Newer
Older
\begin{equation*}
\sage{positive_radius_condition.subs([q_value_expr,beta_value_expr]).factor()}
\end{equation*}
\noindent
Then we have:
\begin{equation*}
d - \frac{(\aa r + 2\bb)\aa}{2n^2}
\geq \epsilon_{q,2} \geq \epsilon_{q,1} > 0
\end{equation*}
Where $\epsilon_{q,1}$ and $\epsilon_{q,2}$ are defined as follows:
\frac{k_q^2}{2mn^2}
\end{equation*}
\begin{align*}
\text{where }
&k_q^1 \text{ is the least }
k\in\ZZ_{>0}\: s.t.:\:
k \equiv -\aa\bb m \mod n
\\
&k_q^2 \text{ is the least }
k\in\ZZ_{>0}\: s.t.:\:
k \equiv \aa\bb m (\aa\aa^{'}-2)
\mod n\gcd(2n,\aa^2 m)
\end{align*}
\end{lemmadfn}
It is worth noting that $\epsilon_{q,2}$ is potentially larger than
$\epsilon_{q,2}$
but calculating it involves a $\gcd$, a modulo reduction, and a modulo $n$
inverse, for each $q$ considered.
\begin{proof}
Consider the following tautology:
- \frac{
(\aa r+2\bb)\aa
}{
2n^2
}
= \frac{ k }{ 2mn^2 }
\quad \text{for some } x \in \ZZ
\span \span \span \span \span
\label{eqn:finding_better_eps_problem}
&\equiv k &&
\mod 2n^2
\\ &\Longleftrightarrow&
- \aa^2 m r - 2\aa\bb m
&\equiv k &&
\mod 2n^2
\\ &\Longrightarrow&
\aa^2 \aa^{'}\bb m - 2\aa\bb m
&\equiv k &&
\mod \gcd(2n^2, \aa^2 mn)
\label{eqn:better_eps_problem_k_mod_gcd2n2_a2mn}
\label{eqn:better_eps_problem_k_mod_n}
In our situation, we want to find the least $k$ satisfying
eqn \ref{eqn:finding_better_eps_problem}.
Since such a $k$ must also satisfy eqn \ref{eqn:better_eps_problem_k_mod_n},
we can pick the smallest $k_q^1 \in \ZZ_{>0}$ which satisfies this new condition
(a computation only depending on $q$ and $\beta$, but not $r$).
We are then guaranteed that the gap $\frac{k}{2mn^2}$ is at least
$\epsilon_{q,1}$.
Furthermore, $k$ also satisfies
eqn \ref{eqn:better_eps_problem_k_mod_gcd2n2_a2mn}
so we can also pick the smallest $k_q^2 \in \ZZ_{>0}$ satisfying this condition,
which also guarantees that the gap $\frac{k}{2mn^2}$ is at least $\epsilon_{q,2}$.
\begin{theorem}[Bound on $r$ \#3]
\label{thm:rmax_with_eps1}
Let $v = (R,C,D)$ be a fixed Chern character. Then the ranks of the
pseudo-semistabilizers for $v$ with
$\chern_1^\beta = q = \frac{a_q}{n}$
are bounded above by the following expression (with $i=1$ or 2).
\begin{equation*}
\min
\left(
q^2,
2R\beta q
+C^2
-2DR
-2Cq
+q^2
+\frac{R}{\lcm(m,2n^2)}
Where $\epsilon_{q,i}$ is defined as in definition/lemma \ref{lemdfn:epsilon_q}.
\minorheading{Irrational $\beta$}
\egroup % end scope where beta redefined to beta_{-}
\section{Appendix - SageMath code}
\usemintedstyle{tango}
\inputminted[
obeytabs=true,
tabsize=2,
breaklines=true,
breakbefore=./
]{python}{filtered_sage.txt}