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BEGIN:VEVENT
SUMMARY:[online] Static black hole surrounded by dark matter and cloud of 
 strings
DTSTART;VALUE=DATE-TIME:20261109T013000Z
DTEND;VALUE=DATE-TIME:20261109T020000Z
DTSTAMP;VALUE=DATE-TIME:20261023T115633Z
UID:indico-contribution-651-2927@indico.itp.ac.cn
DESCRIPTION:Speakers: Ahmad Albadawi (Al-Hussien Bin Talal university)\nWe
  investigate a Schwarzschild-like black hole embedded in a combined enviro
 nment consisting of a Dehnen-type dark matter halo and a cloud of strings.
  We first construct the corresponding composite spacetime metric and exami
 ne its geometric properties\, including the horizon structure\, curvature 
 invariants\, and the validity of the classical energy conditions. Subseque
 ntly\, we explore the geodesic dynamics of test particles by analyzing the
  effective potential\, circular orbits\, and the innermost stable circular
  orbit (ISCO). We also study the optical appearance of the black hole by c
 omputing its shadow and assessing how the surrounding dark sector componen
 ts modify its observable features. Our results elucidate the influence of 
 dark matter distributions and string clouds on black hole geometry and dyn
 amics\, highlighting characteristic signatures that could serve as potenti
 al observational probes with current and future astrophysical facilities.\
 n\nhttps://indico.itp.ac.cn/event/417/contributions/2927/
LOCATION:
URL:https://indico.itp.ac.cn/event/417/contributions/2927/
END:VEVENT
BEGIN:VEVENT
SUMMARY:[online] Revisiting PBH Accretion\, Evaporation and Their Cosmolog
 ical Consequences
DTSTART;VALUE=DATE-TIME:20261108T093000Z
DTEND;VALUE=DATE-TIME:20261108T100000Z
DTSTAMP;VALUE=DATE-TIME:20261023T115633Z
UID:indico-contribution-651-2932@indico.itp.ac.cn
DESCRIPTION:Speakers: JITUMANI KALITA (Indian Institute of Technology Guwa
 hati)\nPrimordial black holes (PBHs) provide a unique probe of the early U
 niverse. Their cosmological evolution is governed by the competition betwe
 en mass accretion and Hawking evaporation. In this paper we look into the 
 details impact of accretion. Most of the earlier analysis relied on non-re
 lativistic accretion models. In this work\, we reinvestigate this in a ful
 ly relativistic framework for Kerr PBHs in the radiation-dominated era. We
  derive relativistic accretion rate and compute spin-dependent efficiency 
 $\\lambda_{\\rm Kerr}(a_*)$. Using this result\, we construct coupled evol
 ution equations for the PBH mass and spin that include both relativistic a
 ccretion and spin-dependent evaporation. Our analysis shows that relativis
 tic accretion significantly increases PBH masses and consequently suppress
 es their spins\, causing all PBHs to become effectively Schwarzschild well
  before evaporation. These effects strengthen the Big Bang Nucleosynthesis
  (BBN) bound on the initial PBH mass by a factor of $\\sim 4-5\,$ reduce t
 he mass required for survival to the present epoch to $\\sim 2.7 \\times 1
 0^{14} \\rm g\,$ and shift the viable particle like DM parameter space. No
 tably the early accretion induced spin-down effect further washes out the 
 well known high-frequency\, spin-induced feature in the high frequency sto
 chastic gravitational-wave background\, modifying predictions for future d
 etectors.\n\nhttps://indico.itp.ac.cn/event/417/contributions/2932/
LOCATION:
URL:https://indico.itp.ac.cn/event/417/contributions/2932/
END:VEVENT
BEGIN:VEVENT
SUMMARY:[online] Meissner Effect and Kerr/CFT Holography of Extremal Kerr
