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AOKI Katsuki
| Material Science Division | Assistant Professor |
| Physics |
Researcher information
■ Degree■ Field Of Study
■ Career
- Apr. 2026 - Present, Saitama University, Graduate School of Science and Engineering
- Jul. 2022 - Mar. 2026, Kyoto University, Yukawa Institute for Theoretical Physics
- Apr. 2022 - Jun. 2022, Kyoto University, Yukawa Institute for Theoretical Physics
- Apr. 2019 - Mar. 2022, Kyoto University, Yukawa Institute for Theoretical Physics
- Apr. 2018 - Mar. 2019, Waseda University, Faculty of Science and Engineering
- Apr. 2015 - Mar. 2018, Waseda University, Faculty of Science and Engineering
- Sep. 2014 - Mar. 2017, Waseda University, Graduate School of Advanced Science and Engineering
- Apr. 2013 - Sep. 2014, Waseda University, Graduate School of Advanced Science and Engineering
- Apr. 2009 - Mar. 2013, Waseda University, School of Advanced Science and Engineering
Performance information
■ Paper- Resumming scattering amplitudes for waveforms
Katsuki Aoki; Andrea Cristofoli
Journal of High Energy Physics, Apr. 2026, [Reviewed]
Scientific journal
DOI：https://doi.org/10.1007/JHEP04(2026)198
DOI ID：10.1007/JHEP04(2026)198, ORCID：213014481 - Effective field theory of coupled dark energy and dark matter
Katsuki Aoki; Jose Beltrán Jiménez; Masroor C. Pookkillath; Shinji Tsujikawa
Physical Review D, Feb. 2026, [Reviewed]
Scientific journal
DOI：https://doi.org/10.1103/5wsb-1vk6
DOI ID：10.1103/5wsb-1vk6, ORCID：206255367 - Effective field theory of chiral gravitational waves
Katsuki Aoki; Tomohiro Fujita; Ryodai Kawaguchi; Kazuki Yanagihara
Journal of Cosmology and Astroparticle Physics, Feb. 2026, [Reviewed]
Scientific journal
DOI：https://doi.org/10.1088/1475-7516/2026/02/018
DOI ID：10.1088/1475-7516/2026/02/018, ORCID：204947130 - Quantum effects for black holes with on-shell amplitudes
Katsuki Aoki; Andrea Cristofoli; Hyun Jeong; Matteo Sergola; Kaho Yoshimura
Journal of High Energy Physics, Dec. 2025, [Reviewed]
Scientific journal
DOI：https://doi.org/10.1007/JHEP12(2025)163
DOI ID：10.1007/JHEP12(2025)163, ORCID：200610977 - On-shell approach to black hole mergers
Katsuki Aoki; Andrea Cristofoli; Yu-tin Huang
Journal of High Energy Physics, Jan. 2025, [Reviewed]
Scientific journal
DOI：https://doi.org/10.1007/JHEP01(2025)066
DOI ID：10.1007/JHEP01(2025)066, ORCID：175813119 - Anomalous thresholds for the S-matrix of unstable particles
Katsuki Aoki; Yu-tin Huang
Journal of High Energy Physics, Sep. 2024, [Reviewed]
Scientific journal
DOI：https://doi.org/10.1007/JHEP09(2024)045
DOI ID：10.1007/JHEP09(2024)045, ORCID：167217104 - Cosmological perturbation theory in metric-affine gravity
Katsuki Aoki; Sebastian Bahamonde; Jorge Gigante Valcarcel; Mohammad Ali Gorji
Physical Review D, Jul. 2024, [Reviewed]
Scientific journal
DOI：https://doi.org/10.1103/PhysRevD.110.024017
DOI ID：10.1103/PhysRevD.110.024017, ORCID：163280139 - Gravitational positivity for phenomenologists: Dark gauge boson in the swampland
Katsuki Aoki; Toshifumi Noumi; Ryo Saito; Sota Sato; Satoshi Shirai; Junsei Tokuda; Masahito Yamazaki
Physical Review D, Volume：110, Number：1, Jul. 2024, [Reviewed]
The gravitational positivity bound gives quantitative “swampland” constraints on low-energy effective theories inside theories of quantum gravity. We give a comprehensive discussion of this bound for those interested in applications to phenomenological model building. We present a practical recipe for deriving the bound, and discuss subtleties relevant for realistic models. As an illustration, we study the positivity bound on the scattering of the massive gauge bosons in the Higgs/Stückelberg mechanism. Under certain assumptions on gravitational amplitudes at high energy, we obtain a lower bound mV≳ΛUV2/gMPl on the gauge boson mass mV, where g is the coupling constant of the gauge field, MPl is the reduced Planck mass and ΛUV is the ultraviolet cutoff of the effective field theory. This bound can strongly constrain new physics models involving a massive gauge boson. We also discuss how the bound depends on our high-energy assumptions.
Published by the American Physical Society 2024
American Physical Society (APS), Scientific journal
DOI：https://doi.org/10.1103/physrevd.110.016002
DOI ID：10.1103/physrevd.110.016002, ISSN：2470-0010, eISSN：2470-0029 - CMB spectrum in unified EFT of dark energy: scalar-tensor and vector-tensor theories
Katsuki Aoki; Mohammad Ali Gorji; Takashi Hiramatsu; Shinji Mukohyama; Masroor C. Pookkillath; Kazufumi Takahashi
Journal of Cosmology and Astroparticle Physics, Volume：2024, Number：07, First page：056, Last page：056, Jul. 2024, [Reviewed]
Abstract
We study the cosmic microwave background (CMB) radiation in the unified description of the effective field theory (EFT) of dark energy that accommodates both scalar-tensor and vector-tensor theories. The boundaries of different classes of theories are universally parameterised by a new EFT parameter αV characterising the vectorial nature of dark energy and a set of consistency relations associated with the global/local shift symmetry. After implementing the equations of motion in a Boltzmann code, as a demonstration, we compute the CMB power spectrum based on the wCDM background with the EFT parameterisation of perturbations and a concrete Horndeski/generalised Proca theory. We show that the vectorial nature generically prevents modifications of gravity in the CMB spectrum. On the other hand, while the shift symmetry is less significant in the perturbation equations unless the background is close to the ΛCDM, it requires that the effective equation of state of dark energy is in the phantom region w DE<-1. The latter is particularly interesting in light of the latest result of the DESI+CMB combination as the observational verification of w DE>-1 can rule out shift-symmetric theories including vector-tensor theories in one shot.
