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Commit e3839a82 authored by Luke Naylor's avatar Luke Naylor
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Add plots with example of bounds on d for large r

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......@@ -585,19 +585,115 @@ radius of the circular wall must be positive. As discussed in (TODO ref), this
is equivalent to $\chern^{\beta}_2(E) > 0$, which yields:
\begin{sagesilent}
positive_radius_condition = (
(
(0 > - u.twist(beta).ch[2])
+ d # rearrange for d
)
.subs(solve(q == u.twist(beta).ch[1], c)[0]) # express c in term of q
.expand()
positive_radius_condition = (
(
(0 > - u.twist(beta).ch[2])
+ d # rearrange for d
)
.subs(solve(q == u.twist(beta).ch[1], c)[0]) # express c in term of q
.expand()
)
\end{sagesilent}
\begin{equation*}
\sage{positive_radius_condition}
\end{equation*}
\begin{sagesilent}
def beta_min(chern):
ts = stability.Tilt()
return min(
map(
lambda soln: soln.rhs(),
solve(
(ts.degree(chern))
.expand()
.subs(ts.alpha == 0),
beta
)
)
)
v_example = Chern_Char(3,2,-2)
q_example = 7/3
def plot_d_bound(v_example, q_example, ymax=5, ymin=-2, xmax=20):
# Equations to plot imminently representing the bounds on d:
eq1 = (
bgmlv1_d_lowerbound
.subs(R == v_example.ch[0])
.subs(C == v_example.ch[1])
.subs(D == v_example.ch[2])
.subs(beta = beta_min(v_example))
.subs(q == q_example)
)
eq2 = (
bgmlv2_d_upperbound
.subs(R == v_example.ch[0])
.subs(C == v_example.ch[1])
.subs(D == v_example.ch[2])
.subs(beta = beta_min(v_example))
.subs(q == q_example)
)
eq3 = (
bgmlv3_d_upperbound
.subs(R == v_example.ch[0])
.subs(C == v_example.ch[1])
.subs(D == v_example.ch[2])
.subs(beta = beta_min(v_example))
.subs(q == q_example)
)
eq4 = (
positive_radius_condition.rhs()
.subs(q == q_example)
.subs(beta = beta_min(v_example))
)
example_bounds_on_d_plot = (
plot(
eq3,
(r,v_example.ch[0],xmax),
color='green',
linestyle = "dashed",
legend_label=r"upper bound: $\Delta(G) \geq 0$",
title=r"$q :=\mathrm{ch}_1^{\beta_{-}}(E)=" + latex(q_example) + r"$"
)
+ plot(
eq2,
(r,0,xmax),
color='blue',
linestyle = "dashed",
legend_label=r"upper bound: $\Delta(E) \geq 0$"
)
+ plot(
eq4,
(r,0,xmax),
color='orange',
linestyle = "dotted",
legend_label=r"lower bound: $\mathrm{ch}_2^{\beta_{-}}(E)>0$"
)
+ plot(
eq1,
(r,v_example.ch[0]/2,xmax),
color='red',
linestyle = "dotted",
legend_label=r"lower bound: $\Delta(E) + \Delta(G) \leq \Delta(F)$"
)
)
example_bounds_on_d_plot.ymin(ymin)
example_bounds_on_d_plot.ymax(ymax)
example_bounds_on_d_plot.axes_labels(['$r$', '$d$'])
return example_bounds_on_d_plot
\end{sagesilent}
\sageplot{plot_d_bound(v_example, 0)}
\sageplot{plot_d_bound(v_example, 2)}
\sageplot{plot_d_bound(v_example, 4)}
\egroup
\section{Conclusion}
......
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