 –Bertotti–Robinson Black Holes
DTSTART;VALUE=DATE-TIME:20261109T023000Z
DTEND;VALUE=DATE-TIME:20261109T030000Z
DTSTAMP;VALUE=DATE-TIME:20261023T115633Z
UID:indico-contribution-651-2940@indico.itp.ac.cn
DESCRIPTION:Speakers: Siahaan Haryanto Mangaratua (Parahyangan Catholic Un
 iversity)\nThe Kerr–Bertotti–Robinson (Kerr–BR) spacetime is a recen
 tly constructed exact Einstein–Maxwell solution describing a rotating bl
 ack hole immersed in a homogeneous Bertotti–Robinson electromagnetic uni
 verse. Unlike the familiar Melvin-type magnetized Kerr families\, its asym
 ptotics are AdS₂ × S²\, the external field explicitly deforms the hori
 zon and extremality condition\, and its Maxwell and Weyl principal null di
 rections are misaligned. In this talk I examine two complementary near-hor
 izon phenomena of the extremal Kerr–BR black hole and show that both are
  governed by the same Kerr/CFT data. First\, I establish the Meissner effe
 ct in a manifestly gauge-invariant way: the horizon-tangent field strength
  vanishes\, so the external magnetic flux is fully expelled\, while the re
 sidual gauge coefficient survives only as a local Wilson-line term. Second
 \, I derive the near-horizon Breitenlohner–Freedman instability criterio
 n for a charged scalar probe\, expressed through two gauge-invariant combi
 nations — the shifted fibre momentum and the effective Kaluza–Klein el
 ectric coupling. Both the Meissner expulsion and the BF threshold turn out
  to be controlled by the twist parameter and gauge coefficient that enter 
 the holographic dictionary\, revealing them as two probes of a single extr
 emal throat whose structure is fixed by the external field.\n\nhttps://ind
 ico.itp.ac.cn/event/417/contributions/2940/
LOCATION:
URL:https://indico.itp.ac.cn/event/417/contributions/2940/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Torsion-Induced Four-Fermion Interactions in Gravitational Collaps
 e
DTSTART;VALUE=DATE-TIME:20261109T010000Z
DTEND;VALUE=DATE-TIME:20261109T013000Z
DTSTAMP;VALUE=DATE-TIME:20261023T115633Z
UID:indico-contribution-651-2964@indico.itp.ac.cn
DESCRIPTION:Speakers: Sagar Kumar Maity (S. N. Bose National Center for Ba
 sic Sciences)\nThe intrinsic spin of fermions generates torsion in spaceti
 me. This gives rise to a parity-violating\, nonuniversal four-fermion inte
 raction\, which is expected to become significant in dense matter\, such a
 s in early-universe cosmology or in neutron stars. We calculate the effect
  of the interaction term in a gravitationally collapsing gas of fermions w
 ith an isotropic spin distribution. We use the Raychaudhuri equation and t
 he focussing condition for congruences for a collapsing distribution of mu
 ltiple species of fermions\, ignoring other interactions. We establish tha
 t a repulsive contribution can arise depending on how torsion couples with
  different chiralities. The effect of the interaction starts to dominate a
 s density increases\, accelerating or decelerating the collapse depending 
 on the torsional coupling constants of different fermions.\n\nBased on : S
 . G. Choudhury\, S. K. Maity\, and A. Lahiri. Torsional four-fermion inter
 action and the Raychaudhuri equation. Eur. Phys. J. C\, 84(12):1304\, (202
 4).\n\nhttps://indico.itp.ac.cn/event/417/contributions/2964/
LOCATION:
URL:https://indico.itp.ac.cn/event/417/contributions/2964/
END:VEVENT
BEGIN:VEVENT
SUMMARY:A Neutron Star Hidden Inside a Black Hole
DTSTART;VALUE=DATE-TIME:20261109T033000Z
DTEND;VALUE=DATE-TIME:20261109T040000Z
DTSTAMP;VALUE=DATE-TIME:20261023T115633Z