IOP Publishing, Scientific journal
DOI：https://doi.org/10.1088/1475-7516/2024/07/056
DOI ID：10.1088/1475-7516/2024/07/056, eISSN：1475-7516 - Exploring the spin of ultralight dark matter with gravitational wave detectors
Yusuke Manita; Hiroki Takeda; Katsuki Aoki; Tomohiro Fujita; Shinji Mukohyama
Physical Review D, Volume：109, Number：9, May 2024, [Reviewed]
We propose a novel method for distinguishing the spin of ultralight dark matter (ULDM) using interferometric gravitational wave detectors. ULDM can be a bosonic field of spin-0, 1, or 2, and each induces distinctive signatures in signals. We find that the finite-time traveling effect causes a dominant signal for spin-0 and spin-1 ULDM, but not for spin-2. By using overlap reduction functions (ORF) of multiple detectors, we can differentiate between the spins of ULDM. Furthermore, we point out that the current constraint on the coupling constant of spin-1 ULDM to baryons becomes 30 times weaker when the finite-time light-travel effect on the ORF is taken into account.
Published by the American Physical Society 2024
American Physical Society (APS), Scientific journal
DOI：https://doi.org/10.1103/physrevd.109.095012
DOI ID：10.1103/physrevd.109.095012, ISSN：2470-0010, eISSN：2470-0029 - Effective field theory of black hole perturbations in vector-tensor gravity
Katsuki Aoki; Mohammad Ali Gorji; Shinji Mukohyama; Kazufumi Takahashi; Vicharit Yingcharoenrat
Journal of Cosmology and Astroparticle Physics, Volume：2024, Number：03, First page：012, Last page：012, Mar. 2024, [Reviewed]
Abstract
We formulate the effective field theory (EFT) of vector-tensor gravity for perturbations around an arbitrary background with a timelike vector profile, which can be applied to study black hole perturbations. The vector profile spontaneously breaks both the time diffeomorphism and the U(1) symmetry, leaving their combination and the spatial diffeomorphism as the residual symmetries in the unitary gauge. We derive two sets of consistency relations which guarantee the residual symmetries of the EFT. Also, we provide the dictionary between our EFT coefficients and those of generalized Proca (GP) theories, which enables us to identify a simple subclass of the EFT that includes the GP theories as a special case. For this subclass, we consider the stealth Schwarzschild(-de Sitter) background solution with a constant temporal component of the vector field and study the decoupling limit of the longitudinal mode of the vector field, explicitly showing that the strong coupling problem arises due to vanishing sound speeds. This is in sharp contrast to the case of gauged ghost condensate, in which perturbations are weakly coupled thanks to certain higher-derivative terms, i.e., the scordatura terms. This implies that, in order to consistently describe this type of stealth solutions within the EFT, the scordatura terms must necessarily be taken into account in addition to those already included in the simple subclass.
IOP Publishing, Scientific journal
DOI：https://doi.org/10.1088/1475-7516/2024/03/012
DOI ID：10.1088/1475-7516/2024/03/012, eISSN：1475-7516 - Cosmology and the classical limit of the S-matrix
Aoki, K.; Cristofoli, A.
Journal of High Energy Physics, Volume：2024, Number：6, 2024, [Reviewed]
Scientific journal
DOI：https://doi.org/10.1007/JHEP06(2024)032
DOI ID：10.1007/JHEP06(2024)032, ISSN：1029-8479, ORCID：186580793, SCOPUS ID：85195552692 - Coupled vector Gauss-Bonnet theories and hairy black holes
Aoki, K.; Tsujikawa, S.
Physics Letters Section B Nuclear Elementary Particle and High Energy Physics, Volume：843, First page：138022, Last page：138022, Aug. 2023, [Reviewed]
Elsevier {BV}, Scientific journal
DOI：https://doi.org/10.1016/j.physletb.2023.138022
DOI ID：10.1016/j.physletb.2023.138022, ISSN：0370-2693, ORCID：186580826, SCOPUS ID：85163858907 - Spin-2 dark matter from an anisotropic universe in bigravity
Yusuke Manita; Katsuki Aoki; Tomohiro Fujita; Shinji Mukohyama
Physical Review D, Volume：107, Number：10, May 2023, [Reviewed]
American Physical Society ({APS}), Scientific journal
DOI：https://doi.org/10.1103/physrevd.107.104007
DOI ID：10.1103/physrevd.107.104007, ISSN：2470-0010, eISSN：2470-0029, ORCID：139248948 - Some disquisitions on cosmological 2-form dualities
Aoki, K.; Beltr{\'a}n Jim{\'e}nez, J.; Figueruelo, D.
Journal of Cosmology and Astroparticle Physics, Volume：2023, Number：4, First page：059, Last page：059, Apr. 2023, [Reviewed]
{IOP} Publishing, Scientific journal
DOI：https://doi.org/10.1088/1475-7516/2023/04/059
DOI ID：10.1088/1475-7516/2023/04/059, ISSN：1475-7516, ORCID：186580799, SCOPUS ID：85153894443 - Cosmological gravity probes: Connecting recent theoretical developments to forthcoming observations
Shun Arai; Katsuki Aoki; Yuji Chinone; Rampei Kimura; Tsutomu Kobayashi; Hironao Miyatake; Daisuke Yamauchi; Shuichiro Yokoyama; Kazuyuki Akitsu; Takashi Hiramatsu; Shin’ichi Hirano; Ryotaro Kase; Taishi Katsuragawa; Yosuke Kobayashi; Toshiya Namikawa; Takahiro Nishimichi; Teppei Okumura; Maresuke Shiraishi; Masato Shirasaki; Tomomi Sunayama; Kazufumi Takahashi; Atsushi Taruya; Junsei Tokuda
Progress of Theoretical and Experimental Physics, Volume：2023, Number：7, Apr. 2023, [Reviewed]
Oxford University Press ({OUP}), Scientific journal
DOI：https://doi.org/10.1093/ptep/ptad052
Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85165075685&origin=inward
Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85165075685&origin=inward
DOI ID：10.1093/ptep/ptad052, ISSN：2050-3911, eISSN：2050-3911, ORCID：139249009, SCOPUS ID：85165075685 - Unitarity and unstable-particle scattering amplitudes
Aoki, K.
