掲載種別：研究論文（学術雑誌）   出版者・発行元：Springer Science and Business Media LLC  

Abstract

It has long been thought that a highly excited string can be regarded as a black hole: the correspondence principle between strings and a black hole, while recent studies found that black holes are characterized by chaos. This suggests that highly excited strings are the source of the black hole chaoticity. We study the chaoticity of a string amplitude where a tachyon is scattered by a highly excited string. Our strategy to extract the chaos in the amplitude is a generalization of the transient chaos analysis for classical scattering. We look for the fractal structure in the plots of incoming/outgoing scattering angles, where the outgoing angle is defined as the maximum pole of the amplitude. Within our strategy, we could not identify any fractal structure in the scattering data. We also discuss other possible setups and strategies to extract the chaos, hoping that our present work serves as a step toward the formulation of chaos in string scattering amplitudes.

DOI： 10.1007/jhep11(2022)147

Open Access

その他リンク： https://link.springer.com/article/10.1007/JHEP11(2022)147/fulltext.html

掲載種別：研究論文（学術雑誌）   出版者・発行元：Springer Science and Business Media LLC  

Abstract

Recently, it was proposed that there must be either large violation of the additivity conjecture or a set of disentangled states of the black hole in the AdS/CFT correspondence. In this paper, we study the additivity conjecture for quantum states of fields around the Schwarzschild black hole. In the eternal Schwarzschild spacetime, the entanglement entropy of the Hawking radiation is calculated assuming that the vacuum state is the Hartle-Hawking vacuum. In the additivity conjecture, we need to consider the state which gives minimal output entropy of a quantum channel. The Hartle-Hawking vacuum state does not give the minimal output entropy which is consistent with the additivity conjecture. We study the entanglement entropy in other static vacua and show that it is consistent with the additivity conjecture.

DOI： 10.1007/jhep06(2022)109

Open Access

その他リンク： https://link.springer.com/article/10.1007/JHEP06(2022)109/fulltext.html

掲載種別：研究論文（学術雑誌）   出版者・発行元：American Physical Society (APS)  

DOI： 10.1103/physrevd.104.064005

その他リンク： http://harvest.aps.org/v2/journals/articles/10.1103/PhysRevD.104.064005/fulltext

掲載種別：研究論文（学術雑誌）   出版者・発行元：American Physical Society (APS)  

DOI： 10.1103/physrevd.104.026006

Open Access

その他リンク： http://harvest.aps.org/v2/journals/articles/10.1103/PhysRevD.104.026006/fulltext

掲載種別：研究論文（学術雑誌）   出版者・発行元：Springer Science and Business Media LLC  

Abstract

Recently it was proposed that the entanglement entropy of the Hawking radiation contains the information of a region including the interior of the event horizon, which is called “island.” In studies of the entanglement entropy of the Hawking radiation, the total system in the black hole geometry is separated into the Hawking radiation and black hole. In this paper, we study the entanglement entropy of the black hole in the asymptotically flat Schwarzschild spacetime. Consistency with the island rule for the Hawking radiation implies that the information of the black hole is located in a different region than the island. We found an instability of the island in the calculation of the entanglement entropy of the region outside a surface near the horizon. This implies that the region contains all the information of the total system and the information of the black hole is localized on the surface. Thus the surface would be interpreted as the stretched horizon. This structure also resembles black holes in the AdS spacetime with an auxiliary flat spacetime, where the information of the black hole is localized at the interface between the AdS spacetime and the flat spacetime.

DOI： 10.1007/jhep07(2021)051

Open Access

その他リンク： https://link.springer.com/article/10.1007/JHEP07(2021)051/fulltext.html

掲載種別：研究論文（学術雑誌）   出版者・発行元：American Physical Society (APS)  

DOI： 10.1103/physrevb.102.195128

その他リンク： http://harvest.aps.org/v2/journals/articles/10.1103/PhysRevB.102.195128/fulltext

掲載種別：研究論文（学術雑誌）   出版者・発行元：American Physical Society (APS)  

DOI： 10.1103/physrevd.102.024090

Open Access

その他リンク： http://harvest.aps.org/v2/journals/articles/10.1103/PhysRevD.102.024090/fulltext