UID:indico-contribution-651-2937@indico.itp.ac.cn
DESCRIPTION:Speakers: Chen Tan (Lanzhou University)\nWe investigate dark m
 atter admixed neutron stars in which the neutron star coexists with an ani
 sotropic dark matter halo described by the Einasto density profile\, a mod
 el recently shown to produce regular\, singularity-free black hole solutio
 ns~[Phys. Rev. D \\textbf{113}\, 043011 (2026)].\nSolving the modified Tol
 man--Oppenheimer--Volkoff equations with two different equations of state 
 (BSk19 and SLy4)\, we find that the dark matter halo significantly alters 
 the neutron star structure.\nFurthermore\, for a specific range of halo pa
 rameters\, $g_{rr}^{-1}$ changes sign outside the stellar surface\, formin
 g an event horizon with the neutron star persisting as a regular configura
 tion inside it--- ``neutron stars in black holes''.\nThis configuration ap
 pears in both equations of state and does not depend on a specific choice 
 of the equation of state.\nThe discovery of this configuration provides a 
 new perspective and a concrete computable instance for the study of what l
 ies inside a black hole.\n\nhttps://indico.itp.ac.cn/event/417/contributio
 ns/2937/
LOCATION:
URL:https://indico.itp.ac.cn/event/417/contributions/2937/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Neutron stars more compact than black holes
DTSTART;VALUE=DATE-TIME:20261109T030000Z
DTEND;VALUE=DATE-TIME:20261109T033000Z
DTSTAMP;VALUE=DATE-TIME:20261023T115633Z
UID:indico-contribution-651-2948@indico.itp.ac.cn
DESCRIPTION:Speakers: Shonglong Li ()\nhttps://indico.itp.ac.cn/event/417/
 contributions/2948/
LOCATION:
URL:https://indico.itp.ac.cn/event/417/contributions/2948/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Shadow of rotating black hole surrounded by dark matter
DTSTART;VALUE=DATE-TIME:20261109T003000Z
DTEND;VALUE=DATE-TIME:20261109T010000Z
DTSTAMP;VALUE=DATE-TIME:20261023T115633Z
UID:indico-contribution-651-2924@indico.itp.ac.cn
DESCRIPTION:Speakers: Haiyuan Feng (Shanxi Normal University)\n暗物质
 （DM）是宇宙的基本组成成分，因此有必要研究其对黑洞
 （BH）阴影的影响，尤其是事件视界望远镜（EHT）观测所
 证实的旋转黑洞。本文利用 Newman–Janis 算法（NJA），将
 暗物质环绕的施瓦西黑洞解推广为轴对称的克尔黑洞解
 ，并研究其事件视界与能层结构。通过分析零测地线，
 我们考察了暗物质质量（(\\Delta M)）对黑洞阴影半径、形
 变及相关能量发射率的影响。结果表明，当暗物质质量
 低于某一临界值时，其影响可以忽略；一旦超过该阈值
 ，黑洞的各类结构均显著扩张。此外，即使黑洞具有较
 高自旋，暗物质仍有助于其阴影保持近圆形轮廓。较大
 暗物质质量引起的显著结构扩张可能超出当前观测约束
 。这表明，为与天体物理观测保持一致，黑洞紧邻区域
 内应不存在暗物质，或其中的局域暗物质质量必须低于
 该临界值。\n\nhttps://indico.itp.ac.cn/event/417/contributions/2924/
LOCATION:
URL:https://indico.itp.ac.cn/event/417/contributions/2924/
END:VEVENT
BEGIN:VEVENT
SUMMARY:A Designer’s Guide to Lunar Far-Side Interferometer Array: Power
  Spectrum Measurement and Cosmological Information in the Dark Ages
DTSTART;VALUE=DATE-TIME:20261108T073000Z
DTEND;VALUE=DATE-TIME:20261108T080000Z
DTSTAMP;VALUE=DATE-TIME:20261023T115633Z
UID:indico-contribution-651-2974@indico.itp.ac.cn
DESCRIPTION:Speakers: Yuewei Wen (National Astronomical Observatories of C
 hina\, Chinese Academy of Sciences)\nThe 21-cm signal from the cosmic Dark
  Ages is a powerful probe of cosmology and\ninflation\, but its science po
 tential depends critically on the design of the lunar\nfar-side interferom
 eter that will observe it. We derive closed-form relations\nconnecting the
  array design to the two goals this epoch offers: measuring a chosen\nsmal
 l scale\, and extracting the largest possible cosmological information fro
 m the\nsurvey as a whole. These relations provide a quantitative prescript
 ion of resources required to reach a stated detection threshold at a tunab