Physical Review D, Volume：107, Number：6, Mar. 2023, [Reviewed]
Scientific journal
DOI：https://doi.org/10.1103/PhysRevD.107.065017
DOI ID：10.1103/PhysRevD.107.065017, ISSN：2470-0010, ORCID：186580800, SCOPUS ID：85151267544 - Highly compact Proca stars with quartic self-interactions
Aoki, K.; Minamitsuji, M.
Physical Review D, Volume：107, Number：4, 2023, [Reviewed]
American Physical Society ({APS}), Scientific journal
DOI：https://doi.org/10.1103/PhysRevD.107.044045
DOI ID：10.1103/PhysRevD.107.044045, ISSN：2470-0010, ORCID：186580817, SCOPUS ID：85149574215 - Resolving the pathologies of self-interacting Proca fields: A case study of Proca stars
Aoki, K.; Minamitsuji, M.
Physical Review D, Volume：106, Number：8, Oct. 2022, [Reviewed]
Scientific journal
DOI：https://doi.org/10.1103/PhysRevD.106.084022
DOI ID：10.1103/PhysRevD.106.084022, ISSN：2470-0010, ORCID：186580746, SCOPUS ID：85140269021 - Effective field theory of gravitating continuum: solids, fluids, and aether unified
Katsuki Aoki; Mohammad Ali Gorji; Shinji Mukohyama; Kazufumi Takahashi
Journal of Cosmology and Astroparticle Physics, Volume：2022, Number：08, First page：072, Last page：072, Aug. 2022, [Reviewed]
Abstract
We investigate the relativistic effective field theory (EFT) describing a non-dissipative gravitating continuum. In addition to ordinary continua, namely solids and fluids, we find an extraordinary more symmetric continuum, aether. In particular, the symmetry of the aether concludes that a homogeneous and isotropic state behaves like a cosmological constant. We formulate the EFT in the unitary/comoving gauge in which the dynamical degrees of freedom of the continuum (phonons) are eaten by the spacetime metric. This gauge choice, which is interpreted as the Lagrangian description in hydrodynamics, offers a neat geometrical understanding of continua. We examine a thread-based spacetime decomposition with respect to the four-velocity of the continuum which is different from the foliation-based Arnowitt-Deser-Misner one. Our thread-based decomposition respects the symmetries of the continua and, therefore, makes it possible to systematically find invariant building blocks of the EFT for each continuum even at higher orders in the derivative expansion. We also discuss the linear dynamics of the system and show that both gravitons and phonons acquire “masses” in a gravitating background.
IOP Publishing, Scientific journal
DOI：https://doi.org/10.1088/1475-7516/2022/08/072
DOI ID：10.1088/1475-7516/2022/08/072, ISSN：1475-7516, eISSN：1475-7516, ORCID：118405295 - The effective field theory of vector-tensor theories
Katsuki Aoki; Mohammad Ali Gorji; Shinji Mukohyama; Kazufumi Takahashi
Journal of Cosmology and Astroparticle Physics, Volume：2022, Number：01, First page：059, Last page：059, Jan. 2022, [Reviewed]
Abstract
We investigate a systematic formulation of vector-tensor theories based on the effective field theory (EFT) approach. The input of our EFT is that the spacetime symmetry is spontaneously broken by the existence of a preferred timelike direction in accordance with the cosmological principle. After clarifying the difference of the symmetry breaking pattern from the conventional EFT of inflation/dark energy, we find an EFT description of vector-tensor theories around the cosmological background. This approach not only serves as a unified description of vector-tensor theories but also highlights universal differences between the scalar-tensor theories and the vector-tensor theories. The theories having different symmetry breaking patterns are distinguished by a phenomenological function and consistency relations between the EFT coefficients. We study the linear cosmological perturbations within our EFT framework and discuss the characteristic properties of the vector-tensor theories in the context of dark energy. In particular, we compute the effective gravitational coupling and the slip parameter for the matter density contrast in terms of the EFT coefficients.
IOP Publishing, Scientific journal
DOI：https://doi.org/10.1088/1475-7516/2022/01/059
DOI ID：10.1088/1475-7516/2022/01/059, ISSN：1475-7516, eISSN：1475-7516, ORCID：110057546 - Shift-symmetric ����(��) multi-Galileon
Katsuki Aoki; Yusuke Manita; Shinji Mukohyama
Journal of Cosmology and Astroparticle Physics, Volume：2021, Number：12, First page：045, Last page：045, Dec. 2021, [Reviewed]
Abstract
A Poincarè invariant, local scalar field theory in which the Lagrangian and the equation of motion contain only up to second-order derivatives of the fields is called generalized Galileon. The covariant version of it in four dimensions is called Horndeski theory, and has been vigorously studied in applications to inflation and dark energy. In this paper, we study a class of multi-field extensions of the generalized Galileon theory. By imposing shift and SO(N) symmetries on all the currently known multi-Galileon terms in general dimensions, we find that the structure of the Lagrangian is uniquely determined and parameterized by a series of coupling constants. We also study tensor perturbation in the shift-symmetric SO(3) multi-Galileon theory in four dimensions. The tensor perturbations can obtain a mass term stemming from the same symmetry breaking pattern as the solid inflation. We also find that the shift-symmetric SO(3) multi-Galileon theory gives rise to new cubic interactions of the tensor modes, suggesting the existence of a new type of tensor primordial non-Gaussianity.
