Eugenio Megias

Anomalous Transport from Kubo Formulae

Chiral anomalies have profound impact on the transport properties of relativistic fluids. In four dimensions there are different types of anomalies, pure gauge and mixed gauge-gravitational anomalies. They give rise to two new non-dissipative transport coefficients, the chiral magnetic conductivity and the chiral vortical conductivity. They can be calculated from the microscopic degrees of freedom with the help of Kubo formulae. We review the calculation of the anomalous transport coefficients via Kubo formulae with a particular emphasis on the contribution of the mixed gauge-gravitational anomaly.

Holographic gravitational anomaly in first and second order hydrodynamics

A bstractWe compute, in the framework of the fluid/gravity correspondence, the transport coefficients of a relativistic fluid affected by chiral and gauge-gravitational anomalies, including external electromagnetic fields. The computation is performed at first and second order in the hydrodynamical expansion. We use a 5-dim holographic model with pure gauge and mixed gauge-gravitational Chern-Simons terms in the action. We reproduce at first order previous results on the anomaly induced current of a magnetic field and a vortex in a relativistic fluid, and compute at second order the anomalous and non anomalous transport coefficients by using a Weyl covariant formalism. We find a dissipative and anomalous correction to the chiral magnetic conductivity due to the time dependence of the magnetic field. We also find a new contribution from the mixed gauge-gravitational anomaly to the shear waves dispersion relation. The role played by the chiral and gravitational anomalies in other transport coefficients is discussed.

Naturally light dilatons from nearly marginal deformations

A bstractWe discuss the presence of a light dilaton in CFTs deformed by a nearlymarginal operator O

Second-order partition function of a non-interacting chiral fluid in 3+1 dimensions

\mathcal{O}

Fluid/Gravity Correspondence, Second Order Transport and Gravitational Anomaly

, in the holographic realizations consisting of confining RG flows that end on a soft wall. Generically, the deformations induce a condensate O

A holographic realization of light dilatons

\left\langle \mathcal{O}\right\rangle