub> <mml:mo stretchy="false">(</mml:mo> <mml:mi>N</mml:mi> <mml:mo stretchy="false">)</mml:mo> </mml:mrow> <mml:annotation encoding="application/x-tex">X_0(N)</mml:annotation> </mml:semantics> </mml:math> </inline-formula> not coming from <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper X 0 left-parenthesis upper N right-parenthesis Superscript plus"> <mml:semantics> <mml:mrow> <mml:msub> <mml:mi>X</mml:mi> <mml:mn>0</mml:mn> </mml:msub> <mml:mo stretchy="false">(</mml:mo> <mml:mi>N</mml:mi> <mml:msup> <mml:mo stretchy="false">)</mml:mo> <mml:mo>+</mml:mo> </mml:msup> </mml:mrow> <mml:annotation encoding="application/x-tex">X_0(N)^+</mml:annotation> </mml:semantics> </mml:math> </inline-formula>. In particular, we determine the <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="j"> <mml:semantics> <mml:mi>j</mml:mi> <mml:annotation encoding="application/x-tex">j</mml:annotation> </mml:semantics> </mml:math> </inline-formula>-invariants of the corresponding elliptic curves and whether they are <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="double-struck upper Q"> <mml:semantics> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mi mathvariant="double-struck">Q</mml:mi> </mml:mrow> </mml:mrow> <mml:annotation encoding="application/x-tex">{\mathbb {Q}}</mml:annotation> </mml:semantics> </mml:math> </inline-formula>-curves or have complex multiplication.
Let $K$ be a number field, and let $E/K$ be an elliptic curve over $K$. The Mordell--Weil theorem asserts that the $K$-rational points $E(K)$ of $E$ form a finitely generated …
Let $K$ be a number field, and let $E/K$ be an elliptic curve over $K$. The Mordell--Weil theorem asserts that the $K$-rational points $E(K)$ of $E$ form a finitely generated abelian group. In this work, we complete the classification of the finite groups which appear as the torsion subgroup of $E(K)$ for $K$ a cubic number field. To do so, we determine the cubic points on the modular curves $X_1(N)$ for \[N = 21, 22, 24, 25, 26, 28, 30, 32, 33, 35, 36, 39, 45, 65, 121.\] As part of our analysis, we determine the complete list of $N$ for which $J_0(N)$ (resp., $J_1(N)$, resp., $J_1(2,2N)$) has rank 0. We also provide evidence to a generalized version of a conjecture of Conrad, Edixhoven, and Stein by proving that the torsion on $J_1(N)(\mathbb{Q})$ is generated by $\text{Gal}(\bar{\mathbb{Q}}/\mathbb{Q})$-orbits of cusps of $X_1(N)_{\bar{\mathbb{Q}}}$ for $N\leq 55$, $N \neq 54$.
Abstract We discuss the $\ell $ -adic case of Mazur’s ‘Program B’ over $\mathbb {Q}$ : the problem of classifying the possible images of $\ell $ -adic Galois representations attached …
Abstract We discuss the $\ell $ -adic case of Mazur’s ‘Program B’ over $\mathbb {Q}$ : the problem of classifying the possible images of $\ell $ -adic Galois representations attached to elliptic curves E over $\mathbb {Q}$ , equivalently, classifying the rational points on the corresponding modular curves. The primes $\ell =2$ and $\ell \ge 13$ are addressed by prior work, so we focus on the remaining primes $\ell = 3, 5, 7, 11$ . For each of these $\ell $ , we compute the directed graph of arithmetically maximal $\ell $ -power level modular curves $X_H$ , compute explicit equations for all but three of them and classify the rational points on all of them except $X_{\mathrm {ns}}^{+}(N)$ , for $N = 27, 25, 49, 121$ and two-level $49$ curves of genus $9$ whose Jacobians have analytic rank $9$ . Aside from the $\ell $ -adic images that are known to arise for infinitely many ${\overline {\mathbb {Q}}}$ -isomorphism classes of elliptic curves $E/\mathbb {Q}$ , we find only 22 exceptional images that arise for any prime $\ell $ and any $E/\mathbb {Q}$ without complex multiplication; these exceptional images are realised by 20 non-CM rational j -invariants. We conjecture that this list of 22 exceptional images is complete and show that any counterexamples must arise from unexpected rational points on $X_{\mathrm {ns}}^+(\ell )$ with $\ell \ge 19$ , or one of the six modular curves noted above. This yields a very efficient algorithm to compute the $\ell $ -adic images of Galois for any elliptic curve over $\mathbb {Q}$ . In an appendix with John Voight, we generalise Ribet’s observation that simple abelian varieties attached to newforms on $\Gamma _1(N)$ are of $\operatorname {GL}_2$ -type; this extends Kolyvagin’s theorem that analytic rank zero implies algebraic rank zero to isogeny factors of the Jacobian of $X_H$ .