IOP Publishing, Scientific journal
DOI：https://doi.org/10.1088/1475-7516/2021/12/045
DOI ID：10.1088/1475-7516/2021/12/045, ISSN：1475-7516, eISSN：1475-7516, ORCID：110057511 - Positivity vs. Lorentz-violation: an explicit example
Katsuki Aoki; Shinji Mukohyama; Ryo Namba
Journal of Cosmology and Astroparticle Physics, Volume：2021, Number：10, First page：079, Last page：079, Oct. 2021, [Reviewed]
IOP Publishing, Scientific journal
DOI：https://doi.org/10.1088/1475-7516/2021/10/079
DOI ID：10.1088/1475-7516/2021/10/079, ISSN：1475-7516, eISSN：1475-7516, ORCID：110057515 - Is the Standard Model in the Swampland? Consistency Requirements from Gravitational Scattering
Aoki, K.; Loc, T.Q.; Noumi, T.; Tokuda, J.
Physical Review Letters, Volume：127, Number：9, Aug. 2021, [Reviewed]
Scientific journal
DOI：https://doi.org/10.1103/PhysRevLett.127.091602
DOI ID：10.1103/PhysRevLett.127.091602, ISSN：0031-9007, ORCID：186580790, SCOPUS ID：85114143308 - Erratum: Cosmology and gravitational waves in consistent D→ 4 Einstein-Gauss-Bonnet gravity (Journal of Cosmology and Astroparticle Physics (2020) 9 (14) DOI: 10.1103/PhysRevLett.118.221101)
Katsuki Aoki; Mohammad Ali Gorji; Shinji Mukohyama
Journal of Cosmology and Astroparticle Physics, Volume：2021, Number：5, May 2021, [Reviewed]
IOP Publishing Ltd, English, Scientific journal
DOI：https://doi.org/10.1088/1475-7516/2021/05/E01
DOI ID：10.1088/1475-7516/2021/05/E01, ISSN：1475-7516, SCOPUS ID：85107290912 - Non-uniqueness of massless transverse-traceless graviton
Katsuki Aoki; Francesco Di Filippo; Shinji Mukohyama
Journal of Cosmology and Astroparticle Physics, Volume：2021, Number：05, First page：071, Last page：071, May 2021, [Reviewed]
Abstract
We study a theory of minimally modified gravity called cuscuton/VCDM that propagates only two gravitational degrees of freedom. Despite being apparently different from general relativity (GR), it is in principle possible that this theory might be obtained via a field redefinition starting from the GR action. This would make the vacuum theory equivalent to GR and the theory would differ from GR only in the presence of matter. In this paper, studying the dispersion relation of gravitational waves and the dynamics of the Bianchi-I universe, we prove that such a field redefinition does not exist and that the theory differs from GR already in vacuum.
IOP Publishing, Scientific journal
DOI：https://doi.org/10.1088/1475-7516/2021/05/071
DOI ID：10.1088/1475-7516/2021/05/071, ISSN：1475-7516, eISSN：1475-7516, ORCID：96915832 - Inflationary gravitational waves in consistent D → 4 Einstein-Gauss-Bonnet gravity
Katsuki Aoki; Mohammad Ali Gorji; Shuntaro Mizuno; Shinji Mukohyama
Journal of Cosmology and Astroparticle Physics, Volume：2021, Number：01, First page：054, Last page：054, Jan. 2021, [Reviewed]
IOP Publishing, Scientific journal
DOI：https://doi.org/10.1088/1475-7516/2021/01/054
DOI ID：10.1088/1475-7516/2021/01/054, ISSN：1475-7516, eISSN：1475-7516, ORCID：91310990 - Nonlinearly ghost-free higher curvature gravity
Aoki, K.
Physical Review D, Volume：102, Number：12, Dec. 2020, [Reviewed]
Scientific journal
DOI：https://doi.org/10.1103/PhysRevD.102.124049
DOI ID：10.1103/PhysRevD.102.124049, ISSN：2470-0010, ORCID：186580742, SCOPUS ID：85099157912 - Gravitational positivity bounds
Tokuda, J.; Aoki, K.; Hirano, S.
Journal of High Energy Physics, Volume：2020, Number：11, Nov. 2020, [Reviewed]
Springer Science and Business Media {LLC}, Scientific journal
DOI：https://doi.org/10.1007/JHEP11(2020)054
DOI ID：10.1007/JHEP11(2020)054, ISSN：1029-8479, ORCID：186580777, SCOPUS ID：85095954567 - Ghost from constraints: a generalization of Ostrogradsky theorem
Katsuki Aoki; Hayato Motohashi
Journal of Cosmology and Astroparticle Physics, Volume：2020, Number：08, First page：026, Last page：026, Aug. 2020, [Reviewed]
IOP Publishing, Scientific journal
DOI：https://doi.org/10.1088/1475-7516/2020/08/026
DOI ID：10.1088/1475-7516/2020/08/026, ISSN：1475-7516, eISSN：1475-7516, ORCID：81579904 - Minimally modified gravity fitting Planck data better than Λ CDM
Aoki, K.; De Felice, A.; Mukohyama, S.; Noui, K.; Oliosi, M.; C. Pookkillath, M.
European Physical Journal C, Volume：80, Number：8, May 2020, [Reviewed]
Springer Science and Business Media {LLC}, English, Scientific journal
DOI：https://doi.org/10.1140/epjc/s10052-020-8291-1
DOI ID：10.1140/epjc/s10052-020-8291-1, ISSN：1434-6044, ORCID：186580801, SCOPUS ID：85089105434 - Cosmology and gravitational waves in consistent D 4 Einstein-Gauss-Bonnet gravity
Aoki, K.; Gorji, M.A.; Mukohyama, S.
Journal of Cosmology and Astroparticle Physics, Volume：2020, Number：9, First page：014, Last page：014, May 2020, [Reviewed]
{IOP} Publishing, English, Scientific journal
DOI：https://doi.org/10.1088/1475-7516/2020/09/014
DOI ID：10.1088/1475-7516/2020/09/014, ISSN：1475-7516, ORCID：186580760, SCOPUS ID：85093533260 - A consistent theory of D → 4 Einstein-Gauss-Bonnet gravity
Aoki, K.; Gorji, M.A.; Mukohyama, S.