掲載種別：研究論文（学術雑誌）   出版者・発行元：Springer Science and Business Media LLC  

DOI： 10.1007/jhep06(2020)085

Open Access

掲載種別：研究論文（学術雑誌）   出版者・発行元：American Physical Society (APS)  

DOI： 10.1103/physrevb.101.245138

その他リンク： http://harvest.aps.org/v2/journals/articles/10.1103/PhysRevB.101.245138/fulltext

掲載種別：研究論文（学術雑誌）   出版者・発行元：IOP Publishing  

DOI： 10.1088/1361-6382/ab5c94

その他リンク： https://iopscience.iop.org/article/10.1088/1361-6382/ab5c94/pdf

掲載種別：研究論文（学術雑誌）   出版者・発行元：Springer Science and Business Media LLC  

Abstract

A new method to study nuclear physics via holographic QCD is proposed. Multiple baryons in the Sakai-Sugimoto background are described by a matrix model which is a low energy effective theory of D-branes of the baryon vertices. We study the quantum mechanics of the matrix model and calculate the eigenstates of the Hamiltonian. The obtained states are found to coincide with known nuclear and baryonic states, and have appropriate statistics and charges. Calculated spectra of the baryon/nucleus for small baryon numbers show good agreement with experimental data. For hyperons, the Gell-Mann–Okubo formula is approximately derived. Baryon resonances up to spin 5/2 and isospin 5/2 and dibaryon spectra are obtained and compared with experimental data. The model partially explains even the magic numbers of light nuclei, N = 2, 8 and 20.

DOI： 10.1007/jhep12(2019)001

Open Access

arXiv

その他リンク： https://link.springer.com/article/10.1007/JHEP12(2019)001/fulltext.html

掲載種別：研究論文（学術雑誌）   出版者・発行元：Springer Science and Business Media LLC  

Abstract

Assuming spherical symmetry and the semi-classical Einstein equation, we prove that, for the observers on top of the trapping horizon, the vacuum energy-momentum tensor is always that of an ingoing negative energy flux at the speed of light with a universal energy density ℰ ≃ − 1/(2κa ²), (where a is the areal radius of the trapping horizon), which is responsible for the decrease in the black hole’s mass over time. This result is independent of the composition of the collapsing matter and the details of the vacuum energy-momentum tensor. The physics behind the universality of this quantity ℰ and its surprisingly large magnitude will be discussed.

DOI： 10.1007/jhep06(2019)057

Open Access

その他リンク： https://link.springer.com/article/10.1007/JHEP06(2019)057/fulltext.html

記述言語：英語   掲載種別：研究論文（学術雑誌）  

For a black hole of Schwarzschild radius $a$, we argue that the back-reaction of the vacuum energy-momentum tensor is in general important at the apparent horizon when the time scale of a process is larger than order $a$. In particular, in a double-shell model, we show that the ignorance of the back-reaction leads to a divergence in the outgoing vacuum energy flux. The main result of this paper is that, once the back-reaction is included, the vacuum energy density for observers on top of the trapping horizon in vacuum is given by ${\cal E} \simeq -1/2\ell_p^2 a^2$, which is of the same order of magnitude as the classical matter but opposite in sign. Remarkably, this formula is independent of both the details about the collapsing matter and the vacuum energy-momentum tensor.

掲載種別：研究論文（学術雑誌）   出版者・発行元：Springer Science and Business Media LLC  

Abstract

Static, spherically symmetric black hole solutions to the semi-classical Einstein equation are studied, including the effect of the quantum energy-momentum tensor for conformal matters with 4D Weyl anomaly. Through both perturbative and non-perturbative methods, we show that the quantum effect can play a crucial role in shaping the nearhorizon geometry, and that the existence of the horizon requires fine-tuning.

DOI： 10.1007/jhep11(2018)056

Open Access

その他リンク： https://link.springer.com/article/10.1007/JHEP11(2018)056/fulltext.html

掲載種別：研究論文（学術雑誌）   出版者・発行元：Springer Science and Business Media LLC  

Abstract

The near-horizon geometry of evaporation black holes is determined according to the semi-classical Einstein equation. We consider spherically symmetric configurations in which the collapsing star has already collapsed below the Schwarzschild radius. The back-reaction of the vacuum energy-momentum, including Hawking radiation, is taken into account. The vacuum energy-momentum plays a crucial role in a small neighborhood of the apparent horizon, as it appears at the leading order in the semi-classical Einstein equation. Our study is focused on the time-dependent geometry in this region.

