A Bridgeland stability condition $(Z,\mathcal{P})$ on a triangulated category $\mathcal{D}$ consists of a group homomorphism (‘central charge’) $Z$ from the (numerical) Grothendieck group $K(\mathcal{D})$ to $\mathbb{C}$, and full additive subcategories $\mathcal{P}(\phi)\subset\mathcal{D}$ for each $\phi\in\mathbb{R}$, whose objects are called ‘semistable objects of phase angle $\pi\phi$’,⁸⁸ 8 In the convention of Bridgeland, the phase is $\phi$. We have instead opted to call $\pi\phi$ the phase, which is more naturally identified with the phase angle of special Lagrangians. satisfying the following axioms:

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  (Phase) If $L\in\mathcal{P}(\phi)$ then $Z(L)=m(L)\exp(i\pi\phi)$ for some $m(L)>0$,

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  (Shift) For all $\phi\in\mathbb{R}$, $\mathcal{P}(\phi+1)=\mathcal{P}(\phi)[1]$,

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  (Monotonicity) If $\phi_{1}>\phi_{2}$ and $L_{j}\in\mathcal{P}(\phi_{j})$, $j=1,2$ then $Hom_{\mathcal{D}}(L_{1},L_{2})=0$,

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  For each nonzero object $L\in\mathcal{D}$ there are a finite sequence of real numbers $\phi_{1}>\phi_{2}>\ldots>\phi_{N}$ and a Harder-Narasimhan decomposition

  $$0=\mathcal{E}_{0}\to\mathcal{E}_{1}\to\ldots\to\mathcal{E}_{N}=L,$$

  (4)

  with distinguished triangles

  $$\mathcal{E}_{i-1}\to\mathcal{E}_{i}\to L_{i}\to\mathcal{E}_{i-1}[1]$$

  such that $L_{j}\in\mathcal{P}(\phi_{j})$.

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  (Calibration) For any fixed norm on the finite dimensional vector space $K(\mathcal{D})\otimes_{\mathbb{Z}}\mathbb{R}$, we have a uniform constant $C$, such that any semistable object $L$ satisfies $\left\lVert L\right\rVert\leq C|Z(L)|.$