Physics Letters Section B Nuclear Elementary Particle and High Energy Physics, Volume：810, First page：135843, Last page：135843, May 2020, [Reviewed]
Elsevier {BV}, English, Scientific journal
DOI：https://doi.org/10.1016/j.physletb.2020.135843
DOI ID：10.1016/j.physletb.2020.135843, ISSN：0370-2693, ORCID：186580809, SCOPUS ID：85092217544 - Consistent inflationary cosmology from quadratic gravity with dynamical torsion
Aoki, K.; Mukohyama, S.
Journal of Cosmology and Astroparticle Physics, Volume：2020, Number：6, Mar. 2020, [Reviewed]
English, Scientific journal
DOI：https://doi.org/10.1088/1475-7516/2020/06/004
DOI ID：10.1088/1475-7516/2020/06/004, ISSN：1475-7516, ORCID：186580807, SCOPUS ID：85088692053 - Ghostfree quadratic curvature theories with massive spin-2 and spin-0 particles
Aoki, K.; Mukohyama, S.
Physical Review D, Volume：100, Number：6, Sep. 2019, [Reviewed]
American Physical Society ({APS}), Scientific journal
DOI：https://doi.org/10.1103/PhysRevD.100.064061
DOI ID：10.1103/PhysRevD.100.064061, ISSN：2470-0010, ORCID：186580808, SCOPUS ID：85073200527 - Scalar-metric-affine theories: Can we get ghost-free theories from symmetry?
Aoki, K.; Shimada, K.
Physical Review D, Volume：100, Number：4, Aug. 2019, [Reviewed]
American Physical Society ({APS}), Scientific journal
DOI：https://doi.org/10.1103/PhysRevD.100.044037
DOI ID：10.1103/PhysRevD.100.044037, ISSN：2470-0010, ORCID：186580802, SCOPUS ID：85072230204 - Metric-affine gravity and inflation
Keigo Shimada; Katsuki Aoki; Kei-ichi Maeda
Physical Review D, Volume：99, Number：10, May 2019, [Reviewed]
American Physical Society ({APS}), Scientific journal
DOI：https://doi.org/10.1103/physrevd.99.104020
DOI ID：10.1103/physrevd.99.104020, ISSN：2470-0010, eISSN：2470-0029, ORCID：64168542 - Phenomenology in type-I minimally modified gravity
Aoki, K.; Felice, A.D.; Lin, C.; Mukohyama, S.; Oliosi, M.
Journal of Cosmology and Astroparticle Physics, Volume：2019, Number：1, First page：017, Jan. 2019, [Reviewed]
{IOP} Publishing, Scientific journal
DOI：https://doi.org/10.1088/1475-7516/2019/01/017
DOI ID：10.1088/1475-7516/2019/01/017, ISSN：1475-7516, ORCID：186580791, SCOPUS ID：85062290865 - Novel matter coupling in general relativity via canonical transformation
Aoki, K.; Lin, C.; Mukohyama, S.
Physical Review D, Volume：98, Number：4, Aug. 2018, [Reviewed]
American Physical Society ({APS}), Scientific journal
DOI：https://doi.org/10.1103/PhysRevD.98.044022
DOI ID：10.1103/PhysRevD.98.044022, ISSN：2470-0010, ORCID：186580754, SCOPUS ID：85052629703 - Galileon and generalized Galileon with projective invariance in a metric-affine formalism
Aoki, K.; Shimada, K.
Physical Review D, Volume：98, Number：4, Aug. 2018, [Reviewed]
American Physical Society ({APS}), Scientific journal
DOI：https://doi.org/10.1103/PhysRevD.98.044038
DOI ID：10.1103/PhysRevD.98.044038, ISSN：2470-0010, ORCID：186580819, SCOPUS ID：85052622389 - Massive graviton geons
Katsuki Aoki; Kei-Ichi Maeda; Yosuke Misonoh; Hirotada Okawa
Physical Review D, Volume：97, Number：4, Feb. 2018, [Reviewed]
American Physical Society, English, Scientific journal
DOI：https://doi.org/10.1103/PhysRevD.97.044005
Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85043707342&origin=inward
Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85043707342&origin=inward
DOI ID：10.1103/PhysRevD.97.044005, ISSN：2470-0029, eISSN：2470-0029, ORCID：41478327, SCOPUS ID：85043707342 - Condensate of massive graviton and dark matter
Katsuki Aoki; Kei-Ichi Maeda
Physical Review D, Volume：97, Number：4, Feb. 2018, [Reviewed]
American Physical Society, English, Scientific journal
DOI：https://doi.org/10.1103/PhysRevD.97.044002
DOI ID：10.1103/PhysRevD.97.044002, ISSN：2470-0029, ORCID：41478388, SCOPUS ID：85043704123 - Massive graviton dark matter with environment dependent mass: A natural explanation of the dark matter-baryon ratio
Katsuki Aoki; Shinji Mukohyama
PHYSICAL REVIEW D, Volume：96, Number：10, Nov. 2017, [Reviewed]
English, Scientific journal
DOI：https://doi.org/10.1103/PhysRevD.96.104039
DOI ID：10.1103/PhysRevD.96.104039, ISSN：2470-0010, eISSN：2470-0029, ORCID：41478403, Web of Science ID：WOS:000416026700003 - Cosmological and astrophysical Vainshtein mechanism in bigravity
Katsuki Aoki; Kei-ichi Maeda; Makoto Tanabe; Ryo Namba
The Fourteenth Marcel Grossmann Meeting, Nov. 2017, [Reviewed]
WORLD} {SCIENTIFIC
DOI：https://doi.org/10.1142/9789813226609_0134
DOI ID：10.1142/9789813226609_0134, ORCID：40033232 - Vainshtein mechanism in massive gravity nonlinear sigma models
Katsuki Aoki; Shuntaro Mizuno
PHYSICAL REVIEW D, Volume：94, Number：6, Sep. 2016, [Reviewed]
English, Scientific journal
DOI：https://doi.org/10.1103/PhysRevD.94.064054
DOI ID：10.1103/PhysRevD.94.064054, ISSN：2470-0010, eISSN：2470-0029, ORCID：36027392, Web of Science ID：WOS:000383874800005 - Massive gravitons as dark matter and gravitational waves
Katsuki Aoki; Shinji Mukohyama
PHYSICAL REVIEW D, Volume：94, Number：2, Jul. 2016, [Reviewed]
