We prove a product formula for $\delta$-invariant and as an application, we show that product of K-(semi, poly)stable Fano varieties is also K-(semi, poly)stable.

中文翻译：

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K 稳定性的乘积定理

我们证明了$\delta$-invariant 的乘积公式，并且作为应用，我们证明了K-(semi, poly)stable Fano 品种的乘积也是K-(semi, poly)stable。