Previous Webinar Series


The 5th webinar talks


Semtember 12 (Monday) 2022, 10:00-12:00 JST

Talks (Speakers & Titles):

  1. Speaker: Kotaro Tamaoka (Nihon University)(slides)
    Title: Non-Equilibrating a Black Hole with Inhomogeneous Quantum Quench

Abstract: We study non-equilibrium processes in AdS/CFT induced by quantum quench using spatially inhomogeneous Hamiltonians, called the sine-square-deformed (SSD) Hamiltonians. When the CFT admits a holographic description, these quenches induce inhomogeneous deformations of the black hole in the AdS bulk. In particular, at late enough times after the quench by the SSD Hamiltonian, the horizon of the bulk black hole asymptotically "touches" the boundary. If time permits, we also discuss several implications on the boundary CFT side and possible applications to quantum many-body systems in the real experimental setup.
arXiv: 2112.14388

  1. Speaker: Junsei Tokuda (Kobe University)(slides)
    Title: Phenomenological Motivation for Gravitational Positivity Bounds: A Case Study of Dark Sector Physics

Abstract: Same as the arXiv version
arXiv: 2205.12835

The 4th webinar talks

July 14 (Thursday) 2022, 16:00-18:00 JST

Talks (Speakers & Titles):

  1. Speaker: Daisuke Yamauchi (Kanagawa University)(slides)
    Title: Signature of primordial non-Gaussianity on 21-cm power spectrum from dark ages
    arXiv: 2203.15599

  2. Speaker: Yuki Osawa (Nagoya University)(slides)
    Title: Particle Creation and Entanglement in Dispersive Model with Step Velocity Profile
    arXiv: 2204.08684

  3. Speaker: Daiki Yamaguchi (Kindai University)(slides)
    Title: Running Newton Coupling, Scale Identification and Black Hole Thermodynamics
    arXiv: 2204.09892

The 3RD webinar talks

May 9 (Monday) 2022, 13:00-15:00 JST

Talks (Speakers & Titles):

  1. Speaker: Toshiya Namikawa (Kavli IPMU)(slides)
    Title: Finding Evidence for Inflation and the Origin of Galactic Magnetic Fields with CMB Surveys
    arXiv: 2201.02204

  2. Speaker: Youka Kaku (Nagoya University)(slides)
    Title: Creating stars orbiting in AdS
    arXiv: 2202.07807

  3. Speaker: Kai Murai (ICRR, University of Tokyo)(slides)
    Title: Gravitational waves detectable in laser interferometers from axion-SU(2) inflation
    arXiv: 2203.15273

The 2nd webinar talks

March 30 (Wednesday) 2022, 13:00-15:00 JST

Talks (Speakers & Titles):

  1. Speaker: Akihiro Ishibashi (Kindai Univ.)(slides)
    Title: The averaged null energy condition on holographic evaporating black holes
    arXiv: 2111.05151

  2. Speaker: Tetsuya Hashimoto (National Chung Hsing Univ.)(slides)
    Title: Upper limits on Einstein's weak equivalence principle placed by uncertainties of dispersion measures of fast radio bursts
    arXiv: 2111.11447

  3. Speaker: Hidetoshi Omiya (TAP, Kyoto Univ.)(slides)
    Title: Adiabatic evolution of the self-interacting axion field around rotating black holes
    arXiv: 2201.04382

The 1st webinar talks

February 10 (Thursday) 2022, 16:00-18:00 JST

Talks (Speakers & Titles):

  1. Speaker: Sousuke Noda (Miyakonojo College)(slides)
    Title: Alfvénic superradiance for a monopole magnetosphere around a Kerr black hole
    arXiv: 2111.01149

  2. Speaker: Kazufumi Takahashi (YITP, Kyoto Univ.)(slides)
    Title: Invertible disformal transformations with higher derivatives
    arXiv: 2111.11634

  3. Speaker: Takuya Takahashi (TAP, Kyoto Univ.)(slides)
    Title: Axion cloud evaporation during inspiral of black hole binaries
    arXiv: 2112.05774

PAST WEBINARS: 2020-2021

The 10TH webinar SELECTED talks

October 29 (Fri) 2021, 10:00- JST

Selected Talks (Speakers & Titles):

  1. Speaker: Kanji Nishii (Kobe Univ.) (slides)
    Title: Spiky strings in de Sitter space
    arXiv: 2102.09746

  2. Speaker: Takahisa Igata (KEK) (slides)
    Title: Photon emission from inside the innermost stable circular orbit
    arXiv: 2102.13427

  3. Speaker: Beatriz Elizaga Navascués (Waseda Univ.) (slides)
    Title: Primordial perturbations in kinetically dominated regimes of general relativity and hybrid quantum cosmology
    arXiv: 2106.05628

The 9TH webinar SELECTED talks

September 10 (Fri.) 2021, 13:00 JST (UTC+0900)

Selected Talks (Speakers & Titles):

  1. Speaker: Yasutaka Koga (Nagoya Univ.) (Slide)
    Title: Photon surfaces in less symmetric spacetimes

  2. Speaker: So Okano (Tokyo Institute of Technology) (Slide)
    Title: When does the Schwinger Preheating Occur?

  3. Speaker: Priti Gupta (Kyoto Univ.) (Slide)
    Title: Importance of tidal resonances in extreme-mass-ratio inspirals

The 8TH webinar SELECTED talks

July 15 (Thu.) 2021, 15:00 JST (UTC+0900)