English, Scientific journal
DOI：https://doi.org/10.1103/PhysRevD.94.024001
DOI ID：10.1103/PhysRevD.94.024001, ISSN：2470-0010, eISSN：2470-0029, ORCID：36027405, Web of Science ID：WOS:000378910600001 - Relativistic stars in bigravity theory
Katsuki Aoki; Kei-ichi Maeda; Makoto Tanabe
PHYSICAL REVIEW D, Volume：93, Number：6, Mar. 2016, [Reviewed]
English, Scientific journal
DOI：https://doi.org/10.1103/PhysRevD.93.064054
DOI ID：10.1103/PhysRevD.93.064054, ISSN：2470-0010, eISSN：2470-0029, ORCID：36027386, Web of Science ID：WOS:000372722300006 - Stability of the early universe in bigravity theory
Katsuki Aoki; Kei-Ichi Maeda; Ryo Namba
Physical Review D - Particles, Fields, Gravitation and Cosmology, Volume：92, Number：4, Aug. 2015, [Reviewed]
American Physical Society, English, Scientific journal
DOI：https://doi.org/10.1103/PhysRevD.92.044054
DOI ID：10.1103/PhysRevD.92.044054, ISSN：1550-2368, SCOPUS ID：84940825779 - Stability of the early universe in bigravity theory
Katsuki Aoki; Kei-ichi Maeda; Ryo Namba
PHYSICAL REVIEW D, Volume：92, Number：4, Aug. 2015, [Reviewed]
English, Scientific journal
DOI：https://doi.org/10.1103/PhysRevD.92.044054
DOI ID：10.1103/PhysRevD.92.044054, ISSN：2470-0010, eISSN：2470-0029, ORCID：36027401, Web of Science ID：WOS:000360285800004 - Dark matter in ghost-free bigravity theory: From a galaxy scale to the universe
Katsuki Aoki; Kei-ichi Maeda
PHYSICAL REVIEW D, Volume：90, Number：12, Dec. 2014, [Reviewed]
English, Scientific journal
DOI：https://doi.org/10.1103/PhysRevD.90.124089
DOI ID：10.1103/PhysRevD.90.124089, ISSN：2470-0010, eISSN：2470-0029, ORCID：36027379, Web of Science ID：WOS:000347194400017 - Cosmology in ghost-free bigravity theory with twin matter fluids: The origin of dark matter
Katsuki Aoki; Kei-ichi Maeda
PHYSICAL REVIEW D, Volume：89, Number：6, Mar. 2014, [Reviewed]
English, Scientific journal
DOI：https://doi.org/10.1103/PhysRevD.89.064051
DOI ID：10.1103/PhysRevD.89.064051, ISSN：2470-0010, eISSN：2470-0029, ORCID：36027398, Web of Science ID：WOS:000333111200007
- 散乱振幅からブラックホールへ
青木勝輝
Feb. 2026, [Invited], [Domestic conference]
Japanese, Invited oral presentation - From Scattering Amplitudes to Black Holes
青木勝輝
Feb. 2026, [Invited], [International conference]
English, Invited oral presentation - EFTs across the Universe
青木勝輝
Jan. 2026, [Invited], [International conference]
English, Invited oral presentation - From Scattering Amplitudes to Black Holes
青木勝輝
Jan. 2026, [Invited]
English, Public discourse - Quantum Effects for Black Holes with On-Shell Amplitudes
青木勝輝
Nov. 2025, [Invited]
Japanese, Public discourse - From Scattering Amplitudes to Black Holes
青木勝輝
Oct. 2025, [Invited]
English, Public discourse - On-shell Approach to Black Hole Mergers
青木勝輝
Oct. 2025, [International conference]
English, Oral presentation - From Scattering Amplitudes to Black Holes
青木勝輝
Oct. 2025, [Invited], [International conference]
English, Oral presentation - From Scattering Amplitudes to Gravity, and to Waves
青木勝輝
Sep. 2025, [Invited], [International conference]
English, Invited oral presentation - On-shell Approach to Black Hole Mergers
青木勝輝
Sep. 2025, [Domestic conference]
Japanese, Oral presentation - On-shell Approach to Black Hole Mergers
青木勝輝
Jul. 2025, [Domestic conference]
Japanese, Oral presentation - On-shell Approach to Black Hole Mergers (and Hawking Radiation)
青木勝輝
Jul. 2025, [Invited]
Japanese, Public discourse - On-shell Approach to Black Hole Mergers (and Hawking Radiation)
青木勝輝
Jul. 2025, [Domestic conference]
Japanese, Oral presentation - On-shell Approach to Black Hole Mergers
青木勝輝
Apr. 2025, [Invited], [International conference]
English, Invited oral presentation - On-shell Approach to Black Hole Mergers
青木勝輝
Dec. 2024, [Invited]
English, Public discourse - On-shell Approach to Black Hole Mergers
青木勝輝
Dec. 2024, [Invited], [International conference]
English, Invited oral presentation - On-shell Approach to Black Hole Mergers
青木勝輝
Dec. 2024, [International conference]
English, Oral presentation - Unified EFT of Dark Energy
青木勝輝
Oct. 2024, [Invited]
Invited oral presentation - Cosmology and the classical limit of the S-matrix
青木勝輝
Sep. 2024, [Domestic conference]
Japanese, Oral presentation - Anomalous Thresholds for the S-matrix of Unstable Particles
青木勝輝
Aug. 2024, [Domestic conference]
Japanese, Oral presentation - Anomalous Thresholds for the S-matrix of Unstable Particles
青木勝輝
Aug. 2024, [Invited], [International conference]
English, Invited oral presentation - Unified EFT of Dark Energy
青木勝輝
Jun. 2024, [Invited], [International conference]
English, Invited oral presentation - Unified EFT of Dark Energy
青木勝輝
Jun. 2024, [Invited]
English, Public discourse - Analytic S-matrix of Unstable Particles
青木勝輝
Jan. 2024, [Invited], [International conference]
English, Invited oral presentation - Towards S-matrix theory of unstable particles
青木勝輝
Dec. 2023, [Invited]
Japanese, Public discourse - Is a scalar field everything about dark sectors/modified gravity?
