structural:summarization, stylistic:tone
GARCH

σ t 2 = ω + α 1 ϵ t − 1 2 + ⋯ + α q ϵ t − q 2 + β 1 σ t − 1 2 + ⋯ + β p σ t − p 2 = ω + ∑ i = 1 q α i ϵ t − i 2 + ∑ i = 1 p β i σ t − i 2 {\displaystyle \sigma _{t}^{2}=\omega +\alpha _{1}\epsilon _{t-1}^{2}+\cdots +\alpha _{q}\epsilon _{t-q}^{2}+\beta _{1}\sigma _{t-1}^{2}+\cdots +\beta _{p}\sigma _{t-p}^{2}=\omega +\sum _{i=1}^{q}\alpha _{i}\epsilon _{t-i}^{2}+\sum _{i=1}^{p}\beta _{i}\sigma _{t-i}^{2}}