We determine all trielliptic modular curves $X_1(N)$ over $\mathbb Q$, and construct explicit trielliptic maps from trielliptic $X_1(N)$ to elliptic curves. By using the trielliptic map constructed for $X_1(21)$, we …
We determine all trielliptic modular curves $X_1(N)$ over $\mathbb Q$, and construct explicit trielliptic maps from trielliptic $X_1(N)$ to elliptic curves. By using the trielliptic map constructed for $X_1(21)$, we find six non-cuspidal points of $X_1(21
We determine all modular curves $X_0^+(N)$ that admit infinitely many cubic points over the rational field $\mathbb {Q}$.
We determine all modular curves $X_0^+(N)$ that admit infinitely many cubic points over the rational field $\mathbb {Q}$.
Abstract A number field K is primitive if K and $$\mathbb {Q}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>Q</mml:mi> </mml:math> are the only subextensions of K . Let C be a curve defined over …
Abstract A number field K is primitive if K and $$\mathbb {Q}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>Q</mml:mi> </mml:math> are the only subextensions of K . Let C be a curve defined over $$\mathbb {Q}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>Q</mml:mi> </mml:math> . We call an algebraic point $$P\in C(\overline{\mathbb {Q}})$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>P</mml:mi> <mml:mo>∈</mml:mo> <mml:mi>C</mml:mi> <mml:mo>(</mml:mo> <mml:mover> <mml:mi>Q</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> <mml:mo>)</mml:mo> </mml:mrow> </mml:math> primitive if the number field $$\mathbb {Q}(P)$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>Q</mml:mi> <mml:mo>(</mml:mo> <mml:mi>P</mml:mi> <mml:mo>)</mml:mo> </mml:mrow> </mml:math> is primitive. We present several sets of sufficient conditions for a curve C to have finitely many primitive points of a given degree d . For example, let $$C/\mathbb {Q}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>C</mml:mi> <mml:mo>/</mml:mo> <mml:mi>Q</mml:mi> </mml:mrow> </mml:math> be a hyperelliptic curve of genus g , and let $$3 \le d \le g-1$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mn>3</mml:mn> <mml:mo>≤</mml:mo> <mml:mi>d</mml:mi> <mml:mo>≤</mml:mo> <mml:mi>g</mml:mi> <mml:mo>-</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> </mml:math> . Suppose that the Jacobian J of C is simple. We show that C has only finitely many primitive degree d points, and in particular it has only finitely many degree d points with Galois group $$S_d$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>S</mml:mi> <mml:mi>d</mml:mi> </mml:msub> </mml:math> or $$A_d$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>A</mml:mi> <mml:mi>d</mml:mi> </mml:msub> </mml:math> . However, for any even $$d \ge 4$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>d</mml:mi> <mml:mo>≥</mml:mo> <mml:mn>4</mml:mn> </mml:mrow> </mml:math> , a hyperelliptic curve $$C/\mathbb {Q}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>C</mml:mi> <mml:mo>/</mml:mo> <mml:mi>Q</mml:mi> </mml:mrow> </mml:math> has infinitely many imprimitive degree d points whose Galois group is a subgroup of $$S_2 \wr S_{d/2}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub> <mml:mi>S</mml:mi> <mml:mn>2</mml:mn> </mml:msub> <mml:mo>≀</mml:mo> <mml:msub> <mml:mi>S</mml:mi> <mml:mrow> <mml:mi>d</mml:mi> <mml:mo>/</mml:mo> <mml:mn>2</mml:mn> </mml:mrow> </mml:msub> </mml:mrow> </mml:math> .
