Ali Mollabashi

Holographic geometry of cMERA for quantum quenches and finite temperature

A bstractWe study the time evolution of cMERA (continuous MERA) under quantum quenches in free field theories. We calculate the corresponding holographic metric using the proposal in arXiv:1208.3469 and confirm that it qualitatively agrees with its gravity dual given by a half of the AdS black hole spacetime, argued by Hartman and Maldacena in arXiv:1303.1080. By doubling the cMERA for the quantum quench, we give an explicit construction of finite temperature cMERA. We also study cMERA in the presence of chemical potential and show that there is an enhancement of metric in the infrared region corresponding to the Fermi energy.

Fermions on Lifshitz Background

We study a non-relativistic fermionic retarded Green’s function by making use of a fermion on the Lifshitz geometry with critical exponent z = 2. With a natural boundary condition, respecting the symmetries of the model, the resultant retarded Green’s function exhibits a number of interesting features including a at band. We also study the

Holographic Mutual Information for Singular Surfaces

A bstractWe study corner contributions to holographic mutual information for entangling regions composed of a set of disjoint sectors of a single infinite circle in 3-dimensional conformal field theories. In spite of the UV divergence of holographic mutual information, it exhibits a first order phase transition. We show that tripartite information is also divergent for disjoint sectors, which is in contrast with the well-known feature of tripartite information being finite even when entangling regions share boundaries. We also verify the locality of corner effects by studying mutual information between regions separated by a sharp annular region. Possible extensions to higher dimensions and hyperscaling violating geometries is also considered for disjoint sectors.

Holographic aspects of two-charged dilatonic black hole in AdS5

A bstractWe study certain features of a strongly coupled theory whose gravitational dual is given by two-charge dilatonic black hole in AdS5 which has recently been used to study holographic Fermi liquids. By making use of the gravity description, we have studied conductivity, holographic entanglement entropy and dynamics of a charged scalar field. In particular at low energy we find that the temperature dependence of the real part of the conductivity goes as T3 and the background is stable against scalar condensations.

Entanglement in Lifshitz-type quantum field theories

A bstractWe study different aspects of quantum entanglement and its measures, including entanglement entropy in the vacuum state of a certain Lifshitz free scalar theory. We present simple intuitive arguments based on “non-local” effects of this theory that the scaling of entanglement entropy depends on the dynamical exponent as a characteristic parameter of the theory. The scaling is such that in the massless theory for small entangling regions it leads to area law in the Lorentzian limit and volume law in the z → ∞ limit. We present strong numerical evidences in (1+1) and (2+1)-dimensions in support of this behavior. In (2 + 1)-dimensions we also study some shape dependent aspects of entanglement. We argue that in the massless limit corner contributions are no more additive for large enough dynamical exponent due to non-local effects of Lifshitz theories. We also comment on possible holographic duals of such theories based on the sign of tripartite information.

Holographic Entanglement Entropy, Field Redefinition Invariance and Higher Derivative Gravity Theories

It is established that physical observables in local quantum field theories should be invariant under invertible field redefinitions. It is then expected that this statement should be true for the entanglement entropy and moreover that, via the gauge/gravity correspondence, the recipe for computing entanglement entropy holographically should also be invariant under local field redefinitions in the gravity side. We use this fact to fix the recipe for computing holographic entanglement entropy (HEE) for

Complexity growth with Lifshitz scaling and hyperscaling violation

f(R,{R}_{\ensuremath{\mu}\ensuremath{\nu}})

Holographic Subregion Complexity for Singular Surfaces

theories that could be mapped to Einstein gravity. An outcome of our prescription is that the surfaces that minimize the corresponding HEE functional for

Crystalline geometries from a fermionic vortex lattice

f(R,{R}_{\ensuremath{\mu}\ensuremath{\nu}})

On the Entanglement Between Interacting Scalar Field Theories

theories always have a vanishing trace of extrinsic curvature and that the HEE may be evaluated using the Wald entropy functional. We show that similar results follow from the FPS and Dong HEE functionals, for Einstein manifold backgrounds in