diff --git a/main.tex b/main.tex index 47f1de3ffede417784dfa53a4909c07e7c692742..c0169c4bbaff9fa9806951e8e91e0cc55c6b94d7 100644 --- a/main.tex +++ b/main.tex @@ -521,6 +521,7 @@ bound for the rank of $E$: \end{proof} \begin{example}[$v=(3, 2\ell, -2)$ on $\PP^2$] +\label{exmpl:recurring-first} \begin{sagesilent} recurring = Object() recurring.chern = Chern_Char(3, 2, -2) @@ -1421,7 +1422,7 @@ r_upper_bound_all_q = ( \end{sagesilent} \begin{corrolary}[Bound on $r$ \#2] - \label{cor:direct_rmax_with_uniform_eps} +\label{cor:direct_rmax_with_uniform_eps} Let $v$ be a fixed Chern character and $R:=\chern_0(v) \leq \frac{1}{2}\lcm(m,2n^2)\Delta(v)$. Then the ranks of the pseudo-semistabilizers for $v$ @@ -1468,6 +1469,28 @@ stated in the corollary. \egroup \end{proof} +\begin{example}[$v=(3, 2\ell, -2)$ on $\PP^2$] +Just like in example \ref{exmpl:recurring-first}, take +$\ell=c_1(\mathcal{O}(1))$ as the standard polarization on $\PP^2$, so +that $m=2$, $\beta_-=\sage{recurring.b}$, +giving $n=\sage{recurring.b.denominator()}$. + +\begin{sagesilent} +n = recurring.b.denominator() +m = 2 +recurring.bgmlv = recurring.chern.Q_tilt() +recurring.lcm = lcm(m, 2*n^2) +corrolary_bound = ( + recurring.bgmlv * recurring.lcm / 8 + + recurring.chern.ch[0] / 2 + + recurring.chern.ch[0]^2 / (2*recurring.bgmlv*recurring.lcm) +) +\end{sagesilent} +Using the above corrolary \ref{cor:direct_rmax_with_uniform_eps}, we get that +the ranks of tilt semistabilizers for $v$ are bounded above by +$\sage{corrolary_bound} \approx \sage{float(corrolary_bound)}$, +which is much closer to real maximum 25 than the original bound 144. +\end{example} %% refinements using specific values of q and beta These bound can be refined a bit more by considering restrictions from the