diff --git a/figures/schmidt-arg-diag.pdf b/figures/schmidt-arg-diag.pdf index bc33ced3f77b5eb80beacc01db2c9bad727c0f8b..1b67aac2046843e094625420ef73385fa7845d4f 100644 Binary files a/figures/schmidt-arg-diag.pdf and b/figures/schmidt-arg-diag.pdf differ diff --git a/figures/schmidt-arg-diag.pdf_tex b/figures/schmidt-arg-diag.pdf_tex index 7f3ed3cea47e7f09dca2f99a92b621bf0a7a0822..7e33843985ead0de72a942d40efbff63d92bcbe3 100644 --- a/figures/schmidt-arg-diag.pdf_tex +++ b/figures/schmidt-arg-diag.pdf_tex @@ -57,7 +57,7 @@ \put(0.72051844,0.18401749){\color[rgb]{0,0,0}\makebox(0,0)[lt]{\lineheight{1.25}\smash{\begin{tabular}[t]{l}\textbf{$\chern_0(u)$}\end{tabular}}}}% \put(-0.00341324,0.92240317){\color[rgb]{0,0,0}\makebox(0,0)[lt]{\lineheight{1.25}\smash{\begin{tabular}[t]{l}\textbf{$\chern_2^{\beta_{-}}(u)$}\end{tabular}}}}% \put(0,0){\includegraphics[width=\unitlength,page=2]{schmidt-arg-diag.pdf}}% - \put(0.09550205,0.78995793){\color[rgb]{0,0,0.70980392}\rotatebox{-90.02923919}{\makebox(0,0)[lt]{\lineheight{1.25}\smash{\begin{tabular}[t]{l}\textbf{$\chern_0(u) \leq 0$}\end{tabular}}}}}% + \put(0.09550205,0.70529121){\color[rgb]{0,0,0.70980392}\rotatebox{-90.02923919}{\makebox(0,0)[lt]{\lineheight{1.25}\smash{\begin{tabular}[t]{l}\textbf{$\chern_0(u) \leq 0$}\end{tabular}}}}}% \put(0.29555381,0.06939285){\color[rgb]{0.49411765,0,0.49803922}\rotatebox{0.12466608}{\makebox(0,0)[lt]{\lineheight{1.25}\smash{\begin{tabular}[t]{l}\textbf{$\chern_2^{\beta_{-}}(u) \leq 0$}\end{tabular}}}}}% \put(0.35268151,0.97647054){\color[rgb]{0.6627451,0.11372549,0}\rotatebox{-44.62594593}{\makebox(0,0)[lt]{\lineheight{1.25}\smash{\begin{tabular}[t]{l}\textbf{$2\chern_0(u)\chern_2^{\beta_{-}}(u) \geq \chern_1^{\beta_{-}}(v)^2$}\end{tabular}}}}}% \end{picture}% diff --git a/figures/schmidt-arg-diag.svg b/figures/schmidt-arg-diag.svg index 4ad411a5b396f5f135315a4d64339f4f2bc7db63..7d80f170dcdc7551c9e012334cb0ef7b1bee4379 100644 --- a/figures/schmidt-arg-diag.svg +++ b/figures/schmidt-arg-diag.svg @@ -284,7 +284,7 @@ </g> <text xml:space="preserve" - transform="matrix(-1.3502221e-4,0.2645833,-0.2645833,-1.3502221e-4,46.737196,16.645156)" + transform="matrix(-1.3502221e-4,0.2645833,-0.2645833,-1.3502221e-4,46.737196,25.111828)" id="text7" style="font-weight:500;font-size:26.6667px;font-family:'FiraMono Nerd Font Mono';-inkscape-font-specification:'FiraMono Nerd Font Mono Medium';text-align:start;white-space:pre;shape-inside:url(#rect7);display:inline;fill:#0000b5;fill-opacity:1;stroke:none;stroke-width:4.71307;stroke-linecap:round;stroke-linejoin:round;stroke-miterlimit:3.2;stroke-dasharray:4.71307, 14.1392;stroke-dashoffset:0;stroke-opacity:1;paint-order:stroke fill markers"><tspan x="16.546875" diff --git a/tex/bounds-on-semistabilisers.tex b/tex/bounds-on-semistabilisers.tex index 13a6ce2c53a05a5f5a51065640492a0f1e25f01f..7e40decafc3054be26c81cb31a85601bf6fd6918 100644 --- a/tex/bounds-on-semistabilisers.tex +++ b/tex/bounds-on-semistabilisers.tex @@ -40,12 +40,12 @@ The Bogomolov form applied to the twisted Chern character is the same as the untwisted one. \noindent -\begin{minipage}{0.59\linewidth} +\begin{minipage}{0.57\linewidth} So $0 \leq \Delta(u)$ (condition 2 from Corollary \ref{cor:num_test_prob2}) yields: \begin{equation} \label{eqn-bgmlv-on-E} - 2\chern^\beta_0(u) \chern^\beta_2(u) \leq \chern^\beta_1(u)^2 + 2\chern_0(u) \chern^{\beta_{-}}_2(u) \leq \chern^{\beta_{-}}_1(u)^2 \end{equation} \noindent @@ -58,9 +58,10 @@ untwisted one. \end{equation} \noindent - The restrictions