Quantum computers are emerging technologies expected to become important tools for exploring various aspects of fundamental physics in the future. Therefore, we pose the question of whether quantum computers can help us to study the Page curve and the black hole information dynamics, which has been a key focus in fundamental physics. In this regard, we rigorously examine the qubit transport model, a toy qubit model of black hole evaporation on IBM’s superconducting quantum computers, to shed light on this question. Specifically, we implement the quantum simulation of the scrambling dynamics in black holes using an efficient random unitary circuit. Furthermore, we employ the swap-based many-body interference protocol and the randomized measurement protocol to measure the entanglement entropy of Hawking radiation qubits in this model. Finally, by incorporating quantum error mitigation techniques into our challenging implementation of entanglement entropy measurement protocols on the IBM quantum hardware, we accurately determine the Rényi entropy in the qubit transport model, thus showcasing the utility of quantum computers for future investigations of complex quantum systems.

Bangladesh

United States

Talal Ahmed Chowdhury

Kwangmin Yu

Muhammad Asaduzzaman

Raza Sabbir Sufian

Capturing the Page curve and entanglement dynamics of black holes in quantum computers

The present work delves into probing the importance of mutual information of relevant subsystems in obtaining the correct time-evolution of fine-grained entropy of Hawking radiation, as suggested by Page. This was done by considering a functional renormalization group improved or simply, quantum corrected Schwarzschild black solution which captures the flavour of an effective theory of quantum gravity. The mentioned black hole solution emerges from an asymptotically safe average effective action which describes a trajectory in momentum-space and satisfies a renormalization group equation. Furthermore, in the before Page time scenario, the behaviour of the mutual information between appropriate subsystems over time leads to the Hartman–Maldacena time. The observations made for the quantum corrected Schwarzschild black hole have been compared to the same made for the standard Schwarzschild black hole in order to draw some novel conclusions. Based upon our observations, we also propose a formula for computing fine-grained entropy of Hawking radiation for an eternal black hole, in presence of the island.

India

Ashis Saha

Anirban Chowdhury

Sunandan Gangopadhyay

Investigating the role of mutual information in the Page curve for a functional renormalization group improved Schwarzschild black hole

<p>This work employs the quantum extremal surface framework to compute the Page curve for black holes corrected by nonextensive entropy. The entropy of Hawking radiation increases linearly with time, leading to the persistence of the information paradox for nonextensive entropy-corrected black holes. At late time, we extremize the generalized entropy functional; incorporating contributions from both matter and the quantum extremal island, we establish that the entanglement entropy of Hawking radiation saturates to the nonextensive extension of the Bekenstein-Hawking entropy. Finally, we study the dependence of nonextensive parameters on the Page time.</p>

Ankit Anand

Dinesh Kumar

Aditya Singh

Effect of a nonextensive parameter on the Page curve

We compute the entanglement entropy of Hawking radiation in a bath attached to a deformed eternal AdS black hole. This black hole is dual to the two identical strongly coupled large- <math altimg='si1.svg'><msub><mrow><mi>N</mi></mrow><mrow><mi>c</mi></mrow></msub></math> thermal field theories, where each theory is backreacted (deformed) by the presence of a uniform static distribution of heavy fundamental quarks. In our observation we find that the entanglement entropy of Hawking radiation increases in a quadratic manner for an early time and linearly for the late time. The large time expression for the entanglement entropy of Hawking radiation is used to find the Page curve and Page time. After the Page time, the entanglement entropy saturates to a constant value due to the appearance of an island. We observe that introducing deformation (backreaction) delays the appearance of island and shifts the Page curve to a later time. Subsequently, the computation of the scrambling time reveals an increase with the backreaction parameter, suggesting a longer duration for information retrieval in the presence of deformation. Moreover, our analysis of the mutual information between the radiation subsystems shows that it vanishes at a critical time which increases with the deformation before the Page time. After the Page time, the appearance of island leads to the vanishing of mutual information between black hole subsystems and gives the time difference of the order of scrambling time.

South Korea

Parul Jain

Sanjay Pant

Taiwan

Himanshu Parihar

Effect of backreaction on island, Page curve and mutual information

We investigate the combined effect of rotation and finite chemical potential in the confinement/deconfinement transition of strongly interacting matter. The holographic description consists of a five-dimensional geometry that contains a black hole (BH) in the deconfined (plasma) phase. The geometry is equipped with some cut-off that introduces an infrared energy scale. We consider two possibilities: the so-called hard wall and soft wall AdS/QCD models. The transition between the plasma and hadronic phases is represented holographically as a Hawking-Page transition between geometries with and without a black hole. The gravitational dual of the rotating plasma at finite density is given by a Reissner-Nordström (RN) charged anti-de Sitter (AdS) BH with non-zero angular momentum. This analysis provides the critical temperature of deconfinement as a function of the quark chemical potential and the plasma rotational velocity. For the case of very low temperatures, the dependence of the critical values of the chemical potential for the transition to occur at <math altimg='si1.svg'><mi>T</mi><mo stretchy='false'>&#8594;</mo><mn>0</mn></math> on the rotation is found.

Brazil

Nelson R.F. Braga

Octavio C. Junqueira

Holographic QCD phase diagram for a rotating plasma in the Hawking-Page approach

We compute all planar two-loop six-point Feynman integrals entering scattering observables in massless gauge theories such as QCD. A central result of this paper is the formulation of the differential-equations method under the algebraic constraints stemming from four-dimensional kinematics, which in this case leaves only 8 independent scales. We show that these constraints imply that one must compute topologies with only up to 8 propagators, instead of the expected 9. This leads to the decoupling of entire classes of integrals that do not contribute to scattering amplitudes in four dimensional gauge theories. We construct a pure basis and derive their canonical differential equations, of which we discuss the numerical solution. This work marks an important step towards the calculation of massless 2 → 4 scattering processes at two loops.

