KDA memory decay uses radioactive-style half-life math, with 69-token lifetime at α=0.99

CatAstro_Piyush · x · 2026-07-29

KDA’s memory decay follows the same half-life math as radioactive decay: if a channel evolves as Sn = α^n S0, then its half-life is n½ = ln(0.5) / ln(α). The post notes that α = 0.99 gives a half-life of about 69 tokens.

The attached formula image shows KDA learning different decay parameters across memory channels, so each channel can operate on its own timescale. In other words, the model is not using one universal memory horizon, but a set of learned ones.

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