BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//CERN//INDICO//EN
BEGIN:VEVENT
SUMMARY:Characteristic initial value problem and formation of black hole
DTSTART;VALUE=DATE-TIME:20261109T023000Z
DTEND;VALUE=DATE-TIME:20261109T030000Z
DTSTAMP;VALUE=DATE-TIME:20261023T102254Z
UID:indico-contribution-649-3066@indico.itp.ac.cn
DESCRIPTION:Speakers: Xiaoning Wu (Institute of Mathematics\, Academy of M
 athematics and Systems Science)\nhttps://indico.itp.ac.cn/event/417/contri
 butions/3066/
LOCATION:
URL:https://indico.itp.ac.cn/event/417/contributions/3066/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Regular ultracompact objects as polymerized vacuum solutions
DTSTART;VALUE=DATE-TIME:20261107T083000Z
DTEND;VALUE=DATE-TIME:20261107T090000Z
DTSTAMP;VALUE=DATE-TIME:20261023T102254Z
UID:indico-contribution-649-3065@indico.itp.ac.cn
DESCRIPTION:Speakers: Ioannis Soranidis (Westlake University)\nhttps://ind
 ico.itp.ac.cn/event/417/contributions/3065/
LOCATION:
URL:https://indico.itp.ac.cn/event/417/contributions/3065/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Nash Equilibrium from Quantum-Field Entanglement
DTSTART;VALUE=DATE-TIME:20261108T070000Z
DTEND;VALUE=DATE-TIME:20261108T073000Z
DTSTAMP;VALUE=DATE-TIME:20261023T102254Z
UID:indico-contribution-649-2946@indico.itp.ac.cn
DESCRIPTION:Speakers: Hao Xu (Yangzhou University)\nEntanglement harvestin
 g transfers quantum field correlations to localized probes\, yet whether t
 hese correlations can alter stable strategic behavior has remained unclear
 . We formulate a quantum-input game in which two Unruh–DeWitt detectors 
 harvest vacuum entanglement from a free massless scalar field in $(3+1)$-d
 imensional Minkowski spacetime. A referee converts this state into payoffs
  using independent question qubits and phase-calibrated local Bell measure
 ments. To leading perturbative order\, the mean reward is proportional to 
 the signed entanglement margin $\\sqrt{\\mathcal H^2+\\mathcal Q^2}-\\math
 cal P$\, where $\\mathcal H$ is the Hadamard correlation contribution\, $\
 \mathcal Q$ is the Pauli--Jordan causal contribution\, and $\\mathcal P$ i
 s the local excitation noise. Away from payoff degeneracies\, allowing eac
 h player to exit or to choose an early or late interaction yields $1+2n_+$
  trembling-hand perfect equilibria\, where $n_+$ counts the positive-rewar
 d timing equilibria. For one fixed protocol\, five analytically certified 
 settings realize the sequence $7\\to3\\to1\\to7\\to1$. They represent the 
 spacelike region\, the first commutator lobe\, central carrier cancellatio
 n\, the second lobe\, and the post-wavefront Huygens regime. Thus\, within
  this fixed quantum-input verification protocol\, distinct field-correlati
 on regimes generate different stable strategic structures.\n\nhttps://indi
 co.itp.ac.cn/event/417/contributions/2946/
LOCATION:
URL:https://indico.itp.ac.cn/event/417/contributions/2946/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Thermodynamics of Kerr-Bertotti-Robinson black hole
DTSTART;VALUE=DATE-TIME:20261109T033000Z
DTEND;VALUE=DATE-TIME:20261109T040000Z
DTSTAMP;VALUE=DATE-TIME:20261023T102254Z
UID:indico-contribution-649-2983@indico.itp.ac.cn
DESCRIPTION:Speakers: Li Hu (Ningbo University)\nhttps://indico.itp.ac.cn/
 event/417/contributions/2983/
LOCATION:
URL:https://indico.itp.ac.cn/event/417/contributions/2983/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Thermodynamics and chaotic orbits for semiclassical black hole wit
 h quantum anomaly correction
DTSTART;VALUE=DATE-TIME:20261109T030000Z
DTEND;VALUE=DATE-TIME:20261109T033000Z
DTSTAMP;VALUE=DATE-TIME:20261023T102254Z
UID:indico-contribution-649-2961@indico.itp.ac.cn
DESCRIPTION:Speakers: Yu-Sen An (Nanjing University of Aeronautics and Ast
 ronautics)\nBlack hole is an interesting physical object which is both a t
 hermodynamical system and nest of chaos. In this talk\, I will firstly int
 roduce the conformal anomaly corrections on the black hole geometry in 4d 
 spherical symmetric spacetime. After introducing the black hole solution\,
