diff --git a/main.tex b/main.tex index 32b58237c3354d56072d12b7ca7dcbeb1c0d8326..502ee04fb148c3026b0b3eff3dbe803c055d4d27 100644 --- a/main.tex +++ b/main.tex @@ -113,12 +113,27 @@ bounds on $\chern_0(E)$ of potential destabilizers $E$ of $F$. Characters} \begin{dfn}[Pseudo-semistabilizers] - Given a Chern Character $v$, and a given stability condition $\sigma$, + Given a Chern Character $v$ on a Picard rank 1 surface, and a given stability + condition $\sigma_{\alpha,\beta}$, a pseudo-semistabilizing $u$ is a `potential' Chern character: \[ u = \left(r, c\ell, d \frac{1}{2} \ell^2\right) \] - which has the same tilt slope as $v$: $\mu_{\sigma}(u) = \mu_{\sigma}(v)$. + which has the same tilt slope as $v$: $\nu_{\alpha,\beta}(u) = \nu_{\alpha,\beta}(v)$. + + \noindent + Furthermore the following Bogomolov-Gieseker inequalities are satisfied: + \begin{itemize} + \item $\Delta(u) \geq 0$ + \item $\Delta(v-u) \geq 0$ + \item $\Delta(u) + \Delta(v-u) \leq \Delta(v)$ + \end{itemize} + \noindent + And finally these two conditions are satisfied: + \begin{itemize} + \item $\chern_1^{\beta}(u) \geq 0$ + \item $\chern_1^{\beta}(v-u) \geq 0$ + \end{itemize} Note $u$ does not need to be a Chern character of an actual sub-object of some object in the stability condition's heart with Chern character $v$. @@ -128,6 +143,14 @@ At this point, and in this document, we do not care about whether pseudo-semistabilizers are even Chern characters of actual elements of $\bddderived(X)$, some other sources may have this extra restriction too. +\begin{lemma}[ Sanity check for Pseudo-semistabilizers ] + Given a Picard rank 1 surface, and a given stability + condition $\sigma_{\alpha,\beta}$, + if $E\hookrightarrow F\twoheadrightarrow G$ is a semistabilizing sequence in + $\firsttilt\beta$ for $F$. + Then $\chern(E)$ is a pseudo-semistabilizer of $\chern(F)$ +\end{lemma} + Considering the stability conditions with two parameters $\alpha, \beta$ on Picard rank 1 surfaces. We can draw 2 characteristic curves for any given Chern character $v$ with @@ -606,7 +629,7 @@ Fix a Chern character $v$ with positive rank, $\Delta(v) \geq 0$, and $\beta_{-}(v) \in \QQ$. The goal is to find all Chern characters $u=(r,c\ell,d\ell^2)$ which satisfy the conditions of lemma \ref{lem:pseudo_wall_numerical_tests} using -$P=(\beta_{-},0)$, as well as the Bogomolov inequalities: +$P=(\beta_{-},0)$, $\chern_1^{\beta_{-}}(v-u)\geq 0$, as well as the Bogomolov inequalities: $\Delta(u),\Delta(v-u) \geq 0$ and $\Delta(u)+\Delta(v-u) \leq \Delta(v)$. We want to restrict our attention to pseudo-walls left of $V_v$ (condition (a) of lemma), because this is the side of $V_v$ containing the chamber for Gieseker