Magnetic Black Branes and their Quasi Normal Modes as a tool for studying Quantum correlations.

The AdS/CFT correspondence has been proved to be a useful  tool for studying correlations in Quantum field theory (QFT). As an example, I computed one point correlator (expectation value) of a current in different equilibrium states of the system. To compute these correlators, I studied the quasi normal modes of magnetic black branes in an asymptotic AdS spacetime. According to the correspondence, the quasi normal modes on the boundary are equivalent to the one point correlator of the operator that is dual to the perturbed field.

In the first part of my talk I will provide some theoretical background. This will include a brief presentation of the four-dimensional N=4 super Yang-Mills theory, which is the QFT under discussion. I will then state the duality conjecture that leads to the duality dictionary and outline the steps required to compute one point correlators. Finally, in this section, I will introduce the Einstein-Maxwell theory that was used for the computation.

In the second part of my talk I will present the computation I performed and the obtained results. The computation heavily relied on using symmetry considerations to simplify the equations of motion, which turned out to be second-order ordinary differential equations. In order to obtain analytical results, certain limits are taken. In the general case, numerical computations are required to compute the quasi normal modes and their frequencies.