on $\chern^{\beta_-}_0(u)$ and $\chern^{\beta_-}_2(v)$ - is best seen with the following graph: - % TODO: hyperbola restriction graph (shaded) + The induced restrictions on possible pairs $\chern^{\beta_-}_0(u)$ and + $\chern^{\beta_-}_2(u)$, + as well as conditions 1 and 6 from Corollary \ref{cor:num_test_prob2} + are illustrated here on the right, with the invalid regions shaded. \end{minipage} \hfill \begin{minipage}{0.39\linewidth} @@ -71,40 +72,40 @@ untwisted one. \subimport{../figures/}{schmidt-arg-diag.pdf_tex} } \end{center} + \vspace{3pt} \end{minipage} -This is where the rationality of $\beta_{-}$ comes in. If -$\beta_{-} = \frac{a_v}{n}$ for some $a_v,n \in \ZZ$. -Then $\chern^{\beta_-}_2(E) \in \frac{1}{\lcm(m,2n^2)}\ZZ$. -In particular, since $\chern_2^{\beta_-}(E) > 0$ (by using $P=(\beta_-,0)$ in -lemma \ref{lem:pseudo_wall_numerical_tests}) we must also have -$\chern^{\beta_-}_2(E) \geq \frac{1}{\lcm(m,2n^2)}$, which then in turn gives a -bound for the rank of $E$: +Currently, the unshaded region in the diagram above, corresponding to possible +values for $\chern_0(u)$ and $\chern^{\beta_{-}}_2(u)$ that satisfy the +currently considered restrictions, is unbounded. +This is where the rationality of $\beta_{-}$ comes in. +If $\beta_{-} = \frac{a_v}{n}$ for some $a_v,n \in \ZZ$, +then $\chern^{\beta_-}_2(u) \in \frac{1}{\lcm(m,2n^2)}\ZZ$. +In particular, since $\chern_2^{\beta_-}(u) > 0$ we must also have +$\chern^{\beta_-}_2(u) \geq \frac{1}{\lcm(m,2n^2)}$, which then in turn gives a +bound for the rank of $u$: \begin{align} - \chern_0(E) &= \chern^{\beta_-}_0(E) \nonumber \\ - &\leq \frac{\lcm(m,2n^2) \chern^{\beta_-}_1(E)^2}{2} \nonumber \\ - &= \frac{mn^2 \chern^{\beta_-}_1(F)^2}{\gcd(m,2n^2)} + \chern_0(u) + &\leq \frac{\chern^{\beta_-}_1(u)^2}{2\chern^{\beta_{-}}_2(u)} \nonumber \\ + &\leq \frac{\lcm(m,2n^2) \chern^{\beta_-}_1(u)^2}{2} \nonumber \\ + &= \frac{mn^2 \chern^{\beta_-}_1(u)^2}{\gcd(m,2n^2)} \label{proof:first-bound-on-r} \end{align} - -In fact Equation \ref{eqn-tilt-cat-cond} can be tightened slightly: -we cannot have equality $\chern^{\beta_{-}}_1(E) = \chern^{\beta_{-}}_1(F)$ -otherwise we would have $\chern^{\beta_{-}}_1(G)=0$ for the quotient $G$. -This would imply $\mu(G)=\beta_{-}$, but since $\Theta_G$ is bounded above in the -upper-half plane by the assymptotes crossing the $\beta$-axis at $\pm45^\circ$ at -$\beta=\beta_{-}(v)$. So $\Theta_G$ cannot intersect $\Theta_v$ at any point -with $\alpha > 0$, so there is no point with $\nu(E)=\nu(F)=\nu(G)=0$, which would -have to hold at the top of the pseudo-wall if it were to exist. -Therefore we must have a strict inequality -$\chern^{\beta_{-}}_1(E) < \chern^{\beta_{-}}_1(F)$, -and since these are elements of $\frac{1}{n}\ZZ$, we can also conclude: +\noindent +Which we can then immediately bound using Equation \ref{eqn-tilt-cat-cond}. +Alternatively, given that +$\chern_1^{\beta_{-}}(u)$, $\chern_1^{\beta_{-}}(v)\in\frac{1}{n}\ZZ$, +we can tighten this bound on $\chern_1^{\beta_{-}}(u)$ given by that Equation to: +\[ + n\chern^{\beta_{-}}_1(u) \leq n\chern^{\beta_{-}}_1(v) - 1 +\] +allowing us to bound the expression in Equation \ref{proof:first-bound-on-r} to +the following: \[ - n\chern^{\beta_{-}}_1(E) \leq n\chern^{\beta_{-}}_1(F) - 1 + \chern_0(u) + &\leq \frac{m\left(n \chern^{\beta_-}_1(v) - 1\right)^2}{\gcd(m,2n^2)} \] -which then tightens the upper bound found for $\chern_0(E)$ -in Equation \ref{proof:first-bound-on-r} -to the bound in the statement of the Lemma. \end{proof}