  I will discuss the thermodynamics and chaotic properties of this black ho
 le. We investigate the phase transition and critical phenomena of this ano
 maly corrected black hole and discover that anomaly can trigger the violat
 ion of Rushbrook scaling law at the critical point. This provides the firs
 t example of such scaling law violation in four dimensional spacetime. Mor
 eover\, we study the chaotic particle orbits around this black hole soluti
 on\, we find that anomaly can enhance the chaotic features of the black ho
 le which can also leave an imprint on the gravitational wave signals of th
 e EMRI systems.\n\nhttps://indico.itp.ac.cn/event/417/contributions/2961/
LOCATION:
URL:https://indico.itp.ac.cn/event/417/contributions/2961/
END:VEVENT
BEGIN:VEVENT
SUMMARY:On the absence of inner horizons for anisotropic black holes
DTSTART;VALUE=DATE-TIME:20261109T013000Z
DTEND;VALUE=DATE-TIME:20261109T020000Z
DTSTAMP;VALUE=DATE-TIME:20261023T102254Z
UID:indico-contribution-649-2951@indico.itp.ac.cn
DESCRIPTION:Speakers: Yuxuan Peng ()\nWe establish a general no-inner hori
 zon theorem for a wide class of static anisotropic black holes in Einstein
  gravity. As an application\, we demonstrate that a large variety of black
  holes which possess homogeneous but anisotropic three-dimensional horizon
 s can not have inner horizons. Our theorem is consistent with some previou
 sly known results\, implying an underlying mechanism that certain kinds of
  spatial anisotropy can remove inner horizons. Consequently\, anisotropic 
 black holes generically develop spacelike singularities in their interiors
 \, offering new insight into the interplay between anisotropy\, strong cos
 mic censorship\, and black hole interior structures.\n    早期研究表
 明，黑洞内视界是动力学不稳定的，符合强宇宙监督假
 设。近年来的研究表明，非平庸的物质毛发会破坏黑洞
 的内视界；而报告人近期发现，各向异性标度行为也能
 破坏内视界。这类各向异性黑洞被广泛应用在全息对偶
 中。本报告将介绍相应的无内视界定理，以及一类具有Bi
 anchi型视界的5维各向异性黑洞的内部结构的初步研究结
 果。\n\nhttps://indico.itp.ac.cn/event/417/contributions/2951/
LOCATION:
URL:https://indico.itp.ac.cn/event/417/contributions/2951/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Quasinormal Modes Decode Kasner Scaling inside Black Holes
DTSTART;VALUE=DATE-TIME:20261109T010000Z
DTEND;VALUE=DATE-TIME:20261109T013000Z
DTSTAMP;VALUE=DATE-TIME:20261023T102254Z
UID:indico-contribution-649-2987@indico.itp.ac.cn
DESCRIPTION:Speakers: Zi-Qing Xiao (ICTP-AP)\nCan the geometry hidden behi
 nd a black hole's event horizon be reconstructed from its exterior quasino
 rmal-mode spectrum? In this talk\, I will explore how high-overtone quasin
 ormal modes encode information about black hole interiors. We show that di
 stinct power-law corrections to the spectrum\, obtained through angular-mo
 mentum and scalar-mass responses\, allow the temporal and angular Kasner e
 xponents to be extracted separately\, without imposing the Kasner constrai
 nts. Using analytic monodromy methods and numerical calculations\, we demo
 nstrate this reconstruction in asymptotically flat black holes. In particu
 lar\, we establish a four-dimensional Schwarzschild benchmark\, where the 
 predicted scaling behavior is confirmed numerically\, and show that gravit
 ational perturbations exhibit the same singularity-sensitive asymptotic st
 ructure. We further investigate dilatonic black holes\, demonstrating that
  the reconstructed exponents track changes in the interior geometry. Compl
 ementary higher-dimensional and asymptotically AdS examples provide additi
 onal tests of the underlying mechanism. Our results establish a quantitati
 ve connection between exterior quasinormal-mode spectra and black hole int
 erior geometry\, opening a theoretical route toward probing otherwise inac
 cessible regions of spacetime.\n\nhttps://indico.itp.ac.cn/event/417/contr
 ibutions/2987/
LOCATION:
URL:https://indico.itp.ac.cn/event/417/contributions/2987/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Bianchi IX dynamics with a phantom field - a new type of BKL oscil
 lations
DTSTART;VALUE=DATE-TIME:20261109T003000Z
DTEND;VALUE=DATE-TIME:20261109T010000Z
DTSTAMP;VALUE=DATE-TIME:20261023T102254Z