 le scale of interest and show that the optimal configuration for the power
  spectrum at that scale is to split the collecting area among multiple sta
 tions. For fixed resources\, splitting a single array into two or three st
 ations\ncan raise S/N at $k_\\perp = 1\\\,\\mathrm{Mpc}^{-1}$ by factors o
 f about 10 and 16\, reaching two orders of magnitude at smaller scales. Fo
 r the purpose of cosmological parameter constraints\, we derive where the 
 cosmological information accessible to a lunar array resides\, in redshift
  and in transverse wavenumber\, and find that thermal noise erodes the oft
 en-quoted $10^{12}$ modes to an effective budget of order $10^{4}$\, half 
 of which accumulates below $z \\approx 36$. As a demonstration\, we foreca
 st $\\sigma(\\alpha_s) = 0.034$ for the running of the spectral index assu
 ming a near-term array configuration\, illustrating both the prospects and
  the limitations implied by these relations.\n\nhttps://indico.itp.ac.cn/e
 vent/417/contributions/2974/
LOCATION:
URL:https://indico.itp.ac.cn/event/417/contributions/2974/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Too Quiet to Be Ordinary: Little Red Dots
DTSTART;VALUE=DATE-TIME:20261108T090000Z
DTEND;VALUE=DATE-TIME:20261108T093000Z
DTSTAMP;VALUE=DATE-TIME:20261023T115633Z
UID:indico-contribution-651-2944@indico.itp.ac.cn
DESCRIPTION:Speakers: INDU KALPA DIHINGIA (Ningbo University)\nJWST's litt
 le red dots (LRDs) are unexpectedly non-variable. We present a semi-analyt
 ic framework for variability in super-Eddington slim disks with winds\, co
 mbining photon trapping\, photospheric averaging\, and diffusion filtering
 \, calibrated on ordinary quasars. Forward-modeling the TWINKLE non-detect
 ions of 18 LRDs\, we derive a lower limit ṁ ≳ 60 (95% confidence) for 
 10⁷ M⊙ black holes\, excluding sub-Eddington interpretations\, and pre
 dict mass-segregated variability and suppressed X-ray variability that are
  testable with future observatories.\n\nhttps://indico.itp.ac.cn/event/417
 /contributions/2944/
LOCATION:
URL:https://indico.itp.ac.cn/event/417/contributions/2944/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Measuring Geometric Distances Using Interferometry and Reverberati
 on Mapping of Broad-line Regions
DTSTART;VALUE=DATE-TIME:20261108T083000Z
DTEND;VALUE=DATE-TIME:20261108T090000Z
DTSTAMP;VALUE=DATE-TIME:20261023T115633Z
UID:indico-contribution-651-2967@indico.itp.ac.cn
DESCRIPTION:Speakers: Yan-Rong Li (Institute of High Energy Physics)\nThe 
 geometric distances of active galactic nuclei (AGNs) are challenging to me
 asure because of their exceptionally compact structure\, yet vast cosmic d
 istances. A combination of spectroastrometry and reverberation mapping (SA
 RM) of broad-line regions (BLRs) constitutes a novel means to probe the ge
 ometric distance of AGNs\, which has recently become practically feasible 
 owing to successful interferometric observations with the Very Large Teles
 cope Interferometer/GRAVITY. Here\, we perform SARM analysis of four nearb
 y quasars: Mrk 509\, PDS 456\, 3C 273\, and NGC 3783. Results for the form
 er two are reported for the first time\, and the latter two are revisited 
 using our improved BLR dynamical modeling that includes the radial-depende
 nt responsivity of BLRs. This allows us to self-consistently account for t
 he emissivity weighting of the BLR in spectroastrometry and responsivity w
 eighting in reverberation mapping. We obtain angular-diameter distances of