Modular forms Modular forms of level $1$ Modular forms of weight $2$ Dirichlet characters Eisenstein series and Bernoulli numbers Dimension formulas Linear algebra General modular symbols Computing with newforms Computing …
Modular forms Modular forms of level $1$ Modular forms of weight $2$ Dirichlet characters Eisenstein series and Bernoulli numbers Dimension formulas Linear algebra General modular symbols Computing with newforms Computing periods Solutions to selected exercises Appendix A: Computing in higher rank Bibliography Index.
In this paper we prove the functoriality of the exterior square of cusp forms on <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper G upper L 4"> <mml:semantics> <mml:mrow> <mml:mi>G</mml:mi> <mml:msub> <mml:mi>L</mml:mi> <mml:mrow …
In this paper we prove the functoriality of the exterior square of cusp forms on <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper G upper L 4"> <mml:semantics> <mml:mrow> <mml:mi>G</mml:mi> <mml:msub> <mml:mi>L</mml:mi> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mn>4</mml:mn> </mml:mrow> </mml:msub> </mml:mrow> <mml:annotation encoding="application/x-tex">GL_{4}</mml:annotation> </mml:semantics> </mml:math> </inline-formula> as automorphic forms on <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper G upper L 6"> <mml:semantics> <mml:mrow> <mml:mi>G</mml:mi> <mml:msub> <mml:mi>L</mml:mi> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mn>6</mml:mn> </mml:mrow> </mml:msub> </mml:mrow> <mml:annotation encoding="application/x-tex">GL_{6}</mml:annotation> </mml:semantics> </mml:math> </inline-formula> and the symmetric fourth of cusp forms on <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper G upper L 2"> <mml:semantics> <mml:mrow> <mml:mi>G</mml:mi> <mml:msub> <mml:mi>L</mml:mi> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mn>2</mml:mn> </mml:mrow> </mml:msub> </mml:mrow> <mml:annotation encoding="application/x-tex">GL_{2}</mml:annotation> </mml:semantics> </mml:math> </inline-formula> as automorphic forms on <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper G upper L 5"> <mml:semantics> <mml:mrow> <mml:mi>G</mml:mi> <mml:msub> <mml:mi>L</mml:mi> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mn>5</mml:mn> </mml:mrow> </mml:msub> </mml:mrow> <mml:annotation encoding="application/x-tex">GL_{5}</mml:annotation> </mml:semantics> </mml:math> </inline-formula>. We prove these by applying a converse theorem of Cogdell and Piatetski-Shapiro to analytic properties of certain <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper L"> <mml:semantics> <mml:mi>L</mml:mi> <mml:annotation encoding="application/x-tex">L</mml:annotation> </mml:semantics> </mml:math> </inline-formula>-functions obtained by the Langlands-Shahidi method. We give several applications: First, we prove the weak Ramanujan property of cuspidal representations of <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper G upper L 4"> <mml:semantics> <mml:mrow> <mml:mi>G</mml:mi> <mml:msub> <mml:mi>L</mml:mi> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mn>4</mml:mn> </mml:mrow> </mml:msub> </mml:mrow> <mml:annotation encoding="application/x-tex">GL_{4}</mml:annotation> </mml:semantics> </mml:math> </inline-formula> and the absolute convergence of the exterior square <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper L"> <mml:semantics> <mml:mi>L</mml:mi> <mml:annotation encoding="application/x-tex">L</mml:annotation> </mml:semantics> </mml:math> </inline-formula>-functions of <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper G upper L 4"> <mml:semantics> <mml:mrow> <mml:mi>G</mml:mi> <mml:msub> <mml:mi>L</mml:mi> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mn>4</mml:mn> </mml:mrow> </mml:msub> </mml:mrow> <mml:annotation encoding="application/x-tex">GL_{4}</mml:annotation> </mml:semantics> </mml:math> </inline-formula>. Second, we prove that the fourth symmetric power <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper L"> <mml:semantics> <mml:mi>L</mml:mi> <mml:annotation encoding="application/x-tex">L</mml:annotation> </mml:semantics> </mml:math> </inline-formula>-functions of cuspidal representations of <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper G upper L 2"> <mml:semantics> <mml:mrow> <mml:mi>G</mml:mi> <mml:msub> <mml:mi>L</mml:mi> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mn>2</mml:mn> </mml:mrow> </mml:msub> </mml:mrow> <mml:annotation encoding="application/x-tex">GL_{2}</mml:annotation> </mml:semantics> </mml:math> </inline-formula> are entire, except for those of dihedral and tetrahedral type. Third, we prove the bound <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="three twenty-sixths"> <mml:semantics> <mml:mfrac> <mml:mn>3</mml:mn> <mml:mn>26</mml:mn> </mml:mfrac> <mml:annotation encoding="application/x-tex">\frac {3}{26}</mml:annotation> </mml:semantics> </mml:math> </inline-formula> for Hecke eigenvalues of Maass forms over any number field.
