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Commit cb98c26a authored by Luke Naylor's avatar Luke Naylor
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Complete corrections of part II

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......@@ -81,8 +81,8 @@ pseudo-semistabilisers for tilt stability.
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
then we must have $\chern^{\beta_-}_2(u) \in \frac{1}{\lcm(m,2n^2)}\ZZ$.
In particular, since $\chern_2^{\beta_-}(u) > 0$ we have
$\chern^{\beta_-}_2(u) \geq \frac{1}{\lcm(m,2n^2)}$, which then in turn gives a
bound for the rank of $u$:
......@@ -90,11 +90,11 @@ pseudo-semistabilisers for tilt stability.
\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)}
& = \frac{mn^2 \chern^{\beta_-}_1(u)^2}{\gcd(m,2n^2)}.
\label{proof:first-bound-on-r}
\end{align}
\noindent
Which we can then immediately bound using Equation \eqref{eqn-tilt-cat-cond}.
This can then immediately be bound using Equation \eqref{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:
......@@ -142,7 +142,7 @@ pseudo-semistabilisers for tilt stability.
Using the above Theorem \ref{thm:loose-bound-on-r}, we get that the ranks of
tilt semistabilisers for $v$ are bounded above by $\sage{extravagant.loose_bound}$.
However, when computing all tilt semistabilisers for $v$ on $\PP^2$, the maximum
rank that appears turns out to be $\sage{round(extravagant.actual_rmax, 1)}$.
rank that appears turns out to be $\sage{round(extravagant.actual_rmax)}$.
\end{example}
......@@ -180,8 +180,7 @@ of travel.
\qquad
\text{and}
\qquad
\chern_0(u) > \frac{q}{\mu(v) - \beta_0}.
\nonumber
\chern_0(u) > \frac{q}{\mu(v) - \beta_0}\cdot
\end{equation}
\noindent
......@@ -212,7 +211,7 @@ of travel.
$u=(r,c\ell,d\ell^2)$ with $r,c\in \ZZ$ and $d\in \frac{1}{\lcm(m,2)}\ZZ$ satisfying Equation
\eqref{lem:eqn:cond-for-fixed-q} is in fact a solution provided the remaining numerical conditions
1, 2, 3 and 6 are satisfied.
This is in essence the second part of the Lemma.
This is in essence the second part of the lemma.
\end{proof}
\begin{corollary}
......
......@@ -247,7 +247,7 @@ This could be due to a range of potential reasons:
For relatively small Chern characters (as those appearing in examples so far),
the difference in performance between the program \cite{NaylorRust2023} when
patched with the results of the different theorems above, do not show any
significant difference in performance. The earlier, weaker theorems occasionally
significant difference in performance, with the earlier, weaker theorems occasionally
producing the results marginally faster.
Note that this program patched with Theorem \ref{thm:loose-bound-on-r} will be
......@@ -271,8 +271,8 @@ indicators of the size of the bounds on the pseudo-semistabiliser ranks.
\caption{
Comparing the performance of program \cite{NaylorRust2023}
with different patches corresponding to the results of Theorems
\ref{thm:loose-bound-on-r}
\ref{thm:rmax_with_uniform_eps}
\ref{thm:loose-bound-on-r},
\ref{thm:rmax_with_uniform_eps},
\ref{thm:rmax_with_eps1}
when computing solutions to Problem \ref{problem:problem-statement-2}
for $(45,54\ell,-41\frac{\ell^2}{2})$
......@@ -304,6 +304,6 @@ versus the average looser.
However, the actual ratio in the benchmark shown in Figure \ref{fig:benchmark}
between the two instances of the program patched with the two corresponding
bounds is around 0.6 instead.
Not as good as the improvement on the bound, however still not insignificant
This is not as good as the improvement on the bound, however it is still not insignificant
for examples with larger `$n$'-value, where the execution time will
potentially be in the order of minutes, or even hours.
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