Variational Method


바닥 상태 에너지를 근사하는 계산법
실제의 경로는 action functional의 정류점에 존재한다는 원리(Stationary Action Principle)로부터 운동 방정식(Euler–Lagrange equation)을 유도
기울기 λ가 주어질 때, concave function *g(x) = log(x)*를 직선으로 근사
![](https://www.notion.so/image/https%3A%2F%2Fs3-us-west-2.amazonaws.com%2Fsecure.notion-static.com%2Fe3796093-2c41-4b6d-b2ff-111de07d708c%2FUntitled.png?table=block&id=8184a962-bd01-4309-9399-e0c32fb13cee&cache=v2)
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![](https://www.notion.so/image/https%3A%2F%2Fs3-us-west-2.amazonaws.com%2Fsecure.notion-static.com%2F72d6088a-dea0-4c5e-b99e-6c221e39fd6a%2FUntitled.png?table=block&id=906ba62c-a054-4ec4-b02a-313d3c15eced&cache=v2)
in this example, log 복잡성을 간단한 함수 x로 흡수



> [Variational Inference 알아보기 - MLE, MAP부터 ELBO까지](https://modulabs.co.kr/blog/variational-inference-intro/)

> [Variational method (quantum mechanics)](https://en.wikipedia.org/wiki/Variational_method_(quantum_mechanics))





