Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:hep-th/0301249 · International Journal of Modern Physics A

TFD Approach to Bosonic Strings and Dp-Branes

M. C. B. Abdalla, A. L. Gadelha, Ion V. Vancea

Published May 10, 2003• 24 citations
arXivHTMLPDF

Abstract

In this work we explain the construction of the thermal vacuum for the bosonic string, as well that of the thermal boundary state interpreted as a Dp-brane at finite temperature. In both case we calculate the respective entropy using the entropy operator of the Thermo Field Dynamics theory. We show that the contribution of the thermal string entropy is explicitly present in the Dp-brane entropy. Furthermore, we show that the Thermo Field approach is suitable to introduce temperature in boundary states.

DOI
10.1142/s0217751x03015556

Related papers

Bosonic String at Finite Temperature

de Souza, W. P.

The Thermo Field Dynamics formalism is presented. In particular, it is applied to the two-dimensional field theory that describes a open bosonic string. The value of entropy operator is computed in various Dirichlet and Neumann boundary states. The Thermal Bogoliubov transformations, the thermal vacuum and the thermal Fock space are computed explicitely for the case of SU(1,1) thermal algebra.

arXiv:hep-th/0208134•Aug 19, 2002•1 citation

Thermo Field Dynamics of strings with definite boundary conditions

Ion V. Vancea

In this paper we review the construction of the thermal bosonic string and $D$-brane in the framework of the Thermo Field Dynamics (TFD). We briefly recall the well-known light-cone quantization of the bosonic string in the conformal gauge in flat space-time. Then we give a bird's eye view of the fundamental concepts of the TFD. Also, we present the thermalization of the bosonic string and the construction of the thermal D-brane boundary state. Finally, we show the calculation of the entropy of the thermal open string states with all boundary conditions and the entropy of the thermal D-brane state.

arXiv:1508.05815•Aug 24, 2015•1 citation

SU(1,1) thermal group of bosonic strings andD-branes

M. C. B. Abdalla, A. L. Gadelha, Ion V. Vancea

All possible Bogoliubov operators that generate the thermal transformations in thermo field dynamics form an $\mathrm{SU}(1,1)$ group. We discuss this construction in the bosonic string theory. In particular, the transformation of the Fock space and string operators generated by the most general $\mathrm{SU}(1,1)$ unitary Bogoliubov transformation and the entropy of the corresponding thermal string are computed. Also, we construct the thermal D-brane generated by the $\mathrm{SU}(1,1)$ transformation in a constant Kalb-Ramond field and compute its entropy.

arXiv:hep-th/0203222•Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D. Particles and fields•Sep 19, 2002•33 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 .

arXiv:1802.00169•Physics Letters B•Jun 4, 2018•3 citations

General Unitary TFD Formulation for Superstrings

M. C. B. Abdalla, A. L. Gadelha, Daniel L. Nedel

A generalization of the Thermo Field Dynamics (TFD) for fermionic degrees of freedom is proposed. Such a generalization follows a previous one where the SU(1,1) thermal group was used to obtain the closed bosonic string at finite temperature. The SU(2) thermal group is introduced to construct a general thermal Bogoliubov transformation to get the type IIB superstring at finite temperature.

arXiv:hep-th/0412128•Contributed to•Dec 13, 2004•5 citations

String in AdS black hole: A thermo field dynamic approach

M. Botta Cantcheff, A. L. Gadelha, Dáfni F. Z. Marchioro +1 more

Based on Maldacena's description of an eternal anti--de Sitter (AdS) black hole, we reassess the thermo field dynamics (TFD) formalism in the context of the AdS/CFT correspondence. The model studied here involves the maximally extended AdS-Schwarschild solution and two (noninteracting) copies of the conformal field theory (CFT) associated to the global AdS spacetime, along with an extension of the string by imposing natural gluing conditions in the horizon. We show that the gluing conditions in the horizon define a string boundary state which is identified with the TFD thermal vacuum, globally defined in the Kruskal extension of the AdS black hole. We emphasize the connection of this picture with unitary $SU(1,1)$ TFD formulation, and we show that information about the bulk and the conformal boundary is present in the $SU(1,1)$ parameters. Using the unitary $SU(1,1)$ TFD formulation, a canonical prescription for calculating the world sheet real time thermal Green's function is made, and the entropy associated with the entanglement of the two CFT's is calculated.

arXiv:1205.3438•Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D. Particles and fields•Oct 22, 2012•9 citations
In this work we explain the construction of the thermal vacuum for the bosonic string, as well that of the thermal boundary state interpreted as a Dp-brane at finite temperature. In both case we calculate the respective entropy using the entropy operator of the Thermo Field Dynamics theory. We show that the contribution of the thermal string entropy is explicitly present in the Dp-brane entropy. Furthermore, we show that the Thermo Field approach is suitable to introduce temperature in boundary states.
In this paper we review the construction of the thermal bosonic string and DDD-brane in the framework of the Thermo Field Dynamics (TFD). We briefly recall the well-known light-cone quantization of the bosonic string in the conformal gauge in flat space-time. Then we give a bird's eye view of the fundamental concepts of the TFD. Also, we present the thermalization of the bosonic string and the construction of the thermal D-brane boundary state. Finally, we show the calculation of the entropy of the thermal open string states with all boundary conditions and the entropy of the thermal D-brane state.
All possible Bogoliubov operators that generate the thermal transformations in thermo field dynamics form an SU(1,1)\mathrm{SU}(1,1)SU(1,1) group. We discuss this construction in the bosonic string theory. In particular, the transformation of the Fock space and string operators generated by the most general SU(1,1)\mathrm{SU}(1,1)SU(1,1) unitary Bogoliubov transformation and the entropy of the corresponding thermal string are computed. Also, we construct the thermal D-brane generated by the SU(1,1)\mathrm{SU}(1,1)SU(1,1) transformation in a constant Kalb-Ramond field and compute its entropy.
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 .
Based on Maldacena's description of an eternal anti--de Sitter (AdS) black hole, we reassess the thermo field dynamics (TFD) formalism in the context of the AdS/CFT correspondence. The model studied here involves the maximally extended AdS-Schwarschild solution and two (noninteracting) copies of the conformal field theory (CFT) associated to the global AdS spacetime, along with an extension of the string by imposing natural gluing conditions in the horizon. We show that the gluing conditions in the horizon define a string boundary state which is identified with the TFD thermal vacuum, globally defined in the Kruskal extension of the AdS black hole. We emphasize the connection of this picture with unitary SU(1,1)SU(1,1)SU(1,1) TFD formulation, and we show that information about the bulk and the conformal boundary is present in the SU(1,1)SU(1,1)SU(1,1) parameters. Using the unitary SU(1,1)SU(1,1)SU(1,1) TFD formulation, a canonical prescription for calculating the world sheet real time thermal Green's function is made, and the entropy associated with the entanglement of the two CFT's is calculated.