Glauber-Sudarshan P-representation

The Glauber-Sudarshan P-representation is a mathematical tool used in quantum optics to express the state of light as a weighted sum of idealized, classical-like states called coherent states. Think of it as breaking down complex quantum light sources into a mix of basic, more understandable "classical" components, with the weights telling us how much of each component is present. This helps physicists analyze, interpret, and compare quantum light behavior with everyday classical light, providing insight into the quantum-classical boundary and the nature of light in different states.