UID:indico-contribution-649-2977@indico.itp.ac.cn
DESCRIPTION:Speakers: Alexey Toporensky (Sternberg Astronomical Institute)
 \nWe consider Bianchi IX dynamics of a Universe filled with a massless pha
 ntom field. Such an exotic matter source enables regimes impossible in vac
 uum or with a standard scalar field. In particular\, two Kasner indices of
  BKL oscillations can be simultaneously negative\, and the absolute value 
 of a negative index can be large. We describe the consequences of these fe
 atures and explain the nature of volume oscillations recently discovered  
 in such a system by numerical methods.\n\nhttps://indico.itp.ac.cn/event/4
 17/contributions/2977/
LOCATION:
URL:https://indico.itp.ac.cn/event/417/contributions/2977/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Quantum Gravity Corrections: From Background Dynamics to Cosmologi
 cal Perturbations
DTSTART;VALUE=DATE-TIME:20261108T093000Z
DTEND;VALUE=DATE-TIME:20261108T100000Z
DTSTAMP;VALUE=DATE-TIME:20261023T102254Z
UID:indico-contribution-649-2938@indico.itp.ac.cn
DESCRIPTION:Speakers: Hongguang Liu (Westlake University)\nQuantum-gravity
  models often provide effective background dynamics\, while cosmological o
 bservables depend on the dynamics of inhomogeneous perturbations. I will d
 iscuss a Hamiltonian framework for bridging this gap. Requiring consistent
  local evolution strongly constrains how a modified homogeneous or symmetr
 ic dynamics can be completed into a spatial theory. The resulting Hamilton
 ian determines not only the cosmological background but also its scalar an
 d tensor response.\nI will discuss how relational scale setting and non-pe
 rturbative renormalization can provide quantum input for this effective dy
 namics\, and how the same Hamiltonian framework connects it to cosmologica
 l perturbations and correlation functions.\n\nhttps://indico.itp.ac.cn/eve
 nt/417/contributions/2938/
LOCATION:
URL:https://indico.itp.ac.cn/event/417/contributions/2938/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Can higher derivatives resolve the black-hole singularity?
DTSTART;VALUE=DATE-TIME:20261108T090000Z
DTEND;VALUE=DATE-TIME:20261108T093000Z
DTSTAMP;VALUE=DATE-TIME:20261023T102254Z
UID:indico-contribution-649-2942@indico.itp.ac.cn
DESCRIPTION:Speakers: Breno Loureiro Giacchini (Charles University)\nHighe
 r-derivative and nonlocal gravity models arise in various approaches to qu
 antum gravity\, either as candidates for renormalizable theories of gravit
 y or as effective low-energy descriptions. In this talk\, we present sever
 al recent results on classical solutions in higher-derivative gravity\, fo
 cusing on the possibility of resolving the black-hole singularity present 
 in solutions of general relativity and quadratic gravity. We discuss the f
 irst local classification of static\, spherically symmetric exact solution
 s in generic six-derivative gravity and in a quasi-local extension of Eins
 tein-Weyl gravity. Although only regular cores are found in both cases\, w
 e argue that more complicated singular solutions might still exist and dis
 cuss the possibility of having regular black holes in these models.\n[Base
 d on: JCAP **07**\, 080 (2026)\; PRD **113**\, L041502 (2026)\; PRD **112*
 *\, 024051 (2025)\; PRD **110**\, 104056 (2024).]\n\nhttps://indico.itp.ac
 .cn/event/417/contributions/2942/
LOCATION:
URL:https://indico.itp.ac.cn/event/417/contributions/2942/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Diagonally gauged anomaly-free 6D supergravities and their vacua
DTSTART;VALUE=DATE-TIME:20261108T083000Z
DTEND;VALUE=DATE-TIME:20261108T090000Z
DTSTAMP;VALUE=DATE-TIME:20261023T102254Z
UID:indico-contribution-649-2958@indico.itp.ac.cn
DESCRIPTION:Speakers: Yi Pang (Tianjin University)\nWe describe a bounded 
 search for local and global anomaly-free six-dimensional $(1\,0)$ models w
 ith tensor number $T=1$ and gauge group containing a diagonal abelian fact
 or $U(1)_{R+}$. The abelian factor is the diagonal combination of the usua
 l gauged $U(1)_R$ and a $U(1)\\subset Sp(n_H)$ acting on hypermultiplets. 
