Entanglement spectrum of geometric states

The reduced density matrix of a given subsystem, denoted by rho (A), contains the information on subregion duality in a holographic theory. We may extract the information by using the spectrum (eigenvalue) of the matrix, called entanglement spectrum in this paper. We evaluate the density of eigenstates, one-point and two-point correlation functions in the microcanonical ensemble state rho (A,m) associated with an eigenvalue lambda for some examples, including a single interval and two intervals in vacuum state of 2D CFTs. We find there exists a microcanonical ensemble state with lambda (0) which can be seen as an approximate state of rho (A). The parameter lambda (0) is obtained in the two examples. For a general geometric state, the approximate microcanonical ensemble state also exists. The parameter lambda (0) is associated with the entanglement entropy of A and Renyi entropy in the limit n -> infinity. As an application of the above conclusion we reform the equality case of the Araki-Lieb inequality of the entanglement entropies of two intervals in vacuum state of 2D CFTs as conditions of Holevo information. We show the constraints on the eigenstates. Finally, we point out some unsolved problems and their significance on understanding the geometric states.

Automated summary

This study explores the application of entanglement spectrum in holographic theory, extracting information by evaluating the spectrum of the density matrix. It is found that there exists a microcanonical ensemble state associated with an approximate state of the density matrix, with specific parameter lambda (0) in some examples. The reformulation of the equality case of the Araki-Lieb inequality in terms of Holevo information is presented, along with constraints on the eigenstates and the significance of understanding geometric states.