<p>Let <InlineEquation ID="IEq1"> <EquationSource Format="TEX">\(\varvec{J}\)</EquationSource> </InlineEquation> be the Jacobian of a superelliptic curve defined by the equation <InlineEquation ID="IEq2"> <EquationSource Format="TEX">\(\varvec{y}^{\varvec{\ell }} \varvec{= f(x)}\)</EquationSource> </InlineEquation>, where <InlineEquation ID="IEq3"> <EquationSource Format="TEX">\(\varvec{f}\)</EquationSource> </InlineEquation> is a separable polynomial of degree non-divisible by <InlineEquation ID="IEq4"> <EquationSource Format="TEX">\(\varvec{\ell }\)</EquationSource> </InlineEquation>. Recall that <InlineEquation ID="IEq5"> <EquationSource Format="TEX">\(\varvec{J}\)</EquationSource> </InlineEquation> is an abelian variety of dimension <InlineEquation ID="IEq6"> <EquationSource Format="TEX">\(\varvec{\frac{1}{2}(\ell - 1)(\text {deg} f-1)}\)</EquationSource> </InlineEquation>. In this article we study the exponential (i.e. <InlineEquation ID="IEq7"> <EquationSource Format="TEX">\(\varvec{\ell }\)</EquationSource> </InlineEquation>-power) torsion of <InlineEquation ID="IEq8"> <EquationSource Format="TEX">\(\varvec{J}\)</EquationSource> </InlineEquation>. In particular, under some mild conditions on the polynomial&#xa0;<InlineEquation ID="IEq9"> <EquationSource Format="TEX">\(\varvec{f}\)</EquationSource> </InlineEquation>, we determine the image of the associated <InlineEquation ID="IEq10"> <EquationSource Format="TEX">\(\varvec{\ell }\)</EquationSource> </InlineEquation>-adic representation up to the determinant. We show also that the image of the determinant is contained in an explicit <InlineEquation ID="IEq11"> <EquationSource Format="TEX">\({\varvec{\mathbb {Z}}}_{\varvec{\ell }}\)</EquationSource> </InlineEquation>-lattice with a finite index. As an application, we prove new cases of the Hodge, Tate and Mumford–Tate conjectures for generic superelliptic Jacobians of the above type.</p>

错误:搜索内容不能为空,请输入英文关键词
错误:关键词超出字数限制,请精简
高级检索

The Exponential Torsion of Superelliptic Jacobians

  • Jędrzej Garnek

摘要

Let \(\varvec{J}\) be the Jacobian of a superelliptic curve defined by the equation \(\varvec{y}^{\varvec{\ell }} \varvec{= f(x)}\) , where \(\varvec{f}\) is a separable polynomial of degree non-divisible by \(\varvec{\ell }\) . Recall that \(\varvec{J}\) is an abelian variety of dimension \(\varvec{\frac{1}{2}(\ell - 1)(\text {deg} f-1)}\) . In this article we study the exponential (i.e. \(\varvec{\ell }\) -power) torsion of \(\varvec{J}\) . In particular, under some mild conditions on the polynomial  \(\varvec{f}\) , we determine the image of the associated \(\varvec{\ell }\) -adic representation up to the determinant. We show also that the image of the determinant is contained in an explicit \({\varvec{\mathbb {Z}}}_{\varvec{\ell }}\) -lattice with a finite index. As an application, we prove new cases of the Hodge, Tate and Mumford–Tate conjectures for generic superelliptic Jacobians of the above type.