 We have searched for locally and globally anomaly-free $G_1\\times U(1)_{R
 +}$ and $G_1\\times G_2\\times U(1)_{R+}$ models\, subject to restrictions
  on the ranks of the simple factors and on the maximal charges carried by 
 matter. We find that\, unlike the case of $U(1)_R$ gauged models which are
  relatively rare\, the diagonally gauged ones offer a rich landscape. We a
 lso study the 6D vacua of these models and find that they admit supersymme
 tric 6D Minkowski vacua\, for which the diagonal nature of the R-symmetry 
 gauging is necessary.\n\nhttps://indico.itp.ac.cn/event/417/contributions/
 2958/
LOCATION:
URL:https://indico.itp.ac.cn/event/417/contributions/2958/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Semileptonic $B\\to D$ and $B_s\\to D_S$ decays in the AdS/QCD Sof
 twall model
DTSTART;VALUE=DATE-TIME:20261108T073000Z
DTEND;VALUE=DATE-TIME:20261108T080000Z
DTSTAMP;VALUE=DATE-TIME:20261023T102254Z
UID:indico-contribution-649-2982@indico.itp.ac.cn
DESCRIPTION:Speakers: Miguel Angel Martin Contreras (University of South C
 hina)\nWe present a holographic calculation of the semileptonic decays $B\
 \to D$ and $B_s\\to D_s$ within the AdS/QCD Softwall Model. Heavy-light me
 sons are described by normalizable bulk modes\, while the flavor-changing 
 current $J_\\text{EW}^\\mu=\\bar{c}\\\,\\gamma^\\mu\\\,b$ is associated wi
 th a *massless* bulk vector field\, motivated by the UV scaling dimension 
 $\\Delta=3$ of the QCD current. An effective bulk interaction yields the *
 overlap integral* from which we extract the holographic Isgur-Wise functio
 n $\\xi(\\omega)$\, and the vector $f_+(q^2)$  and scalar $f_0(q^2)$  form
  factors. We also evaluate the Lepton Flavor Universality Ratios $R(D)$ an
 d $R(D_s)$\, comparing our predictions with lattice QCD and available expe
 rimental data. Finally\, we discuss the limitations of the leading-order h
 olographic description.\n\nhttps://indico.itp.ac.cn/event/417/contribution
 s/2982/
LOCATION:
URL:https://indico.itp.ac.cn/event/417/contributions/2982/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Timelike Entanglement First Law and Linearized Field Equations in 
 Higher Curvature Gravity
DTSTART;VALUE=DATE-TIME:20261108T063000Z
DTEND;VALUE=DATE-TIME:20261108T070000Z
DTSTAMP;VALUE=DATE-TIME:20261023T102254Z
UID:indico-contribution-649-2968@indico.itp.ac.cn
DESCRIPTION:Speakers: Jia-Rui Sun (Sun Yat-Sen University)\nWe investigate
  the timelike entanglement first law in holographic conformal field theori
 es whose bulk dual is Lovelock gravity. Using the double Wick rotation for
 mulation of timelike entanglement entropy together with the Jacobson-Myers
  entropy functional\, we compute the linear variation of holographic timel
 ike entanglement entropy for hyperbolic subregions. For cubic Lovelock gra