青木勝輝
Dec. 2023, [Invited], [Domestic conference]
Japanese, Invited oral presentation - Towards bootstrapping quantum gravity: Unitarity of heavy particles
青木勝輝
Nov. 2023, [International conference]
English, Oral presentation - Towards quantum gravity constraints from S-matrix
青木勝輝
Oct. 2023, [Invited], [International conference]
English, Invited oral presentation - Towards S-matrix theory of unstable particles
青木勝輝
Oct. 2023, [Invited]
English, Public discourse - Towards quantum gravity constraints from S-matrix
青木勝輝
Sep. 2023, [Invited], [International conference]
English, Invited oral presentation - The Effective Field Theory of Vector-Tensor Theories
青木勝輝
Sep. 2023, [International conference]
English, Oral presentation - 不安定粒子の散乱振幅と正値性
青木勝輝
Aug. 2023, [Domestic conference]
Japanese, Oral presentation - Towards S-matrix theory of unstable particles
青木勝輝
Aug. 2023, [Domestic conference]
Japanese, Oral presentation - Effective Field Theory Approaches to Cosmology
青木勝輝
Jun. 2023, [Invited], [International conference]
English, Invited oral presentation - Towards S-matrix theory of unstable particles
青木勝輝
May 2023, [Invited]
English, Public discourse - Massive graviton as dark matter
青木勝輝
Mar. 2023, [Invited]
English, Public discourse - Towards S-matrix theory of unstable particles
青木勝輝
Mar. 2023, [Invited]
English, Public discourse - Effective Field Theory Approaches to Cosmology
青木勝輝
Mar. 2023, [Invited], [Domestic conference]
Japanese, Invited oral presentation - Gravitational Positivity Bounds
青木勝輝
Feb. 2023, [Invited]
English, Public discourse - Positivity beyond tree level
青木勝輝
Jan. 2023, [Invited], [International conference]
English, Invited oral presentation - The Effective Field Theory of Vector-Tensor Theories
青木勝輝
Nov. 2022, [Invited], [International conference]
English, Invited oral presentation - The Effective Field Theory of Vector-Tensor Theories
青木勝輝
Oct. 2022, [International conference]
English, Oral presentation - Effective Field Theory of Gravitating Continuum: Solids, Fluids, and Aether Unified
青木勝輝
Sep. 2022, [Domestic conference]
Japanese, Oral presentation - Gravitational Positivity Bounds
青木勝輝
Apr. 2022, [Invited]
Japanese, Public discourse - Gravitational Positivity Bounds
青木勝輝
Mar. 2022, [Invited]
English, Public discourse - The Effective Field Theory of Vector-Tensor Theories
青木勝輝
Mar. 2022, [Domestic conference]
Japanese, Oral presentation - The Effective Field Theory of Vector-Tensor Theories
青木勝輝
Mar. 2022, [Invited], [International conference]
English, Invited oral presentation - The Effective Field Theory of Vector-Tensor Theories
青木勝輝
Feb. 2022
Japanese, Public discourse - Positivity vs. Lorentz-violation
青木勝輝
Dec. 2021, [International conference]
English, Oral presentation - Is the Standard Model in the Swampland? Consistency Requirement from Gravitational Scattering
青木勝輝
Dec. 2021, [Invited]
English, Public discourse - Is the Standard Model in the Swampland? Consistency Requirement from Gravitational Scattering
青木勝輝
Nov. 2021, [Invited]
English, Public discourse - Positivity vs. Lorentz-violation
青木勝輝
Oct. 2021, [Invited], [International conference]
English, Oral presentation - UV consistency of gravitational and cosmological EFTs
青木勝輝
Oct. 2021, [Invited], [International conference]
English, Invited oral presentation - Is the Standard Model in the Swampland?
青木勝輝
Sep. 2021, [Domestic conference]
Japanese, Oral presentation - Positivity Bounds on Standard Model and General Relativity
青木勝輝
Sep. 2021, [Domestic conference]
Japanese, Oral presentation - Is the Standard Model in the Swampland?
青木勝輝
Aug. 2021, [International conference]
English, Oral presentation - Is the Standard Model in the Swampland?
青木勝輝
Jul. 2021, [Invited]
English, Public discourse - A consistent theory of four-dimensional Einstein-Gauss-Bonnet gravity: theory and cosmology
青木勝輝
Jul. 2021, [Invited]
English, Public discourse - Nonlinearly ghost-free higher curvature gravity
青木勝輝
Jul. 2021, [International conference]
English, Oral presentation - Is the Standard Model in the Swampland?
