Loop Corrections in Double Field Theory: Non-trivial Dilaton Potentials

It is believed that the invariance of the generalised diffeomorphisms prevents any non-trivial dilaton potential from double field theory. It is therefore difficult to include loop corrections in the formalism. We show that by redefining a non-local dilaton field, under strong constraint which is necessary to preserve the gauge invariance of double field theory, the theory does permit non-constant dilaton potentials and loop corrections. If the fields have dependence on only one single coordinate, the non-local dilaton is identical to the ordinary one with an additive constant.Comment: V3, 11 pages, references added, typos corrected, version to appear in JHE

The dual geometries of TTˉT\bar{T} deformed CFT2_2 and highly excited states of CFT2_2

In previous works, we have developed an approach to derive the pure AdS$_3$ and BTZ black hole from the entanglement entropies of the free CFT$_2$ and finite temperature CFT$_2$, respectively. We exclusively use holographic principle only and make no restriction about the bulk geometry, not only the kinematics but also the dynamics. In order to verify the universality and correctness of our method, in this paper, we apply it to the $T\bar{T}$ deformed CFT$_2$, which breaks the conformal symmetry. In terms of the physical arguments of the $T\bar{T}$ deformed CFT$_2$, the derived metric is a deformed BTZ black hole. The requirement that the CFT$_2$ lives on a conformally flat boundary leads to $r_{c}^{2}=\ 6R_{AdS}^{4}/(\pi c\mu)$ naturally, in perfect agreement with previous conjectures in literature. The energy spectum and propagation speed calculated with this deformed BTZ metric are the same as these derived from $T\bar{T}$ deformed CFT$_2$. We furthermore calculate the dual geometry of highly excited states with our approach. The result contains the descriptions for the conical defect and BTZ black hole.Comment: V2, 14 pages, 2 figures. references added. arXiv admin note: text overlap with arXiv:1809.0135

Holographic DC Conductivity for Backreacted Nonlinear Electrodynamics with Momentum Dissipation

We consider a holographic model with the charge current dual to a general nonlinear electrodynamics (NLED) field. Taking into account the backreaction of the NLED field on the geometry and introducing axionic scalars to generate momentum dissipation, we obtain expressions for DC conductivities with a finite magnetic field. The properties of the in-plane resistance are examined in several NLED models. For Maxwell-Chern-Simons electrodynamics, negative magneto-resistance and Mott-like behavior could appear in some parameter space region. Depending on the sign of the parameters, we expect the NLED models to mimic some type of weak or strong interactions between electrons. In the latter case, negative magneto-resistance and Mott-like behavior can be realized at low temperatures. Moreover, the Mott insulator to metal transition induced by a magnetic field is also observed at low temperatures.Comment: 28 pages, 31 figures. Added reference