Selected Talks (Speakers & Titles):

  1. Speaker: Akira Matsumura (Kyushu University) (Slide)
    Title: Field-induced entanglement in spatially superposed objects

  2. Speaker: Hayato Motohashi (Kogakuin University) (Slide)
    Title: Exact solution for wave scattering from black holes

  3. Speaker: Hiroki Asami (Nagoya University) (Slide)
    Title: Thermal equilibrium states and instability of self-gravitating particles in an asymptotically AdS spacetime

The 7TH webinar SELECTED talks

June 2 (Wed) 2021, 16:30 JST (UTC+0900)

Selected Talks (Speakers & Titles):

  1. Speaker: Taiga Miyachi (Kobe University) (Slide)
    Title: False vacuum decay in a two-dimensional black hole spacetime

  2. Speaker: Taishi Ikeda (Sapienza University of Rome) (Slide)
    Title: Black-hole microstate spectroscopy: ringdown, quasinormal modes, and echoes

  3. Speaker: Yusuke Mikura (Nagoya University) (Slide)
    Title: Minimal k-inflation in light of the conformal metric-affine geometry

The 6TH webinar SELECTED talks

May 6 (Thu) 2021, 14:00 JST (UTC+0900)

Selected Talks (Speakers & Titles):

  1. Speaker: Keitaro Tomikawa (Rikkyo Univ.) (Slide)
    Title: Perturbations and quasi-normal modes of black holes with time-dependent scalar hair in shift-symmetric scalar-tensor theories

  2. Speaker: Teruaki Suyama (Tokyo Institute of Technology) (Slide)
    Title: Revisiting non-Gaussianity in non-attractor inflation models in the light of the cosmological soft theorem

  3. Speaker: Suro Kim (Kobe Univ.) (Slide)
    Title: Perturbative unitarity in quasi-single field inflation

The 5TH webinar SELECTED talks


Mar 29 (Mon) 2021, 10:00 JST (UTC+0900)

Selected Talks (Speakers & Titles):

  1. Speaker: Katsuki Aoki (YITP, Kyoto Univ.)
    Title: Non-linearly ghost-free higher curvature gravity (Slide)

  2. Speaker: Hidetoshi Omiya (Kyoto Univ.)
    Title: Renormalization group analysis of superradiant growth of self-interacting axion cloud (Slide)

  3. Speaker: Keisuke Izumi (Nagoya Univ.)
    Title: Area bound for surfaces in generic gravitational field (Slide)

The 4TH webinar SELECTED talks


Jan. 26 (Tue.) 2021, 13:00 JST (UTC+0900)

Speakers & Titles:

  1. Speaker: Yuto Minami (RCNP)
    Title: New Extraction of the Cosmic Birefringence from the Planck 2018 Polarization Data (Slide)
    ArXiv No: 2011.11254

  2. Speaker: Takuya Katagiri (Rikkyo Univ.)
    Title: Instabilities of charged anti-de Sitter black holes (Slide)
    ArXiv No: 2006.10301

  3. Speaker: Valeri Vardanyan (IPMU)
    Title: Cross-correlation of the astrophysical gravitational-wave background with galaxy clustering (Silde)
    ArXiv No: 1910.08353

The 3RD webinar SELECTED talks


Dec. 16 (Wed.) 2020, 10:00 JST (UTC+0900)

Speakers & Titles:

  1. Speaker: Keisuke Nakashi (Rikkyo Univ.)
    Title: Towards rotating non-circular black holes in string-inspired gravity (slide)
    ArXiv no.:

  2. Speaker: Shin'ichi Hirano (Nagoya Univ.)
    Title: UV sensitive one-loop matter power spectrum in degenerate higher-order scalar-tensor theories (slide)
    ArXiv no.:

  3. Speaker: Shao-Jiang Wang (KIAS/Tufts)
    Title: Effective picture of bubble expansion (slide)
    ArXiv no.:

The 2nd webinar SELECTED talks


Oct. 22 (Thu.) 2020, 16:00 JST (UTC+0900)

Speakers & Titles:

  1. Speaker: Yasuyuki Hatsuda (Rikkyo Univ.)
    Title: An alternative to the Teukolsky equation (slide)
    ArXiv no.:

  2. Speaker: Yuichiro Tada (Nagoya Univ.)
    Title: A manifestly covariant theory of multifield stochastic inflation in phase space (slide)
    ArXiv no.:

  3. Speaker: Kei Yamada (Kyoto Univ.)
    Title: Resonant gravitational waves in dynamical Chern-Simons-axion gravity (slide)
    ArXiv no.:

The 1st webinar SELECTED talks


Sep. 23(Wed.) 2020, 10:00 JST (UTC+0900)

Speakers & Titles:

  1. Speaker: Chul-Moon Yoo (Nagoya Univ.)
    Title: Abundance of Primordial Black Holes in Peak Theory for an Arbitrary Power Spectrum (slide)
    ArXiv no.: 2008.02425

  2. Speaker: Hiromasa Nakatsuka (ICRR, Univ. of Tokyo)
    Title: Probing Extremely Light Axion-like Particles via CMB Polarization (slide)
    ArXiv no.: 2008.02473

  3. Speaker: Junsei Tokuda (Kobe Univ.)
    Title: Gravitational positivity bounds (slide)
    ArXiv no.: 2007.15009