1. Klein-Gordon Equation The Klein-Gordon equation is a relativistic wave equation, related to the Schrödinger equation. It is second order in space and time and manifestly Lorentz covariant. It is a quantized version of the relativistic energy–momentum relation. Its solutions include a quantum scalar or pseudoscalar field, a field whose quanta are spinless particles. The […]
Wick’s theorem is a way to reduce a time-ordered operator into the sum of normal-ordered operator and various contractions. Then, where is the time-ordered operator from? Why we need this reduction?
Preface, July 21, Houston There’s no windows in our lab. Daylight passes without any signs left. Sometimes, I knew it’s pouring only when I stepped out this building. Or sometimes, the road was already dry, but the flowers under the crape myrtle trees told me a rain had just past. Eyesight began to drop again. […]
1. Regression Analysis Regression analysis is a statistical process for estimating the relationships between a dependent variable() and one or more independent variables(). That is, estimating the parameters (also called weights) in (1) based on some training examples . Regression analysis is widely used for prediction and forecasting, where its use has substantial overlap […]