  the four quasars\, from which we derive a Hubble constant of H0=69(−10 
 +12)km/s/Mpc . Although this constitutes a large uncertainty for a measure
 ment of H0\, it is anticipated that the precision will improve to a compet
 itive level once a greater number of AGNs are accessible following the upg
 rade of GRAVITY in the near future.\n\nhttps://indico.itp.ac.cn/event/417/
 contributions/2967/
LOCATION:
URL:https://indico.itp.ac.cn/event/417/contributions/2967/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Cosmological forecast from bispectrum of 21cm intensity mapping
DTSTART;VALUE=DATE-TIME:20261108T070000Z
DTEND;VALUE=DATE-TIME:20261108T073000Z
DTSTAMP;VALUE=DATE-TIME:20261023T115633Z
UID:indico-contribution-651-2952@indico.itp.ac.cn
DESCRIPTION:Speakers: Yu Sang (Yangzhou University)\nhttps://indico.itp.ac
 .cn/event/417/contributions/2952/
LOCATION:
URL:https://indico.itp.ac.cn/event/417/contributions/2952/
END:VEVENT
BEGIN:VEVENT
SUMMARY:RadioSkySim: A Flexible and Scalable Python Framework for Radio-As
 tronomical Sky Simulation
DTSTART;VALUE=DATE-TIME:20261108T063000Z
DTEND;VALUE=DATE-TIME:20261108T070000Z
DTSTAMP;VALUE=DATE-TIME:20261023T115633Z
UID:indico-contribution-651-2953@indico.itp.ac.cn
DESCRIPTION:Speakers: Luciano Barosi (Universidade Federal de Campina Gran
 de)\n**RadioSkySim: A Flexible and Scalable Python Framework for Radio-Ast
 ronomical Sky Simulation**\n\nRadioSkySim is a Python-based sky simulation
  framework developed within the BINGO Collaboration to support the modelin
 g\, analysis\, and validation of radio-astronomical observations. Designed
  with an emphasis on modularity\, extensibility\, and computational effici
 ency\, it provides a flexible environment for generating realistic simulat
 ed observations while maintaining a clear separation between scientific mo
 dels and computational infrastructure.\n\nThe framework implements a libra
 ry of instrumental beams with polarization support\, astronomical radio so
 urces\, local sources\, and GNSS satellites\, enabling the construction of
  complex and configurable observing scenarios. These components can be com
 bined to generate time-ordered data (TOD)\, currently stored in NetCDF for
 mat\, and to support subsequent map-making and analysis workflows.\n\nRadi
 oSkySim adopts a hexagonal architecture that facilitates the integration o
 f different computational backends and scientific models without coupling 
 them to the core simulation logic. Its architecture also incorporates cach
 ing and database persistence mechanisms\, together with multi-core executi
 on capabilities\, allowing simulations to be efficiently reused\, scaled\,
  and integrated into larger data-processing pipelines.\n\nBeyond its curre
 nt capabilities\, the framework was designed as a foundation for more dema
 nding simulation scenarios\, including GPU-accelerated computation\, addit
 ional classes of sky and foreground components\, and increasingly sophisti
 cated instrument models. This approach aims to provide the BINGO Collabora
 tion with a sustainable simulation infrastructure capable of supporting bo
 th experimental development and scientific analysis.\n\nIn this talk\, we 
 present the architecture and main capabilities of RadioSkySim\, discuss it
 s current implementation and use cases\, and illustrate how its design ena
 bles the progressive incorporation of new physical models\, instrumental e
 ffects\, and computational strategies.\n\nhttps://indico.itp.ac.cn/event/4
 17/contributions/2953/
LOCATION:
URL:https://indico.itp.ac.cn/event/417/contributions/2953/