Let k be a quadratic field and E an elliptic curve defined over k . The authors [8, 12, 13] [23] discussed the k -rational points on E of prime …
Let k be a quadratic field and E an elliptic curve defined over k . The authors [8, 12, 13] [23] discussed the k -rational points on E of prime power order. For a prime number p , let n = n(k, p ) be the least non negative integer such that for all elliptic curves E defined over a quadratic field k ([15]).
We show that the twofold symmetric product of a nonhyperelliptic, nonbielliptic curve does not contain any elliptic curves. Applying a theorem of Faltings, we conclude that such a curve defined …
We show that the twofold symmetric product of a nonhyperelliptic, nonbielliptic curve does not contain any elliptic curves. Applying a theorem of Faltings, we conclude that such a curve defined over a number field <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper K"> <mml:semantics> <mml:mi>K</mml:mi> <mml:annotation encoding="application/x-tex">K</mml:annotation> </mml:semantics> </mml:math> </inline-formula> has only finitely many points over all quadratic extensions of <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper K"> <mml:semantics> <mml:mi>K</mml:mi> <mml:annotation encoding="application/x-tex">K</mml:annotation> </mml:semantics> </mml:math> </inline-formula>. We illustrate our theory with the modular curves <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper X 0 left-parenthesis upper N right-parenthesis comma upper X 1 left-parenthesis upper N right-parenthesis comma upper X left-parenthesis upper N right-parenthesis"> <mml:semantics> <mml:mrow> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:msub> <mml:mi>X</mml:mi> <mml:mn>0</mml:mn> </mml:msub> </mml:mrow> <mml:mo stretchy="false">(</mml:mo> <mml:mi>N</mml:mi> <mml:mo stretchy="false">)</mml:mo> <mml:mo>,</mml:mo> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:msub> <mml:mi>X</mml:mi> <mml:mn>1</mml:mn> </mml:msub> </mml:mrow> <mml:mo stretchy="false">(</mml:mo> <mml:mi>N</mml:mi> <mml:mo stretchy="false">)</mml:mo> <mml:mo>,</mml:mo> <mml:mi>X</mml:mi> <mml:mo stretchy="false">(</mml:mo> <mml:mi>N</mml:mi> <mml:mo stretchy="false">)</mml:mo> </mml:mrow> <mml:annotation encoding="application/x-tex">{X_0}(N),{X_1}(N),X(N)</mml:annotation> </mml:semantics> </mml:math> </inline-formula>.
Let N be an integer ≥ 1. The affine modular curve Y 0 ( N ) parameterizes isomorphism classes of pairs ( E; F ), where E is an elliptic …
Let N be an integer ≥ 1. The affine modular curve Y 0 ( N ) parameterizes isomorphism classes of pairs ( E; F ), where E is an elliptic curve defined over ℂ, the field of complex numbers, and F is a cyclic subgroup of order N. The compacti-fication X 0 ( N ) is an algebraic curve defined over ℚ.
Let $W(N)$ be the group of Atkin-Lehner involutions on the modular curve $X_0(N)$. The purpose of this article is to give complementary result to [7, 8, 9]; namely, we determine …
Let $W(N)$ be the group of Atkin-Lehner involutions on the modular curve $X_0(N)$. The purpose of this article is to give complementary result to [7, 8, 9]; namely, we determine trigonal curves of the form $X_0(N)/W'$, where $W'$ is a subgroup of $W(N)$ such that $2< |W'| < |W(N)|$.
Recently (3) Mazur proved that if N is a prime number such that some elliptic curve E over Q admits a Q-rational isogeny then N is one of 2, 3, …
Recently (3) Mazur proved that if N is a prime number such that some elliptic curve E over Q admits a Q-rational isogeny then N is one of 2, 3, 5, 7, 11, 13, 17, 19, 37, 43, 67 or 163.