 vity\, we explicitly show that a single\, universal multiplicative renorma
 lization factor governs how higher curvature interactions enter the variat
 ions of both the entropy and the modular Hamiltonian\, leading to $\\Delta
  S=\\Delta\\langle H\\rangle$ for low-energy thermal excitations. We then 
 extend the analysis to Lovelock gravity of arbitrary order around the anti
 -de Sitter spacetime in the Fefferman-Graham gauge. For normalizable pertu
 rbations\, the variation of the Jacobson-Myers functional reduces to the E
 instein gravity's result multiplied by the same coupling-dependent factor 
 that renormalizes the effective Newtonian constant in the linearized field
  equations of Lovelock gravity. We further show that the boundary contribu
 tion vanishes in the conformal limit for the class of perturbations consid
 ered. Consequently\, the timelike entanglement first law is equivalent to 
 the linearized field equations of Lovelock gravity about the maximally sym
 metric background.\n\nhttps://indico.itp.ac.cn/event/417/contributions/296
 8/
LOCATION:
URL:https://indico.itp.ac.cn/event/417/contributions/2968/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Learning quark-gluon plasma properties holographically with neural
  ODEs
DTSTART;VALUE=DATE-TIME:20261108T060000Z
DTEND;VALUE=DATE-TIME:20261108T063000Z
DTSTAMP;VALUE=DATE-TIME:20261023T102254Z
UID:indico-contribution-649-2956@indico.itp.ac.cn
DESCRIPTION:Speakers: Song He (Ningbo University)\nWe use neural ODEs and 
 state-of-the-art lattice QCD thermodynamics to calibrate a holographic Ein
 stein-Maxwell-Dilaton model with Gauss-Bonnet corrections. The model quant
 itatively reproduces the equation of state at zero and finite baryon chemi
 cal potential and predicts the phase structure in the T-mu_B plane\, a tem
 perature-dependent ratio of shear viscosity over entropy\, and a peaked ra
 tio of bulk viscosity over entropy\, while remaining consistent with therm
 odynamic constraints.\n\nhttps://indico.itp.ac.cn/event/417/contributions/
 2956/
LOCATION:
URL:https://indico.itp.ac.cn/event/417/contributions/2956/
END:VEVENT
BEGIN:VEVENT
SUMMARY:A loop quantum gravity inspired effective action in spherically sy
 mmetric background and its applications
DTSTART;VALUE=DATE-TIME:20261107T073000Z
DTEND;VALUE=DATE-TIME:20261107T080000Z
DTSTAMP;VALUE=DATE-TIME:20261023T102254Z
UID:indico-contribution-649-2939@indico.itp.ac.cn
DESCRIPTION:Speakers: hongwei Tan (Hunan Institute of Technology)\nDevelop
 ing covariant effective descriptions of quantum-corrected black holes is a
 n important challenge in loop quantum gravity (LQG). In this talk\, I will
  present an LQG-inspired effective action in spherical symmetry that admit
 s the quantum Oppenheimer–Snyder (q-OS) black hole as a vacuum solution.