END:VEVENT
BEGIN:VEVENT
SUMMARY:A new window for astrophysics from the lunar orbit
DTSTART;VALUE=DATE-TIME:20261108T060000Z
DTEND;VALUE=DATE-TIME:20261108T063000Z
DTSTAMP;VALUE=DATE-TIME:20261023T115633Z
UID:indico-contribution-651-2985@indico.itp.ac.cn
DESCRIPTION:Speakers: Xuelei Chen ()\nI shall present the Discovering Sky 
 at the Longest wavelength (DSL) mission\, also known as the Hongmeng missi
 on in Chinese\, which aims to unveil the sky at this low frequency band by
  using an array of microsatellites flying in formation on an orbit around 
 the Moon. The mission will make highly precise 21cm global spectrum measur
 ement in the 0.1-30 MHz band and in the 30-120 MHz band\, without being hi
 ndered by ionospheric distortion\, radio frequence interferences\, or grou
 nd reflections. This will reveal the cosmic evolution history from the dar
 k ages to cosmic dawn. The satellite array will also make high resolution 
 full sky maps in the 0.1-30 MHz band\, which will provide new observationa
 l clues to the study of the Galactic interstellar medium\, extragalactic r
 adio sources\, and solar and planetary activities. Observation in this new
  window may also reveal unknown new objects or phenomena. The DSL mission 
 science team welcomes the participation of the international science commu
 nity.\n\nhttps://indico.itp.ac.cn/event/417/contributions/2985/
LOCATION:
URL:https://indico.itp.ac.cn/event/417/contributions/2985/
END:VEVENT
BEGIN:VEVENT
SUMMARY:A continuous wave window into neutron star structure
DTSTART;VALUE=DATE-TIME:20261107T093000Z
DTEND;VALUE=DATE-TIME:20261107T100000Z
DTSTAMP;VALUE=DATE-TIME:20261023T115633Z
UID:indico-contribution-651-2976@indico.itp.ac.cn
DESCRIPTION:Speakers: Ayush Hazarika (International Centre for Theoretical
  Physics Asia-Pacific (ICTP-AP)\, University of Chinese Academy of Science
 s)\nEvery rapidly spinning neutron star with slight asymmetry would broadc
 ast a continuous hum of gravitational waves (GW). None of these signals ha
 s been detected yet\, but the silence itself is measurable: searches now s
 et upper limits on the GW amplitude of dozens of known pulsars\, and for a
  growing subset those limits dig below the energy budget available from th
 e stars’ own spin-down. We ask what this kind of data\, can say about th
 e interior of a neutron star. The amplitude of the continous signal depend
 s on how much matter the star carries in its deformation and how that matt
 er is distributed\, its moment of inertia\, which in turn is fixed by the 
 unknown equation of state of dense matter. This opens a route to the neutr
 on star mass-radius relation that is fully independent of the X-ray pulse-
 profile and binary-merger measurements that anchor current constraints. We
  build a hierarchial Bayesian pipeline that propagates simulated amplitude
  limits\, treated consistently as non-detections\, through stellar-structu
 re calculations to the mass-radius plane\, marginalizing over the unknown 
 deformations of the pulsar population. Rather than claiming a new measurem
 ent\,\nwe chart the sensitivity frontier: how deep continuous-wave searche
 s must go before they begin to weigh in on dense matter on their own.\n\nh
 ttps://indico.itp.ac.cn/event/417/contributions/2976/
LOCATION:
URL:https://indico.itp.ac.cn/event/417/contributions/2976/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Gravitational wave lensing beyond geometric optics
DTSTART;VALUE=DATE-TIME:20261107T090000Z
DTEND;VALUE=DATE-TIME:20261107T093000Z
