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Holography of dislocations and ring defects in Einstein-Gauss-Bonnet AdS gravity

Vladimir Juričić, Olivera Miskovic, Francisca Ramírez Carrasco

Abstract

We study torsional topological defects in Einstein-Gauss-Bonnet gravity in ($4+1$)-dimensional anti-de Sitter spacetime. In the holographic interpretation, these correspond to crystalline dislocation defects associated with the discrete lattice translational symmetry. The Gauss-Bonnet coupling is fixed at the Chern-Simons point. By solving the equations of motion through an asymptotic expansion near the boundary, we show that the dual ($3+1$)-dimensional theory admits axially symmetric solutions. These solutions describe holographic materials with dislocation defects at finite temperature, encoded by a black hole in the bulk. At the same time, they feature ring-shaped defects arising from the background Riemann-Cartan geometry, characterized by nontrivial Burgers vectors. We also discuss the possible appearance of an odd-parity Abelian holographic anomaly, proportional to the Nieh-Yan invariant. Our results motivate further studies of holographic defects using bulk gravitational theories and support the view that torsion provides a holographic counterpart of crystalline dislocation defects.

Holography of dislocations and ring defects in Einstein-Gauss-Bonnet AdS gravity

Abstract

We study torsional topological defects in Einstein-Gauss-Bonnet gravity in ()-dimensional anti-de Sitter spacetime. In the holographic interpretation, these correspond to crystalline dislocation defects associated with the discrete lattice translational symmetry. The Gauss-Bonnet coupling is fixed at the Chern-Simons point. By solving the equations of motion through an asymptotic expansion near the boundary, we show that the dual ()-dimensional theory admits axially symmetric solutions. These solutions describe holographic materials with dislocation defects at finite temperature, encoded by a black hole in the bulk. At the same time, they feature ring-shaped defects arising from the background Riemann-Cartan geometry, characterized by nontrivial Burgers vectors. We also discuss the possible appearance of an odd-parity Abelian holographic anomaly, proportional to the Nieh-Yan invariant. Our results motivate further studies of holographic defects using bulk gravitational theories and support the view that torsion provides a holographic counterpart of crystalline dislocation defects.

Paper Structure

This paper contains 31 sections, 168 equations, 3 figures.

Figures (3)

  • Figure 1: Periodic solution with the strength of the torsion field given by Eq. \ref{['eq:periodic-sol']}: (Left) Temperature, $T=\frac{|c|}{\pi}\sqrt{\frac{m}{2}}$, with the mass of the black hole in Eq. \ref{['eq:mass-periodic']}, as a function of the dislocation parameter, $c$. (Center) The radius of the ring, $\bar{\rho}$, as given by Eqs. \ref{['bR']} and \ref{['R']}, as a function of the dislocation parameter, $c$. (Right) Dependence of the radius from the temperature, obtained from integrating out the dislocation parameter numerically.
  • Figure 2: Temperature (left) and the ring radius (center) as functions of the dislocation parameter $c$, as well as the dependence $\bar{\rho}(T)$ (right), in case of the non-periodic solution, the positive branch. The solution exists in the narrow interval $c_{02} \leq |c| <c_\infty$, as shown in Table \ref{['tab:critical points']}.
  • Figure 3: Temperature (left) and the ring radius (center) as functions of the dislocation parameter in the case of the non-periodic solution, the negative branch. The direct dependence $\bar{\rho}(T)$ (right). The solution exists in the interval $c_{02} \leq |c| <1$, as shown in Table \ref{['tab:critical points']}.