Depression is a serious mental disorder affecting millions of people all over the world. Traditional clinical diagnosis methods are subjective, complicated and require extensive participation clinicians. Recent advances in automatic depression analysis systems promise future where these shortcomings addressed by objective, repeatable, readily available diagnostic tools to aid health professiona...

The many-body problem is usually approached from one of two perspectives: the first originates an action and based on Feynman diagrams, second centered around a Hamiltonian deals with quantum states operators. connection between results obtained in either way made through spectral (or Lehmann) representations, well known for two-point correlation functions. Here, we complete this picture by der...