DTSTAMP;VALUE=DATE-TIME:20261023T115633Z
UID:indico-contribution-651-2931@indico.itp.ac.cn
DESCRIPTION:Speakers: Li Zhao (Peking Univ.)\nhttps://indico.itp.ac.cn/eve
 nt/417/contributions/2931/
LOCATION:
URL:https://indico.itp.ac.cn/event/417/contributions/2931/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Gravitational-Wave Signatures of Source Motion: Probing Dynamical 
 Environments and Merger Recoils
DTSTART;VALUE=DATE-TIME:20261107T070000Z
DTEND;VALUE=DATE-TIME:20261107T073000Z
DTSTAMP;VALUE=DATE-TIME:20261023T115633Z
UID:indico-contribution-651-2933@indico.itp.ac.cn
DESCRIPTION:Speakers: Li Jin (Chongqing University)\nThe motion of black-h
 ole systems can leave distinctive imprints on gravitational-wave signals\,
  offering a unique window into both their surrounding environments and mer
 ger dynamics. In this talk\, I will discuss two representative effects ass
 ociated with black-hole motion across different stages of binary evolution
 . First\, I will consider stellar-mass binary black holes orbiting a super
 massive black hole in galactic nuclei\, where the long-term orbital motion
  produces characteristic modulations in the observed gravitational-wave si
 gnal. These modulations provide an opportunity to probe the mass\, spin\, 
 and orientation of the central supermassive black hole\, as well as the dy
 namical configuration of the system. I will then turn to the recoil of the
  merger remnant caused by asymmetric gravitational-wave emission. Such rec
 oil signatures can be imprinted directly in the gravitational-wave signal 
 and may be detectable with next-generation ground- and space-based observa
 tories. Our forecasts indicate that these observations can substantially i
 mprove our ability to measure supermassive black-hole properties and chara
 cterize black-hole merger dynamics. Together\, these studies highlight the
  broader role of source motion in gravitational-wave astronomy: rather tha
 n being a secondary correction\, it can serve as a powerful probe of other
 wise inaccessible astrophysical information and open new opportunities for
  studying black holes across multiple scales and frequency bands.\n\nhttps
 ://indico.itp.ac.cn/event/417/contributions/2933/
LOCATION:
URL:https://indico.itp.ac.cn/event/417/contributions/2933/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Nonlinear Quasinormal Modes in the Ringdown of GW250114: Observati
 onal Evidence for Nonlinear Gravitational Waves
DTSTART;VALUE=DATE-TIME:20261107T073000Z
DTEND;VALUE=DATE-TIME:20261107T080000Z
DTSTAMP;VALUE=DATE-TIME:20261023T115633Z
UID:indico-contribution-651-2975@indico.itp.ac.cn
DESCRIPTION:Speakers: Yifan Wang ()\nThe ringdown signal following a binar
 y black hole merger offers a crucial avenue for investigating black hole p
 roperties and testing General Relativity in strong-field regimes. Beyond l
 inear quasinormal modes\, General Relativity predicts the existence of sec
 ond-order quasinormal modes arising from the nonlinear coupling of gravita
 tional waves. This talk presents an analysis of the ringdown signal from t
 he gravitational-wave event GW250114\, demonstrating observational evidenc
 e for second-order quasinormal modes. Through a systematic calculation of 
 coupling coefficients for the first ten second-order modes\, and the appli
 cation of a novel data analysis method\, we find a Bayes factor of 62 supp
 orting the presence of these nonlinear modes at a selected ringdown starti
 ng time. A zero-amplitude hypothesis is excluded with a significance of 3.
