7,146 research outputs found
Towards the generalized gravitational entropy for spacetimes with non-Lorentz invariant duals
Based on the Lewkowycz-Maldacena prescription and the fine structure analysis
of holographic entanglement proposed in arXiv:1803.05552, we explicitly
calculate the holographic entanglement entropy for warped CFT that duals to
AdS with a Dirichlet-Neumann type of boundary conditions. We find that
certain type of null geodesics emanating from the entangling surface
relate the field theory UV cutoff and the gravity IR
cutoff. Inspired by the construction, we furthermore propose an intrinsic
prescription to calculate the generalized gravitational entropy for general
spacetimes with non-Lorentz invariant duals. Compared with the RT formula,
there are two main differences. Firstly, instead of requiring that the bulk
extremal surface should be anchored on , we
require the consistency between the boundary and bulk causal structures to
determine the corresponding . Secondly we use the null geodesics
(or hypersurfaces) emanating from and normal to
to regulate in the bulk. We apply this prescription
to flat space in three dimensions and get the entanglement entropies
straightforwardly.Comment: 40pages,16 figures; v2 version improved, a discussion section added,
references added; v3 minor corrections, matching the published version on
JHE
Quantum dynamics in sine-square deformed conformal field theory: Quench from uniform to non-uniform CFTs
In this work, motivated by the sine-square deformation (SSD) for
(1+1)-dimensional quantum critical systems, we study the non-equilibrium
quantum dynamics of a conformal field theory (CFT) with SSD, which was recently
proposed to have continuous energy spectrum and continuous Virasoro algebra. In
particular, we study the time evolution of entanglement entropy after a quantum
quench from a uniform CFT, which is defined on a finite space of length , to
a sine-square deformed CFT. We find there is a crossover time that
divides the entanglement evolution into two interesting regions. For , the entanglement entropy does not evolve in time; for , the entanglement entropy grows as ,
which is independent of the lengths of the subsystem and the total system. This
growth with no revival indicates that a sine-square deformed CFT
effectively has an infinite length, in agreement with previous studies based on
the energy spectrum analysis. Furthermore, we study the quench dynamics for a
CFT with Mbius deformation, which interpolates between a
uniform CFT and a sine-square deformed CFT. The entanglement entropy oscillates
in time with period , with
corresponding to the uniform case and corresponding to the
SSD limit. Our field theory calculation is confirmed by a numerical study on a
(1+1)-d critical fermion chain.Comment: are welcome; 10 pages, 4 figures; v2: refs added; v3: refs added; A
physical interpretation of t* is added; v4: published version (selected as
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