diff --git a/main.tex b/main.tex index b316fa80e615a19d4765c69cbf456815cf9f8f0e..ac2e57e6e333187ab336f077d83c4bf0a78b2cd3 100644 --- a/main.tex +++ b/main.tex @@ -229,6 +229,7 @@ This can be rearranged to express a bound on $d$ as follows: \end{sagesilent} \begin{dmath} + \label{eqn-bgmlv1_d_lowerbound} \sage{bgmlv1_d_ineq} \end{dmath} @@ -242,33 +243,40 @@ This can be rearranged to express a bound on $d$ as follows: assert bgmlv1_d_lowerbound_const_term == v.twist(beta_min).ch[2]/2 + beta_min*q, "fail" assert bgmlv1_d_lowerbound_linear_term == (v.twist(beta_min).ch[2]/2 + beta_min^2/2 + beta_min*q)*r, "fail" - foo = ( + assert bgmlv1_d_lowerbound_exp_term == ( - 2*R*v.twist(beta_min).ch[2] - 3*R^2*beta_min^2 - 4*R*beta_min*q + C*q - q^2 - ).expand()/(R-2*r) - foo = ( + ).expand()/(R-2*r), "fail" + + assert bgmlv1_d_lowerbound_exp_term == ( - 2*D*R + (C^2)/4 - ((C - 4*R*beta_min)/2 - q)^2 - ).expand()/(R-2*r) - foo = ( + ).expand()/(R-2*r), "fail" + + assert bgmlv1_d_lowerbound_exp_term == ( (2*R*beta_min + q) *(2*R*beta_min + q - C) + 2*D*R - ).expand()/(2*r - R) + ).expand()/(2*r - R), "fail" \end{sagesilent} -\begin{equation} - \sage{bgmlv1_d_lowerbound_exp_term} -\end{equation} -\begin{equation} - \sage{foo} -\end{equation} - \noindent -In the case $\beta = \beta_{-}$ (or $\beta_{+}$) this can be simplified. +Viewing equation \ref{eqn-bgmlv1_d_lowerbound} as a lower bound for $d$ given +as a function of $r$, the terms can be rewritten as follows. +The constant term in $r$ is +$\chern^{\beta}_2(F) + \beta q$. +The linear term in $r$ is +$(\chern^{\beta}_2(F)/2 + \beta^2/2 + \beta q)r$. +Finally, there's an hyperbolic term in $r$ which tends to 0 as $r \to \infty$, +and can be written: +$\frac{-2R\chern^{\beta}_2(F) - 3R^2\beta^2 - 4Rq\beta + Cq - q^2}{R-2r}$ or +$\frac{(2R\beta + q)(2R\beta + q - C) + 2DR}{2r-R}$. +In the case $\beta = \beta_{-}$ (or $\beta_{+}$) we have +$\chern^{\beta}_2(F) = 0$, +so some of these expressions simplify. \subsection{$\Delta(E) \geq 0$}