 4 sigma\, and the inferred amplitudes and complex frequencies are consiste
 nt with General Relativity predictions. We will discuss the analysis metho
 dology\, key results\, and their physical implications\, illustrating how 
 black hole spectroscopy can be extended into the nonlinear regime and prov
 iding a new observational window for testing the nonlinear structure of Ge
 neral Relativity.\n\nhttps://indico.itp.ac.cn/event/417/contributions/2975
 /
LOCATION:
URL:https://indico.itp.ac.cn/event/417/contributions/2975/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Astrophysical lessons from merging binary black holes: gap and hig
 hly spinning subpopulation
DTSTART;VALUE=DATE-TIME:20261107T083000Z
DTEND;VALUE=DATE-TIME:20261107T090000Z
DTSTAMP;VALUE=DATE-TIME:20261023T115633Z
UID:indico-contribution-651-2972@indico.itp.ac.cn
DESCRIPTION:Speakers: Tong Hui (Monash University/CITA)\nUncovering the or
 igins of binary black holes through gravitational-wave detections provides
  a powerful probe of the evolution\, interactions\, and environments of ma
 ssive stars. Stellar theory predicts a forbidden range of black-hole masse
 s between 50-130Msun due to pair-instability supernovae. In this talk\, I 
 will present our latest observational evidence of the pair-instability gap
  in the distribution of black hole masses. While the gap is not present in
  the distribution of primary masses\, it appears unambiguously in the dist
 ribution of secondary masses. The location of the gap lines up well with a
  previously identified transition in the binary black-hole spin distributi
 on\; binaries with primary components in the gap tend to spin more rapidly
  than those below the gap. We interpret these findings as evidence for a s
 ubpopulation of hierarchical mergers. I will also highlight the concurrent
  signatures of hierarchical mergers. If time permits\, I will introduce th
 e results of the astrophysical distributions of merging compact objects in
  the latest GWTC-5 LVK paper.\n\nhttps://indico.itp.ac.cn/event/417/contri
 butions/2972/
LOCATION:
URL:https://indico.itp.ac.cn/event/417/contributions/2972/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Clock Noise Suppression in Space-Based Gravitational Wave Detectio
 n
DTSTART;VALUE=DATE-TIME:20261107T063000Z
DTEND;VALUE=DATE-TIME:20261107T070000Z
DTSTAMP;VALUE=DATE-TIME:20261023T115633Z
UID:indico-contribution-651-2934@indico.itp.ac.cn
DESCRIPTION:Speakers: Yujie Tan (Huazhong University of Science and Techno
 logy)\nSpace-based gravitational wave detection (e.g.\, LISA\, Taiji\, and
  TianQin) relies on ultra-high-precision inter-satellite laser interferome
 try. However\, clock noise is approximately two orders of magnitude higher
  than the detector noise floor\, which severely limits the overall detecti
 on sensitivity and becomes a critical constraint for space-based gravitati
 onal wave observatories. To address this challenge\, this presentation rep
 orts our recent progress in both theoretical and experimental studies on c
 lock noise suppression.\n\nhttps://indico.itp.ac.cn/event/417/contribution
 s/2934/
LOCATION:
URL:https://indico.itp.ac.cn/event/417/contributions/2934/
END:VEVENT
BEGIN:VEVENT
SUMMARY:GW Astronomy with TianQin
DTSTART;VALUE=DATE-TIME:20261107T060000Z
DTEND;VALUE=DATE-TIME:20261107T063000Z
DTSTAMP;VALUE=DATE-TIME:20261023T115633Z
UID:indico-contribution-651-2965@indico.itp.ac.cn
DESCRIPTION:Speakers: Yi-Ming Hu ()\nThe millihertz gravitational-wave ban
 d offers a new view of compact objects and black holes across cosmic histo
 ry. TianQin\, a planned space-based observatory\, will explore this band t
 hrough long-duration observations. In this talk\, I will discuss its astro
 physical prospects\, from Galactic double white dwarfs and stellar-mass bl
 ack hole binaries to massive black hole mergers and extreme-mass-ratio ins
 pirals. These sources address questions at different scales: how compact b
 inaries form and evolve\, how massive black holes grow through mergers\, a
 nd how stellar remnants move within galactic nuclei. I will also consider 
 how joint observations with other gravitational-wave detectors and electro
 magnetic telescopes could improve source characterization and enable multi
 -messenger studies. I will conclude by introducing the proposed TianQin Mo
 ck Data Challenge (MDC)\, currently in preparation\, and its potential rol
 e in developing and testing the data-analysis methods needed to realize th
 ese science goals.\n\nhttps://indico.itp.ac.cn/event/417/contributions/296
 5/
LOCATION:
URL:https://indico.itp.ac.cn/event/417/contributions/2965/
END:VEVENT
END:VCALENDAR