  Starting from a two-dimensional dilaton gravity framework obtained by int
 egrating out the angular degrees of freedom\, the construction introduces 
 an auxiliary constraint sector that promotes the mass parameter to a space
 time scalar and enforces its constancy on shell\, without introducing loca
 l propagating degrees of freedom. Using the covariant phase space formalis
 m\, I will discuss the associated Hamiltonian charges and black hole therm
 odynamics. The Wald entropy contains the classical area term together with
  a logarithmic correction\, while the auxiliary sector contributes a bound
 ary term essential for a consistent first law. I will then present a gener
 alized Birkhoff theorem showing that the vacuum sector admits a two-parame
 ter family of locally static solutions. The additional integration constan
 t is not fixed by asymptotic flatness\, and setting it to zero selects the
  q-OS branch. Its variation raises an integrability issue for the thermody
 namic phase space. These results provide a covariant framework for investi
 gating quantum-corrected black hole dynamics\, entropy\, and the physical 
 conditions required to select particular vacuum solutions.\n\nhttps://indi
 co.itp.ac.cn/event/417/contributions/2939/
LOCATION:
URL:https://indico.itp.ac.cn/event/417/contributions/2939/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Quantum Damping of Cosmological Shear: A New Prediction from Loop 
 Quantum Cosmologies
DTSTART;VALUE=DATE-TIME:20261107T070000Z
DTEND;VALUE=DATE-TIME:20261107T073000Z
DTSTAMP;VALUE=DATE-TIME:20261023T102254Z
UID:indico-contribution-649-2962@indico.itp.ac.cn
DESCRIPTION:Speakers: Wencong Gan (Jiangxi Normal University)\nWe study th
 e dynamics of the Bianchi I universe in modified loop quantum cosmology (m
 LQC-I) and uncover a robust mechanism for isotropization: the shear is dyn
 amically suppressed after the bounce and decays rapidly in the quantum pos
 tbounce regime\, independently of the equation of state of standard matter
  sources. This naturally drives the Universe toward a homogeneous and isot
 ropic expanding phase without fine-tuning. Our results show that mLQC-I pr
 ovides a new quantum-gravitational mechanism for suppressing anisotropies\
 , absent in other bounce models.\n\nhttps://indico.itp.ac.cn/event/417/con
 tributions/2962/
LOCATION:
URL:https://indico.itp.ac.cn/event/417/contributions/2962/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Static Vacuum Geometry Determines Gravitational Collapse and Cosmo
 logy
DTSTART;VALUE=DATE-TIME:20261107T063000Z
DTEND;VALUE=DATE-TIME:20261107T070000Z
DTSTAMP;VALUE=DATE-TIME:20261023T102254Z
UID:indico-contribution-649-2936@indico.itp.ac.cn
DESCRIPTION:Speakers: cong zhang (Beijing Normal University)\nBeyond gener
 al relativity\, regular black-hole geometries and modified cosmologies are
  often constructed independently\, raising the question of whether black h
 oles\, gravitational collapse\, and cosmology can still arise as different
  regimes of a common gravitational dynamics. We answer this question by sh
 owing that\, within the covariant spherically symmetric effective Hamilton
 ian framework\, the dynamics of gravity coupled to irrotational dust can b
 e determined directly from a prescribed static vacuum family\, although th
 e Hamiltonian reconstruction of that family is not unique. Requiring the r
 esulting dust dynamics to admit an FLRW sector further yields a necessary 
 and sufficient restriction on the static vacuum family and determines the 
 corresponding modified Friedmann equation. Thus\, static vacuum geometry d
 etermines the collapse dynamics\, while cosmological homogeneity feeds bac
 k to select the admissible static geometries. This generality may be roote
 d in the combined roles of general covariance and Birkhoff's theorem in th
 e underlying theory.\n\nhttps://indico.itp.ac.cn/event/417/contributions/2
 936/
LOCATION:
URL:https://indico.itp.ac.cn/event/417/contributions/2936/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Quantum geometry effects in quantum field theory: Hamiltonian cons
 traint generates gravity-matter entanglement in spherically symmetric loop
  quantum gravity
DTSTART;VALUE=DATE-TIME:20261107T060000Z
DTEND;VALUE=DATE-TIME:20261107T063000Z
DTSTAMP;VALUE=DATE-TIME:20261023T102254Z
UID:indico-contribution-649-2943@indico.itp.ac.cn
DESCRIPTION:Speakers: Gaoping Long (Jinan University)\nIn this work\, we a
 ddress a foundational challenge in quantum field theory on curved spacetim
 e by developing a consistent framework in spherically symmetric loop quant
