We compute the left-right entanglement entropy for Dp-branes in string theory. We employ the CFT approach to string theory Dp-branes, in particular, its presentation as coherent states of the closed string sector. The entanglement entropy is computed as the von Neumann entropy for a density matrix resulting from integration over the left-moving degrees of freedom. We discuss various crucial ambiguities related to sums over spin structures and argue that different choices capture different physics; however, we advance a themodynamic argument that seems to favor a particular choice of replica. We also consider Dp branes on compact dimensions and verify that the effects of T-duality act covariantly on the Dp brane entanglement entropy. We find that generically the left-right entanglement entropy provides a suitable generalization of boundary entropy and of the D-brane tension.We compute the left-right entanglement entropy for Dp-branes in string theory. We employ the CFT approach to string theory Dp-branes, in particular, its presentation as coherent states of the closed string sector. The entanglement entropy is computed as the von Neumann entropy for a density matrix resulting from integration over the left-moving degrees of freedom. We discuss various crucial ambiguities related to sums over spin structures and argue that different choices capture different physics; however, we advance a themodynamic argument that seems to favor a particular choice of replica. We also consider Dp branes on compact dimensions and verify that the effects of T-duality act covariantly on the Dp brane entanglement entropy. We find that generically the left-right entanglement entropy provides a suitable generalization of boundary entropy and of the D-brane tension.

Journal of High Energy PhysicsNov 1, 201612 citations

Left-right entanglement entropy for a Dp-brane with dynamics and background fields

Shirin Teymourtashlou, Davoud Kamani

Abstract We investigate the left-right entanglement entropy of a boundary state, corresponding to a dynamical Dp-brane with the internal and background fields. We assume that the brane has a tangential linear motion and a rotation, and is dressed with an internal U(1) gauge potential and the Kalb–Ramond tensor field $B_{\mu \nu }$ Bμν . We derive the entanglement entropy via the Rényi entropy by applying the replica trick. Our calculations will be in the context of the bosonic string theory.Abstract We investigate the left-right entanglement entropy of a boundary state, corresponding to a dynamical Dp-brane with the internal and background fields. We assume that the brane has a tangential linear motion and a rotation, and is dressed with an internal U(1) gauge potential and the Kalb–Ramond tensor field $$B_{\mu \nu }$$ Bμν . We derive the entanglement entropy via the Rényi entropy by applying the replica trick. Our calculations will be in the context of the bosonic string theory.

arXiv:2004.06981The European Physical Journal CApr 1, 20203 citations

Left-right entanglement entropy of boundary states

Leopoldo A. Pando Zayas, Norma Quiroz

We study entanglement entropy of boundary states in a free bosonic conformal field theory. A boundary state can be thought of as composed of a particular combination of left and right-moving modes of the two-dimensional conformal field theory. We investigate the reduced density matrix obtained by tracing over the right-moving modes in various boundary states. We consider Dirichlet and Neumann boundary states of a free noncompact as well as a compact boson. The results for the entanglement entropy indicate that the reduced system can be viewed as a thermal CFT gas. Our findings are in agreement and generalize results in quantum mechanics and quantum field theory where coherent states can also be considered. In the compact case we verify that the entanglement entropy expressions are consistent with T-duality.We study entanglement entropy of boundary states in a free bosonic conformal field theory. A boundary state can be thought of as composed of a particular combination of left and right-moving modes of the two-dimensional conformal field theory. We investigate the reduced density matrix obtained by tracing over the right-moving modes in various boundary states. We consider Dirichlet and Neumann boundary states of a free noncompact as well as a compact boson. The results for the entanglement entropy indicate that the reduced system can be viewed as a thermal CFT gas. Our findings are in agreement and generalize results in quantum mechanics and quantum field theory where coherent states can also be considered. In the compact case we verify that the entanglement entropy expressions are consistent with T-duality.

arXiv:1407.7057Journal of High Energy PhysicsJan 1, 201538 citations

Left-Right Entanglement Entropy of Boundary States

Leopoldo A. Pando Zayas, O Zayas, Norma Quiroz +1 more

Aug 17, 201631 citations

Entanglement entropy for open bosonic strings on Dp-branes

Taejin Lee

We study the entanglement entropy for open bosonic strings on multiple Dp -branes by using the covariant open string field theory. Choosing one of the spatial coordinates which are tangential to the hyperplane on which Dp -branes are located, we divide the hyperplane into two halves. By using the string wavefunction in the Fock space representation, we evaluate the entanglement entropy. The entanglement entropy is found to be proportional to the area of ( p − 1 ) -dimensional boundary of the bipartite hyperplanes and divergent in the ultraviolet (UV) region as well as in the infrared (IR) region. However, the leading divergences are mainly due to tachyon contributions to the entanglement entropy, which may be absent in supersymmetric string theories . Apart from the divergences thanks to tachyons, the entanglement entropy for open bosonic strings on Dp -branes is finite for 2 ≤ p ≤ d critical − 2 and logarithmically divergent for p = 1 , d critical − 1 .We study the entanglement entropy for open bosonic strings on multiple Dp -branes by using the covariant open string field theory. Choosing one of the spatial coordinates which are tangential to the hyperplane on which Dp -branes are located, we divide the hyperplane into two halves. By using the string wavefunction in the Fock space representation, we evaluate the entanglement entropy. The entanglement entropy is found to be proportional to the area of ( p − 1 ) -dimensional boundary of the bipartite hyperplanes and divergent in the ultraviolet (UV) region as well as in the infrared (IR) region. However, the leading divergences are mainly due to tachyon contributions to the entanglement entropy, which may be absent in supersymmetric string theories . Apart from the divergences thanks to tachyons, the entanglement entropy for open bosonic strings on Dp -branes is finite for 2 ≤ p ≤ d critical − 2 and logarithmically divergent for p = 1 , d critical − 1 .

arXiv:1802.00169Physics Letters BJun 4, 20183 citations

LREE of a dressed Dp-brane with transverse motion in the partially compact spacetime

Hamidreza Daniali, Davoud Kamani

A bstract In the context of the type IIA/IIB superstring theories, we derive the left-right entanglement entropy (LREE) of a BPS D p -brane with transverse motion in the presence of a U(1) gauge potential and the Kalb-Ramond field in the partially compact spacetime T n ⊗ ℝ 1,9 − n . At first we employ the replica trick to compute the Rényi entropy and then we obtain the entanglement entropy. We examine the results for the special case, i.e. for the D6-brane. Besides, we investigate the thermodynamical entropy, associated with the LREE. This demonstrates that the LREE is precisely equivalent to its thermodynamic counterpart.A bstract In the context of the type IIA/IIB superstring theories, we derive the left-right entanglement entropy (LREE) of a BPS D p -brane with transverse motion in the presence of a U(1) gauge potential and the Kalb-Ramond field in the partially compact spacetime T n ⊗ ℝ 1,9 − n . At first we employ the replica trick to compute the Rényi entropy and then we obtain the entanglement entropy. We examine the results for the special case, i.e. for the D6-brane. Besides, we investigate the thermodynamical entropy, associated with the LREE. This demonstrates that the LREE is precisely equivalent to its thermodynamic counterpart.

arXiv:2410.09784Journal of High Energy PhysicsJan 15, 20250 citations

B_{\mu \nu }

Bμν . We derive the entanglement entropy via the Rényi entropy by applying the replica trick. Our calculations will be in the context of the bosonic string theory.