DOI： 10.1007/jhep07(2018)047

Open Access

その他リンク： https://link.springer.com/article/10.1007/JHEP07(2018)047/fulltext.html

掲載種別：研究論文（学術雑誌）   出版者・発行元：Springer Science and Business Media LLC  

Abstract

With the back reaction of the vacuum energy-momentum tensor consistently taken into account, we study static spherically symmetric black-hole-like solutions to the semi-classical Einstein equation. The vacuum energy is assumed to be given by that of 2-dimensional massless scalar fields, as a widely used model in the literature for black holes. The solutions have no horizon. Instead, there is a local minimum in the radius. We consider thin shells as well as incompressible fluid as the matter content of the black-hole-like geometry. The geometry has several interesting features due to the back reaction of vacuum energy. In particular, Buchdahl’s inequality can be violated without divergence in pressure, even if the surface is below the Schwarzschild radius. At the same time, the surface of the star can not be far below the Schwarzschild radius for a density not much higher than the Planck scale, and the proper distance from its surface to the origin can be very short even for very large Schwarzschild radius. The results also imply that, contrary to the folklore, in principle the Boulware vacuum can be physical for black holes.

DOI： 10.1007/jhep03(2018)096

Open Access

その他リンク： https://link.springer.com/article/10.1007/JHEP03(2018)096/fulltext.html

記述言語：英語   掲載種別：研究論文（学術雑誌）  

We study spherically symmetric static solutions to the semi-classical Einstein equation sourced by the vacuum energy of quantum fields in the curved space-time of the same solution. We found solutions that are small deformations of the Schwarzschild metric for distant observers, but without horizon. Instead of being a robust feature of objects with high densities, the horizon is sensitive to the energy-momentum tensor in the near-horizon region.

DOI： 10.1088/1361-6382/aaac8f

掲載種別：研究論文（学術雑誌）   出版者・発行元：Springer Science and Business Media LLC  

DOI： 10.1007/jhep03(2017)041

Open Access

Web of Science

掲載種別：研究論文（学術雑誌）   出版者・発行元：Springer Science and Business Media LLC  

DOI： 10.1007/jhep12(2015)076

Open Access

Web of Science

その他リンク： http://link.springer.com/content/pdf/10.1007/JHEP12(2015)076.pdf

掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier BV  

DOI： 10.1016/j.nuclphysb.2015.08.018

Open Access

Web of Science

掲載種別：研究論文（学術雑誌）   出版者・発行元：Springer Science and Business Media LLC  

DOI： 10.1007/jhep05(2014)008

Open Access

Web of Science

その他リンク： http://link.springer.com/content/pdf/10.1007/JHEP05(2014)008.pdf

掲載種別：研究論文（学術雑誌）   出版者・発行元：American Physical Society (APS)  

DOI： 10.1103/physrevd.89.046005

Web of Science

その他リンク： http://harvest.aps.org/v2/journals/articles/10.1103/PhysRevD.89.046005/fulltext

掲載種別：研究論文（学術雑誌）   出版者・発行元：American Physical Society (APS)  

DOI： 10.1103/physrevd.88.026020

Web of Science

その他リンク： http://harvest.aps.org/v2/journals/articles/10.1103/PhysRevD.88.026020/fulltext

掲載種別：研究論文（学術雑誌）   出版者・発行元：World Scientific Pub Co Pte Lt  

We construct a self-consistent model which describes a black hole from formation to evaporation including the backreaction from the Hawking radiation. In the case where a null shell collapses, at the beginning the evaporation occurs, but it stops eventually, and a horizon and singularity appear. On the other hand, in the generic collapse process of a continuously distributed null matter, the black hole evaporates completely without forming a macroscopically large horizon nor singularity. We also find a stationary solution in the heat bath, which can be regarded as a normal thermodynamic object.

