scholarly journals Does the HM mechanism work in string theory?

2013 ◽  
Vol 91 (1) ◽  
pp. 75-80
Author(s):  
Alireza Sepehri ◽  
Somayyeh Shoorvazi ◽  
Mohammad Ebrahim Zomorrodian

The correspondence principle offers a unique opportunity to test the Horowitz and Maldacena mechanism at the correspondence point “the centre of mass energies around (Ms/(gs)2)”. First by using the Horowitz and Maldacena proposal, the black hole final state for closed strings is studied and the entropy of these states is calculated. Then, to consider the closed string states, a copy of the original Hilbert space is constructed with a set of creation–annihilation operators that have the same commutation properties as the original ones. The total Hilbert space is the tensor product of the two spaces Hright ⊗ Hleft, where in this case Hleft/right denote the physical quantum state space of the closed string. It is shown that closed string states can be represented by a maximally entangled two-mode squeezed state of the left and right spaces of closed string. Also, the entropy for these string states is calculated. It is found that black hole entropy matches the closed string entropy at transition point. This means that our result is consistent with correspondence principle and thus HM mechanism in string theory works. Consequently the unitarity of the black hole in string theory can be reconciled. However Gottesman and Preskill point out that, in this scenario, departures from unitarity can arise due to interactions between the collapsing body and the infalling Hawking radiation inside the event horizon and information can be lost. By extending the Gottesman and Preskill method to string theory, the amount of information transformation from the matter to the state of outgoing Hagedorn radiation for closed strings is obtained. It is observed that information is lost for closed strings.

10.33540/165 ◽  
2020 ◽  
Author(s):  
◽  
Herbert het Lam

Author(s):  
Jeffrey A. Harvey

Ramanujan influenced many areas of mathematics, but his work on q -series, on the growth of coefficients of modular forms and on mock modular forms stands out for its depth and breadth of applications. I will give a brief overview of how this part of Ramanujan's work has influenced physics with an emphasis on applications to string theory, counting of black hole states and moonshine. This paper contains the material from my presentation at the meeting celebrating the centenary of Ramanujan's election as FRS and adds some additional material on black hole entropy and the AdS/CFT correspondence. This article is part of a discussion meeting issue ‘Srinivasa Ramanujan: in celebration of the centenary of his election as FRS’.


2006 ◽  
Vol 15 (10) ◽  
pp. 1561-1572 ◽  
Author(s):  
ATISH DABHOLKAR

In this talk I summarize some recent progress in string theory in understanding the entropy of a class of black holes including corrections to the Bekenstein–Hawking formula. The quantum corrected entropy is in precise numerical agreement with the logarithm of the number of microstates once quantum corrections are correctly taken into account.


2021 ◽  
Vol 2021 (10) ◽  
Author(s):  
William Donnelly ◽  
Yikun Jiang ◽  
Manki Kim ◽  
Gabriel Wong

Abstract Progress in identifying the bulk microstate interpretation of the Ryu-Takayanagi formula requires understanding how to define entanglement entropy in the bulk closed string theory. Unfortunately, entanglement and Hilbert space factorization remains poorly understood in string theory. As a toy model for AdS/CFT, we study the entanglement entropy of closed strings in the topological A-model in the context of Gopakumar-Vafa duality. We will present our results in two separate papers. In this work, we consider the bulk closed string theory on the resolved conifold and give a self-consistent factorization of the closed string Hilbert space using extended TQFT methods. We incorporate our factorization map into a Frobenius algebra describing the fusion and splitting of Calabi-Yau manifolds, and find string edge modes transforming under a q-deformed surface symmetry group. We define a string theory analogue of the Hartle-Hawking state and give a canonical calculation of its entanglement entropy from the reduced density matrix. Our result matches with the geometrical replica trick calculation on the resolved conifold, as well as a dual Chern-Simons theory calculation which will appear in our next paper [1]. We find a realization of the Susskind-Uglum proposal identifying the entanglement entropy of closed strings with the thermal entropy of open strings ending on entanglement branes. We also comment on the BPS microstate counting of the entanglement entropy. Finally we relate the nonlocal aspects of our factorization map to analogous phenomenon recently found in JT gravity.


1994 ◽  
Vol 50 (8) ◽  
pp. 5225-5231 ◽  
Author(s):  
Michael McGuigan

2006 ◽  
Vol 2006 (01) ◽  
pp. 098-098 ◽  
Author(s):  
Ram Brustein ◽  
Martin B Einhorn ◽  
Amos Yarom

2020 ◽  
Vol 2020 (8) ◽  
Author(s):  
Maxim Fitkevich ◽  
Dmitry Levkov ◽  
Sergey Sibiryakov

Abstract We use complex semiclassical method to compute scattering amplitudes of a point particle in dilaton gravity with a boundary. This model has nonzero minimal black hole mass Mcr. We find that at energies below Mcr the particle trivially scatters off the boundary with unit probability. At higher energies the scattering amplitude is exponentially suppressed. The corresponding semiclassical solution is interpreted as formation of an intermediate black hole decaying into the final-state particle. Relating the suppression of the scattering probability to the number of the intermediate black hole states, we find an expression for the black hole entropy consistent with thermodynamics. In addition, we fix the constant part of the entropy which is left free by the thermodynamic arguments. We rederive this result by modifying the standard Euclidean entropy calculation.


2000 ◽  
Vol 15 (01) ◽  
pp. 1-44 ◽  
Author(s):  
E. T. AKHMEDOV

In this review we try to give a pedagogical introduction to the recent progress in the resolution of old problems of black hole thermodynamics within superstring theory. We start with a brief description of classical black hole dynamics. Then, follow with the consideration of general properties of supersymmetric black holes. We conclude with the review of the statistical explanation of the black hole entropy and string theory description of the black hole evaporation.


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