Switzerland

not found

Samuel Abreu

Pier Monni

Belgium

Ben Page

Germany

Johann Usovitsch

Planar six-point Feynman integrals for four-dimensional gauge theories

We present compact two-loop QCD corrections in the leading-color approximation for the production of an electroweak vector boson, $\textit{V}$ = {$\textit{W}$ , $\textit{Z}$, $\textit{γ}$ }, in association with two light jets ($\textit{Vjj}$) at hadron colliders. Leptonic decays of the electroweak boson are included at the amplitude level. Working in the analytic-reconstruction approach, we develop two techniques to build compact partial-fraction forms for individual rational functions. One approach exploits their analytic structure. In the other, we iteratively construct subtraction terms that match the rational functions in singular limits. Moreover, we show how the singular behavior of the rational functions can be systematically used to find a more compact basis of the space that they span. We apply our techniques to the $\textit{Vjj}$ amplitudes, yielding a representation that is three orders of magnitude smaller than previous results. We then use these compact expressions to provide an efficient and stable C++ numerical implementation suitable for phenomenological applications.

Giuseppe Laurentis

Harald Ita

Vasily Sotnikov

Compact two-loop QCD corrections for $\textit{Vjj}$ production in proton collisions

We propose that the quantum states of black hole responsible for the Bekenstein-Hawking entropy are given by a thin shell of Bell particles located at the region just underneath the horizon. We argue that the configuration can be stabilized by a new kind of degeneracy pressure which is suggested by a noncommutative geometry in the interior of the black hole. Black hole singularity is avoided. We utilize the work of Parikh and Wilczek <cross-ref refid='br0010' id='crf0060'>[1]</cross-ref> to include the effect of tunneling on the Bell particles. We show that partially tunneled Bell particles give the Page curve of Hawking radiation, and the entirety of information initially stored in the black hole is returned to the outside via the Hawking radiation. In view of entropic force, the location of these Bell states is naturally related to the island and the quantum extremal surface.

Chong-Sun Chu

China

Rong-Xin Miao

Tunneling of Bell particles, page curve and black hole information

To explore the inverse problem tied to the Page curve phenomenon and island paradigm, we investigate the geometric conditions underpinning black hole evaporation, where information is preserved and islands manifest, giving rise to the characteristic Page curve. Focusing on a broad class of static spherical symmetry black hole metrics in asymptotically Minkowski or (anti-)de Sitter spacetimes, we derive a pivotal constraint, the second derivative of the blacken factor $ f^{\prime \prime}(r_h) \lt \frac{6 \kappa A^{\prime}(r_h)}{cG_N} $ for which the island exists, and reproduce the Page curve. Moreover, starting from the quantum focusing conjecture theory, we obtain another constraint on the blacken factor for which the theory can be satisfied: $f^{\prime \prime}(r_h) \lt \frac{6 \kappa^2 r_h A^{\prime}(r_h) {\rm e}^{2\kappa r_{\star}(b)} }{cG_N f(b)}$ . In particular, by studying these two constraints, we find common properties. Specifically, we reveal that a universal criterion, manifested in the negativity of the second derivative of $ f(r) $ , i.e., $ f^{\prime \prime} (r) \lt 0 $ , in proximity to the event horizon where $ r \sim r_h+ {\cal O} (G_N) $ , ensures the emergence of Page curves and follows the quantum focusing conjecture in a manner transcending specific theoretical models. Finally, we argue that the negativity of the second derivative of the blacken factor $ f(r) $ near the event horizon strongly indicates negative heat capacity, which implies that black holes with a negative heat capacity must have islands and satisfy the quantum focusing conjecture.

Ming-Hui Yu

Xian-Hui Ge

Geometric constraints via Page curves: insights from island rule and quantum focusing conjecture * Project partially supported by the National Science Foundation of China (12275166, 12311540141)

This paper delves into the Hawking-Page phase transitions of charged Anti-de Sitter (AdS) black holes within the context of four-dimensional Einstein-Gauss-Bonnet gravity are presented. Reentrant Hawking-Page phase transition, alongside triple points are introduced in spherically symmetric charged AdS black holes. The reentrant transition is characterized by two distinct Hawking-Page transitions, each associated with unique temperatures, while the triple points signify the simultaneous existence of small, massless, and large black holes. The hyperbolic Gauss-Bonnet charged AdS black hole solution is given, establishing that both charged and uncharged hyperbolically symmetric AdS black holes manifest the classical Hawking-Page phase transition properties. P-T phase diagram are constructed under dual symmetries, highlighting special points such as triple and critical points, and analyzing how variations in the Gauss-Bonnet constant and electric potential impact Hawking-Page phase transitions. The 4D Einstein-Gauss-Bonnet gravity theory, which serves as an effective four-dimensional reduction of the Gauss-Bonnet gravitational theory, bearing immense theoretical significance. According to the AdS/CFT correspondence theory, the conventional Hawking-Page phase transition finds interpretation as the confinement-deconfinement transition within gauge theories, while the reentrant Hawking-Page phase transition and triple points can also be interpreted as the phase transition and triple points in the QCD phase diagram. These advancements hold promise for deepening insights into black hole thermodynamics in the framework of quantum gravity.

Xiao-yan Hu

Yuan-zhang Cui

Wei Xu

Hawking-Page transition in 4D Einstein-Gauss-Bonnet gravity