About Sturm's bound












1












$begingroup$


The next theorem is known as Sturm's bound.



Theorem:Let $mathfrak{m}$ be a prime ideal in the ring of integers $mathcal{O}$ of a number field $K$, and let $Gamma$ be a congruence subgroup of of index $m$ and level $N$. Suppose $fin M_k(Gamma,mathcal{O})$ is a modular form and
begin{align}
mathrm{ord}_{mathfrak{m}}(f)>dfrac{km}{2}.
end{align}

Then $fequiv 0;(mathrm{mod},mathfrak{m})$.



I want to know if all the sophisticated techniques that Sturm uses in his proof are necessary? In other words, is there a elementary proof? I found, in the case of $mathrm{SL}_2(mathbb{Z})$, a sketch of a proof in a book (Problems In The Theory of modular forms by M. Ram Murty ) but i can't realize a complete proof.
Especifically, I'm struggling with the width of cusps, why the existence of a represent of a coset associated to a cusp with $h$ as the value of the width implies the existence of other $h-1$ representatives with the same value of width.










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$endgroup$

















    1












    $begingroup$


    The next theorem is known as Sturm's bound.



    Theorem:Let $mathfrak{m}$ be a prime ideal in the ring of integers $mathcal{O}$ of a number field $K$, and let $Gamma$ be a congruence subgroup of of index $m$ and level $N$. Suppose $fin M_k(Gamma,mathcal{O})$ is a modular form and
    begin{align}
    mathrm{ord}_{mathfrak{m}}(f)>dfrac{km}{2}.
    end{align}

    Then $fequiv 0;(mathrm{mod},mathfrak{m})$.



    I want to know if all the sophisticated techniques that Sturm uses in his proof are necessary? In other words, is there a elementary proof? I found, in the case of $mathrm{SL}_2(mathbb{Z})$, a sketch of a proof in a book (Problems In The Theory of modular forms by M. Ram Murty ) but i can't realize a complete proof.
    Especifically, I'm struggling with the width of cusps, why the existence of a represent of a coset associated to a cusp with $h$ as the value of the width implies the existence of other $h-1$ representatives with the same value of width.










    share|cite|improve this question











    $endgroup$















      1












      1








      1





      $begingroup$


      The next theorem is known as Sturm's bound.



      Theorem:Let $mathfrak{m}$ be a prime ideal in the ring of integers $mathcal{O}$ of a number field $K$, and let $Gamma$ be a congruence subgroup of of index $m$ and level $N$. Suppose $fin M_k(Gamma,mathcal{O})$ is a modular form and
      begin{align}
      mathrm{ord}_{mathfrak{m}}(f)>dfrac{km}{2}.
      end{align}

      Then $fequiv 0;(mathrm{mod},mathfrak{m})$.



      I want to know if all the sophisticated techniques that Sturm uses in his proof are necessary? In other words, is there a elementary proof? I found, in the case of $mathrm{SL}_2(mathbb{Z})$, a sketch of a proof in a book (Problems In The Theory of modular forms by M. Ram Murty ) but i can't realize a complete proof.
      Especifically, I'm struggling with the width of cusps, why the existence of a represent of a coset associated to a cusp with $h$ as the value of the width implies the existence of other $h-1$ representatives with the same value of width.










      share|cite|improve this question











      $endgroup$




      The next theorem is known as Sturm's bound.



      Theorem:Let $mathfrak{m}$ be a prime ideal in the ring of integers $mathcal{O}$ of a number field $K$, and let $Gamma$ be a congruence subgroup of of index $m$ and level $N$. Suppose $fin M_k(Gamma,mathcal{O})$ is a modular form and
      begin{align}
      mathrm{ord}_{mathfrak{m}}(f)>dfrac{km}{2}.
      end{align}

      Then $fequiv 0;(mathrm{mod},mathfrak{m})$.



      I want to know if all the sophisticated techniques that Sturm uses in his proof are necessary? In other words, is there a elementary proof? I found, in the case of $mathrm{SL}_2(mathbb{Z})$, a sketch of a proof in a book (Problems In The Theory of modular forms by M. Ram Murty ) but i can't realize a complete proof.
      Especifically, I'm struggling with the width of cusps, why the existence of a represent of a coset associated to a cusp with $h$ as the value of the width implies the existence of other $h-1$ representatives with the same value of width.







      algebraic-number-theory modular-forms elliptic-functions






      share|cite|improve this question















      share|cite|improve this question













      share|cite|improve this question




      share|cite|improve this question








      edited Dec 18 '18 at 13:23







      A. Gomez

















      asked Dec 18 '18 at 6:50









      A. GomezA. Gomez

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      256






















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