5,943 research outputs found
Exploration of The Duality Between Generalized Geometry and Extraordinary Magnetoresistance
We outline the duality between the extraordinary magnetoresistance (EMR),
observed in semiconductor-metal hybrids, and non-symmetric gravity coupled to a
diffusive gauge field. The corresponding gravity theory may be
interpreted as the generalized complex geometry of the semi-direct product of
the symmetric metric and the antisymmetric Kalb-Ramond field:
(). We construct the four dimensional covariant
field theory and compute the resulting equations of motion. The equations
encode the most general form of EMR within a well defined variational
principle, for specific lower dimensional embedded geometric scenarios. Our
formalism also reveals the emergence of additional diffusive pseudo currents
for a completely dynamic field theory of EMR. The proposed equations of motion
now include terms that induce geometrical deformations in the device geometry
in order to optimize the EMR. This bottom-up dual description between EMR and
generalized geometry/gravity lends itself to a deeper insight into the EMR
effect with the promise of potentially new physical phenomena and properties.Comment: 13 pages and 6 figures. Revised/edited for clarity and purpose.
Several references added. Updated title based on suggestions and comments
received. Version accepted for publication in Phys.Rev.
The superconformal bootstrap for structure constants
We report on non-perturbative bounds for structure constants on N=4 SYM. Such
bounds are obtained by applying the conformal bootstrap recently extended to
superconformal theories. We compare our results with interpolating functions
suitably restricted by the S-duality of the theory. Within numerical errors,
these interpolations support the conjecture that the bounds found in this paper
are saturated at duality invariant values of the coupling. This extends recent
conjectures for the anomalous dimension of leading twist operators.Comment: 14 pages, 4 figure
Holographic Spacetimes as Quantum Circuits of Path-Integrations
We propose that holographic spacetimes can be regarded as collections of
quantum circuits based on path-integrals. We relate a codimension one surface
in a gravity dual to a quantum circuit given by a path-integration on that
surface with an appropriate UV cut off. Our proposal naturally generalizes the
conjectured duality between the AdS/CFT and tensor networks. This largely
strengthens the surface/state duality and also provides a holographic
explanation of path-integral optimizations. For static gravity duals, our new
framework provides a derivation of the holographic complexity formula given by
the gravity action on the WDW patch. We also propose a new formula which
relates numbers of quantum gates to surface areas, even including time-like
surfaces, as a generalization of the holographic entanglement entropy formula.
We argue the time component of the metric in AdS emerges from the density of
unitary quantum gates in the dual CFT. Our proposal also provides a heuristic
understanding how the gravitational force emerges from quantum circuits.Comment: 39 pages, 13 figures, latex; v2: appendix B added for an explicit
analysis of path-integral quantum circuits, counting scrambling quantum gates
clarified, references included; v3: a reference adde
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