DOI： 10.1142/s0217751x13500504

Web of Science

掲載種別：研究論文（学術雑誌）   出版者・発行元：Oxford University Press (OUP)  

DOI： 10.1093/ptep/pts069

Web of Science

DOI： 10.1142/S2010194513009513

掲載種別：研究論文（学術雑誌）   出版者・発行元：American Physical Society (APS)  

DOI： 10.1103/physrevd.86.074510

Web of Science

その他リンク： http://link.aps.org/article/10.1103/PhysRevD.86.074510

掲載種別：研究論文（学術雑誌）   出版者・発行元：Springer Science and Business Media LLC  

DOI： 10.1007/jhep07(2012)050

Web of Science

その他リンク： http://link.springer.com/article/10.1007/JHEP07(2012)050/fulltext.html

掲載種別：研究論文（学術雑誌）   出版者・発行元：Springer Science and Business Media LLC  

DOI： 10.1007/jhep01(2012)130

Web of Science

その他リンク： http://link.springer.com/article/10.1007/JHEP01(2012)130/fulltext.html

記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：Proceedings of Science (PoS)  

Finite-density QCD is difficult to study numerically because of the sign problem. We prove that, in a certain region of the phase diagram, the phase quenched approximation is exact to O(Nf =Nc). It is true for any physical observables. We also consider the implications for the lattice simulations and find a quantitative evidence for the validity of the phase quenching from existing lattice QCD results at Nc = 3. Our results show that the phase-quench approximation is rather good already at Nc = 3, and the 1=Nc correction can be incorporated by the phase reweighting method without suffering from the overlap problem. We also show the same equivalence in effective models and holographic models.

DOI： 10.22323/1.164.0072

Open Access

Scopus

掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier BV  

DOI： 10.1016/j.nuclphysb.2010.10.020

Web of Science

掲載種別：研究論文（学術雑誌）   出版者・発行元：Springer Science and Business Media LLC  

DOI： 10.1007/jhep12(2010)073

Web of Science

その他リンク： http://link.springer.com/article/10.1007/JHEP12(2010)073/fulltext.html

掲載種別：研究論文（学術雑誌）   出版者・発行元：Springer Science and Business Media LLC  

DOI： 10.1007/jhep05(2010)038

Web of Science

その他リンク： http://link.springer.com/article/10.1007/JHEP05(2010)038/fulltext.html

掲載種別：研究論文（学術雑誌）   出版者・発行元：Springer Science and Business Media LLC  

DOI： 10.1007/jhep04(2010)071

Web of Science

その他リンク： http://link.springer.com/article/10.1007/JHEP04(2010)071/fulltext.html

掲載種別：研究論文（学術雑誌）   出版者・発行元：IOP Publishing  

DOI： 10.1209/0295-5075/89/60001

Web of Science

掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier BV  

DOI： 10.1016/j.nuclphysb.2009.09.025

Web of Science

掲載種別：研究論文（学術雑誌）   出版者・発行元：American Physical Society (APS)  

DOI： 10.1103/physrevd.80.125001

Web of Science

その他リンク： http://harvest.aps.org/v2/journals/articles/10.1103/PhysRevD.80.125001/fulltext

掲載種別：研究論文（学術雑誌）   出版者・発行元：Springer Science and Business Media LLC  

DOI： 10.1088/1126-6708/2009/11/087

Web of Science

掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier BV  

DOI： 10.1016/j.nuclphysb.2009.02.026

Open Access

Web of Science

掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier BV  

DOI： 10.1016/j.physletb.2009.07.069

Open Access

Web of Science

掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier BV  

DOI： 10.1016/j.nuclphysb.2009.03.012

Web of Science

掲載種別：研究論文（学術雑誌）   出版者・発行元：Oxford University Press (OUP)  

DOI： 10.1143/ptp.120.833

Web of Science

掲載種別：研究論文（学術雑誌）   出版者・発行元：Springer Science and Business Media LLC  

DOI： 10.1088/1126-6708/2008/10/009

Web of Science

掲載種別：研究論文（学術雑誌）   出版者・発行元：Springer Science and Business Media LLC  

DOI： 10.1088/1126-6708/2008/06/051

Web of Science

掲載種別：研究論文（学術雑誌）   出版者・発行元：Springer Science and Business Media LLC  

DOI： 10.1088/1126-6708/2006/09/075

Web of Science

掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier BV  

DOI： 10.1016/j.nuclphysb.2006.02.006

Web of Science

掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier BV  

DOI： 10.1016/j.nuclphysb.2005.01.002

Web of Science

掲載種別：研究論文（学術雑誌）   出版者・発行元：Oxford University Press (OUP)  

DOI： 10.1143/ptp.112.131

Web of Science

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