diff --git a/main.tex b/main.tex index 634c09041854b6dd7a108eb17a695eff0f5939c1..f26a6c4cc02142a3d13e8e09c9e077dbd5d5997f 100644 --- a/main.tex +++ b/main.tex @@ -1361,7 +1361,7 @@ considering equations \bgroup \let\originalepsilon\epsilon -\renewcommand\epsilon{{\originalepsilon_{F}}} +\renewcommand\epsilon{{\originalepsilon_{v}}} \begin{sagesilent} var("epsilon") @@ -1549,8 +1549,8 @@ Next, we seek to find a larger $\epsilon$ to use in place of $\epsilon_F$ in the proof of theorem \ref{thm:rmax_with_uniform_eps}: \begin{lemmadfn}[ - Finding better alternatives to $\epsilon_F$: - $\epsilon_{q,1}$ and $\epsilon_{q,2}$ + Finding a better alternative to $\epsilon_v$: + $\epsilon_{v,q}$ ] \label{lemdfn:epsilon_q} Suppose $d \in \frac{1}{2}\ZZ$ satisfies the condition in @@ -1564,39 +1564,23 @@ proof of theorem \ref{thm:rmax_with_uniform_eps}: \noindent Then we have: - \begin{equation*} + \begin{equation} + \label{eqn:epsilon_q_lemma_prop} d - \frac{(\aa r + 2\bb)\aa}{2n^2} - \geq \epsilon_{q,2} \geq \epsilon_{q,1} > 0 -\end{equation*} + \geq \epsilon_{v,q} \geq \epsilon_v > 0 + \end{equation} -Where $\epsilon_{q,1}$ and $\epsilon_{q,2}$ are defined as follows: + \noindent + Where $\epsilon_{v,q}$ is defined as follows: -\begin{equation*} - \epsilon_{q,1} := - \frac{k_{q,1}}{2n^2} - \qquad - \epsilon_{q,2} := - \frac{k_{q,2}}{2n^2} -\end{equation*} -\begin{align*} - \text{where } - &k_{q,1} \text{ is the least } - k\in\ZZ_{>0}\: s.t.:\: - k \equiv -\aa\bb \mod n -\\ - &k_{q,2} \text{ is the least } - k\in\ZZ_{>0}\: s.t.:\: - k \equiv \aa\bb (\aa\aa^{'}-2) - \mod n\gcd(n,\aa^2) -\end{align*} + \begin{equation*} + \epsilon_{v,q} := + \frac{k_{q}}{2n^2} + \end{equation*} + with $k_{v,q}$ being the least $k\in\ZZ_{>0}$ satisfying $k \equiv -\aa\bb \mod n$ \end{lemmadfn} -It is worth noting that $\epsilon_{q,2}$ is potentially larger than -$\epsilon_{q,1}$ -but calculating it involves a $\gcd$, a modulo reduction, and a modulo $n$ -inverse, for each $q$ considered. - \begin{proof} Consider the following: @@ -1621,9 +1605,9 @@ Consider the following: &\equiv k && \mod n^2 \\ &\Longrightarrow& - \aa^2 \aa^{'}\bb - 2\aa\bb + \aa^2 \aa^{-1}\bb - 2\aa\bb &\equiv k && - \mod \gcd(n^2, \aa^2 n) + \mod n \label{eqn:better_eps_problem_k_mod_gcd2n2_a2mn} \\ &\Longrightarrow& -\aa\bb @@ -1637,12 +1621,11 @@ 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 $\frac{k}{2n^2}$ 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 $\frac{k}{2n^2}$ is at least $\epsilon_{q,2}$. +We are then guaranteed that $k_{v,q}$ is less than any $k$ satisfying eqn +\ref{eqn:finding_better_eps_problem}, giving the first inequality in eqn +\ref{eqn:epsilon_q_lemma_prop}. +Furthermore, $k_{v,q}\geq 1$ gives the second part of the inequality: +$\epsilon_{v,q}\geq\epsilon_v$, with equality when $k_{v,q}=1$. \end{proof} @@ -1653,14 +1636,14 @@ which also guarantees that the gap $\frac{k}{2n^2}$ is at least $\epsilon_{q,2}$ rational and expressed in lowest terms. Then the ranks $r$ of the pseudo-semistabilizers $u$ for $v$ with $\chern_1^\beta(u) = q = \frac{b_q}{n}$ - are bounded above by the following expression (with $i=1$ or $2$). + are bounded above by the following expression: \begin{sagesilent} var("delta", domain="real") # placeholder symbol to be replaced by k_{q,i} \end{sagesilent} \bgroup - \def\kappa{k_{q,i}} + \def\kappa{k_{v,q}} \def\psi{\chern_1^{\beta}(F)} \begin{align*} \min @@ -1670,7 +1653,7 @@ var("delta", domain="real") # placeholder symbol to be replaced by k_{q,i} \right) \end{align*} \egroup - Where $k_{q,i}$ is defined as in definition/lemma \ref{lemdfn:epsilon_q}, + Where $k_{v,q}$ is defined as in definition/lemma \ref{lemdfn:epsilon_q}, and $R = \chern_0(v)$ Furthermore, if $\aa \not= 0$ then @@ -1683,12 +1666,11 @@ var("delta", domain="real") # placeholder symbol to be replaced by k_{q,i} Just like in examples \ref{exmpl:recurring-first} and \ref{exmpl:recurring-second}, take $\ell=c_1(\mathcal{O}(1))$ as the standard polarization on $\PP^2$, so that -$m=2$, $\beta=\sage{recurring.b}$, giving $n=\sage{recurring.b.denominator()}$ +$\beta=\sage{recurring.b}$, giving $n=\sage{recurring.b.denominator()}$ and $\chern_1^{\sage{recurring.b}}(F) = \sage{recurring.twisted.ch[1]}$. %% TODO transcode notebook code -Using the above theorem \ref{thm:rmax_with_eps1}, -TODO fill in values -\end{example} +The (non-exclusive) upper bounds for $r:=\chern_0(u)$ of a tilt semistabilizer $u$ of $v$ +in terms of the possible values for $q:=\chern_1^{\beta}(u)$ are as follows: \begin{sagesilent} import numpy as np @@ -1705,41 +1687,27 @@ def bound_comparisons(example): + n^2*(v_twisted.ch[1] - q_val)^2/k )) - def k_1(n, a_v, b_q): + def k(n, a_v, b_q): n = int(n) a_v = int(a_v) b_q = int(b_q) k = -a_v*b_q % n return k if k > 0 else k + n - def k_2(n, a_v, b_q): - n = int(n) - a_v = int(a_v) - b_q = int(b_q) - a_v_inv = inverse_mod(a_v, n) - modulo = n*gcd(n, a_v^2) - k = (a_v^2*a_v_inv*b_q - 2*a_v*b_q) % modulo - return k if k > 0 else k + modulo - b_qs = list(range(example.twisted.ch[1]*n+1)) qs = list(map(lambda x: x/n,b_qs)) - k_1s = list(map(lambda b_q: k_1(n, a_v, b_q), b_qs)) - k_2s = list(map(lambda b_q: k_2(n, a_v, b_q), b_qs)) + ks = list(map(lambda b_q: k(n, a_v, b_q), b_qs)) theorem2_bounds = [ theorem_bound(example.twisted, q_val, 1) for q_val in qs ] - theorem31_bounds = [ - theorem_bound(example.twisted, q_val, k) - for q_val, k in zip(qs,k_1s) - ] - theorem32_bounds = [ + theorem3_bounds = [ theorem_bound(example.twisted, q_val, k) - for q_val, k in zip(qs,k_2s) + for q_val, k in zip(qs,ks) ] - return qs, theorem2_bounds, theorem31_bounds, theorem32_bounds + return qs, theorem2_bounds, theorem3_bounds -qs, theorem2_bounds, theorem31_bounds, theorem32_bounds = bound_comparisons(recurring) +qs, theorem2_bounds, theorem3_bounds = bound_comparisons(recurring) \end{sagesilent} \directlua{ table_width = 3*4+1 } @@ -1756,20 +1724,20 @@ end} tex.sprint(cell) end} \\ - Thm \ref{thm:rmax_with_eps1} (i=1) + Thm \ref{thm:rmax_with_eps1} \directlua{for i=0,table_width-1 do - local cell = [[&$\noexpand\sage{theorem31_bounds[]] .. i .. "]}$" - tex.sprint(cell) -end} - \\ - Thm \ref{thm:rmax_with_eps1} (i=2) -\directlua{for i=0,table_width-1 do - local cell = [[&$\noexpand\sage{theorem32_bounds[]] .. i .. "]}$" + local cell = [[&$\noexpand\sage{theorem3_bounds[]] .. i .. "]}$" tex.sprint(cell) end} \end{tabular} -\minorheading{Irrational $\beta$} +It's worth noting that the bounds given by theorem \ref{thm:rmax_with_eps1} +reach, but do not exceed the actual maximum rank 25 of the +pseudo-semistabilizers of $v$ in this case. +As a reminder, the original loose bound from theorem \ref{thm:loose-bound-on-r} +was 144. + +\end{example} \egroup % end scope where beta redefined to beta_{-}