diff --git a/tex/bounds-on-semistabilisers.tex b/tex/bounds-on-semistabilisers.tex index b967fa2a0a9e5da659b6c3f52ee0c58f992560bd..811e3c96fae61859ad2c2d188be67ff18cb486ad 100644 --- a/tex/bounds-on-semistabilisers.tex +++ b/tex/bounds-on-semistabilisers.tex @@ -297,9 +297,10 @@ condition $\chern_2^P(u) = \sage{problem1.radius_condition_before_sub}$ yields: Expanding $\chern^{\beta_0}_2(u)$ in terms of $r$, $c$, $d$, and rearranging for $d$ then yields: -\begin{equation*} +\begin{equation} + \label{eqn:radius_condition_d_bound} \sage{problem1.radius_condition_d_bound} -\end{equation*} +\end{equation} \subsubsection{Semistability of the Semistabilizer: @@ -360,14 +361,78 @@ from plots_and_expressions import bgmlv3_d_upperbound_terms \end{equation} \noindent -If $r=R$, then $\Delta(v-u)=(C-c)^2 \geq 0$ is always true, and for $r<R$ it gives a lower -bound on $d$, but it is weaker than the one given by the lower bound +If $r=R$, then $\Delta(v-u)=(C-c)^2 \geq 0$ is always true, and for $r<R$ +the expression on the right hand side of Equation \ref{eqn-bgmlv3_d_upperbound} +gives a lower bound for $d$ instead. +However it is weaker than lower bound given by $\chern^P_2(u)>0$ if $u$ already satisfies Equations -\ref{lem:eqn:cond-for-fixed-q}. -We see this by comparing the unique terms from either bound: +\ref{lem:eqn:cond-for-fixed-q} as will be shown now: - -{\color{red} THIS IS BECAUSE TODO} +Since $r, R-r>0$, we have: +\begin{equation} + \label{lem:proof:slope-order-rltR} + \beta_0, \mu(u) < \mu(v) < \mu(v-u) +\end{equation} +\noindent +The first inequality coming from $P \in \Theta_v^{-}$ and Equation +\ref{lem:eqn:cond-for-fixed-q}, and the second inequality following by the +see-saw principle. +% TODO maybe cover the see-saw principle +\begin{align*} + \left( + \frac{\chern^{\beta_0}_1(v-u)}{\chern_0(v-u)} + \right)^2 + &= + \left( + \mu(v-u) - \beta_0 + \right)^2 +\\ + &> + \left( + \mu(v) - \beta_0 + \right)^2 + &\text{by Equation \ref{lem:proof:slope-order-rltR}} +\\ + &= + \left( + \frac{\chern^{\beta_0}_1(v)}{\chern_0(v)} + \right)^2 +\\ + &\geq + 2 \frac{\chern^{\beta_0}_2(v)}{\chern_0(v)} + &\text{since }\Delta(v) \geq 0 + \:\text{and }\chern_0(v) > 0 +\\ + \frac{ + \left( + q-\chern^{\beta_0}_1(v) + \right)^2 + }{ + \left( + R-r + \right)^2 + } + &> + 2 \frac{\chern^{\beta_0}_2(v)}{R} +\\ + \chern_2^{\beta_0}(v) + - \frac{ + \left( + q-\chern^{\beta_0}_1(v) + \right)^2 + }{ + 2\left( + R-r + \right) + } + &< + \frac{r\chern^{\beta_0}_2(v)}{R} +\end{align*} +\noindent +Showing that the unique terms of Equation +\ref{eqn:radius_condition_d_bound} +are greater than those of Equation +\ref{eqn-bgmlv3_d_upperbound}. \subsubsection{All Bounds on \texorpdfstring{$d$}{d} Together for Problem