 um gravity. We introduce a methodology for defining meaningful superpositi
 ons of quantum geometry and matter states near the semiclassical apparent 
 horizon. This is achieved by identifying a restricted subspace of the grav
 itational phase space\, which ensures unitary equivalence among Fock repre
 sentations of a scalar field across different quantum geometries. Within t
 he resulting well-defined state space\, we derive weak solutions to the qu
 antum Hamiltonian constraint of general relativity near the semiclassical 
 apparent horizon. Furthermore\, we generalize the Hartle-Hawking vacuum st
 ate to this quantum geometric framework. The resulting state exhibits the 
 inherent entanglement between geometry and matter\, which arises from the 
 quantum Hamiltonian constraint of general relativity. This work establishe
 s a principled framework for studying geometry-matter entanglement and off
 ers new insights into the quantum foundations of the black hole informatio
 n paradox.\n\nhttps://indico.itp.ac.cn/event/417/contributions/2943/
LOCATION:
URL:https://indico.itp.ac.cn/event/417/contributions/2943/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Scalarization of Bardeen spacetime
DTSTART;VALUE=DATE-TIME:20261107T090000Z
DTEND;VALUE=DATE-TIME:20261107T093000Z
DTSTAMP;VALUE=DATE-TIME:20261023T102254Z
UID:indico-contribution-649-2929@indico.itp.ac.cn
DESCRIPTION:Speakers: Long-Xing Huang (Lanzhou University)\nWe study the s
 calarization of the entire Bardeen spacetime which is constructed from a n
 onlinear magnetic monopole. For the pure Bardeen model\, it is well known 
 that there exist not only the general horizonless\, nonsingular Bardeen sp
 acetime solutions but also regular black hole (BH) solutions. When conside
 ring the Bardeen model coupled to a scalar field\, we find that under the 
 premise of solving throughout the entire spacetime (i.e.\, the radial coor
 dinate $r\\in[0\,\\infty)$ )\, there are two scenarios: one is the trivial
  pure Bardeen solution with a vanishing scalar field\, and the other is a 
 horizonless\, nonsingular scalarized Bardeen spacetime (SBS) solution. Dep
 ending on the value of the magnetic charge $q$\, these non-trivial solutio
 ns can be further divided into two categories: (1) When the magnetic charg
 e $q$ is below a certain critical value $q_c$ and the scalarization parame
 ter $a$ approaches the scalarization threshold $a_t$ from above (i.e.\, $a
 \\to a_t^+$)\, the scalar field vanishes\, and the spacetime reduces to th
 e horizonless\, nonsingular pure Bardeen spacetime. This behavior indicate
 s that this solution exhibits the general ``spontaneous" scalarization phe
 nomenon. (2) When $q \\geq q_c$\, in the limit $a \\to a_t^+$\, the scalar
  field is non-vanishing and the SBS approaches a ``frozen" SBS. Considerin
 g the importance of photon orbits in astronomical observations\, we analyz
 e the trajectories of photons around SBSs by analyzing null geodesics.\n\n
 https://indico.itp.ac.cn/event/417/contributions/2929/
LOCATION:
URL:https://indico.itp.ac.cn/event/417/contributions/2929/
END:VEVENT
BEGIN:VEVENT
SUMMARY:The complex conformal Kähler structure of type-D spacetimes
DTSTART;VALUE=DATE-TIME:20261107T093000Z
DTEND;VALUE=DATE-TIME:20261107T100000Z
DTSTAMP;VALUE=DATE-TIME:20261023T102254Z
UID:indico-contribution-649-2950@indico.itp.ac.cn
DESCRIPTION:Speakers: Haoran Xu (HIAS)\nThis is a work about the complex c
 onformal Kähler structure and the related duality symmetry of Plebański-
 Demiański class\, a kind of type-D spacetime. We reviewed the complex met
 ric and complex Kähler structure of complex spacetimes\, which has the co
 mplex valued metric and almost complex structure as well as the related po
 tential function. We find a SO(2\, C) duality transformation of Kerr-Taub-
 NUT class which maps Kerr metric into Taub-NUT metric continuously. What's
  more\, using the results above\, we get a Monge-Ampère equation which is
  equivalent to the vacuum Einstein equations and the solution of it contai
 ns the whole Plebański-Demiański Class\, and theoretically the type-D sp
 acetimes. Then we use toric reduction to obtain some moment polytopes and 
 then use this one can classify different type-D solutions based on the com
 plex conformal Kähler structure. We also find a complex Monge-Ampère equ
 ation and one can obtain the whold type-D by solving it. This is a joint w
 ork with Prof. Lars Andersson.\n\nhttps://indico.itp.ac.cn/event/417/contr
 ibutions/2950/
LOCATION:
URL:https://indico.itp.ac.cn/event/417/contributions/2950/
END:VEVENT
END:VCALENDAR