青木勝輝
May 2021, [Invited]
English, Public discourse - Non-linearly ghost-free higher curvature gravity
青木勝輝
Mar. 2021
English, Public discourse - Non-linearly ghost-free higher curvature gravity
青木勝輝
Jan. 2021, [Invited]
English, Public discourse - Non-linearly ghost-free higher curvature gravity
青木勝輝
Nov. 2020, [International conference]
English, Oral presentation - Gravitational Positivity Bounds
青木勝輝
Sep. 2020, [Invited]
English, Public discourse - Consistent inflationary cosmology from quadratic gravity with dynamical torsion
青木勝輝
Sep. 2020, [Domestic conference]
Japanese, Oral presentation - Quadratic Curvature Theory in Riemann-Cartan Geometry: Theory and Application to Cosmology
青木勝輝
Jan. 2020
English, Public discourse - Ghostfree quadratic curvature theory with massive spin-2 and spin-0 particles
青木勝輝
Dec. 2019, [Invited], [International conference]
English, Invited oral presentation - Ghostfree quadratic curvature theory with massive spin-2 and spin-0 particles
青木勝輝
Nov. 2019, [International conference]
English, Poster presentation - 計量アフィン形式におけるスカラーテンソル理論と射影対称性
青木勝輝
Sep. 2019, [Domestic conference]
Japanese, Oral presentation - Quadratic curvature theory with non-ghost massive spin-2 and massive spin-0 particles
青木勝輝
Sep. 2019
Japanese, Public discourse - Quadratic curvature theory with a non-ghost massive spin-2 particle in Riemann-Cartan geometry
青木勝輝
Sep. 2019, [International conference]
English, Oral presentation - Scalar-tensor theories beyond Riemannian
青木勝輝
Jul. 2019, [International conference]
English, Oral presentation - Ghost-free scalar-tensor theories in metric-affine formalism
青木勝輝
Nov. 2018, [International conference]
Bengali, Oral presentation - Novel matter coupling in general relativity via canonical transformation
青木勝輝
Sep. 2018, [Domestic conference]
Japanese, Oral presentation - Galileon and generalized Galileon with projective invariance in metric-affine formalism
青木勝輝
Aug. 2018, [International conference]
English, Oral presentation - Scalar-tensor theories in metric-affine formalism
青木勝輝
Aug. 2018, [International conference]
Bengali, Oral presentation - Massive Graviton Geons
青木勝輝
Mar. 2018, [Domestic conference]
Japanese, Oral presentation - On canonical transformation of GR and minimal modified gravity theories
青木勝輝
Mar. 2018
English, Public discourse - Massive Graviton Geons: self-gravitating massive gravitational waves
青木勝輝
Mar. 2018, [Domestic conference]
Japanese, Oral presentation - Massive Graviton Geons: self-gravitating massive gravitational waves
青木勝輝
Feb. 2018, [International conference]
English, Oral presentation - Massive Gravitons as Dark Matter
青木勝輝
Dec. 2017, [International conference]
English, Oral presentation - Massive gravitons as dark matter
青木勝輝
Dec. 2017, [Invited]
Japanese, Public discourse - Massive Graviton Geons: self-gravitating massive gravitational waves
青木勝輝
Oct. 2017, [Invited]
English, Public discourse - 質量をもった重力子の凝縮とダークマター
青木勝輝
Sep. 2017, [Domestic conference]
Japanese, Oral presentation - Massive Gravitons and Dark Matter
青木勝輝
Aug. 2017, [International conference]
English, Oral presentation - Massive gravitons as dark matter and gravitational waves
青木勝輝
Nov. 2016, [Invited]
English, Public discourse - Vainshtein mechanism in massive gravity nonlinear sigma models
青木勝輝
Oct. 2016, [International conference]
English, Oral presentation - Bigravitons as dark matter and gravitational waves
青木勝輝
Sep. 2016, [Domestic conference]
Japanese, Oral presentation - Bigravitons as dark matter and gravitational waves
Jul. 2016, [International conference]
English, Oral presentation - Bigravitons as dark matter and gravitational waves
青木勝輝
Jun. 2016, [Invited]
English, Public discourse - Stability of the Early Universe in Bigravity Theory
青木勝輝
Jan. 2016
Japanese, Public discourse - Relativistic stars in the bigravity theory
青木勝輝
Dec. 2015, [International conference]
English, Oral presentation - Cosmology and Astrophysics in the Bigravity Theory
青木勝輝
Nov. 2015, [Invited]
English, Public discourse - Cosmology and Astrophysics in the Bigravity Theory
青木勝輝
Nov. 2015, [Invited]
English, Public discourse - Cosmological and Astrophysical Vainshtein mechanism in bigravity
青木勝輝
Sep. 2015, [International conference]
English, Oral presentation - Cosmological and Astrophysical Vainshtein mechanism in bigravity
青木勝輝
Aug. 2015, [International conference]
English, Oral presentation - Stability of the Early Universe in Bigravity Theory
青木勝輝
Jul. 2015, [Invited]
Japanese, Public discourse - Time-dependent screening and stability around FLRW background in bigravity
青木勝輝
Mar. 2015, [Domestic conference]
Japanese, Oral presentation - Dark matter in ghost-free bigravity theory
青木勝輝
Nov. 2014, [International conference]
English, Oral presentation - The origin of dark components in ghost-free bigravity theory
青木勝輝
Jul. 2014
English, Public discourse - Bigravity理論とダークマター問題への応用
青木勝輝
Mar. 2014, [Domestic conference]
Japanese, Oral presentation - Cosmology in ghost-free bigravity theory with twin matter fluid
青木勝輝
Nov. 2013, [International conference]
English, Oral presentation - bigravity 理論に基づく宇宙論とダークエネルギー問題,
青木勝輝
Sep. 2013, [Domestic conference]
Japanese, Oral presentation
■ Research projects
- Study on gravity and cosmology with EFT and S-matrix methods
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Early-Career Scientists, Apr. 2024 - Mar. 2028
Kyoto University
Grant amount(Total)：4550000, Direct funding：3500000, Indirect funding：1050000
Grant number：24K17046 - 重力波と散乱振幅
01 Oct. 2024 - 31 Mar. 2027
Grant amount(Total)：2300000, Direct funding：2300000
Grant number：24KF0153 - Exploring fundamental variables of gravity through early universe observations
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Early-Career Scientists, 01 Apr. 2020 - 31 Mar. 2024
Kyoto University
Grant amount(Total)：4030000, Direct funding：3100000, Indirect funding：930000
Grant number：20K14468 - Extended theories of gravity from fundamental physics and their observational tests
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for JSPS Fellows, 25 Apr. 2019 - 31 Mar. 2022
Kyoto University
Grant amount(Total)：4810000, Direct funding：3700000, Indirect funding：1110000
Grant number：19J00895 - Ｂｉｇｒａｖｉｔｙ理論の理論的研究及び観測的検証性
Apr. 2015 - Mar. 2018
Grant amount(Total)：3730000, Direct funding：3400000, Indirect funding：330000
Grant number：15J05540
- Theoretical Developments in Gravitational Wave Physics
Planning etc
15 Jun. 2026 - 19 Jun. 2026
Academic society etc, This workshop brings together leading experts in gravitational-wave theory and phenomenology to discuss the latest developments in the field. Topics range from established approaches—such as black-hole perturbation theory, self-force expansions, and the effective one-body formalism—to emerging directions inspired by quantum field theory and scattering amplitude methods. The program also addresses the observational and measurement aspects of gravitational-wave science, with an emphasis on future research directions and connections to related areas of fundamental physics., International academic contribution - JGRG34
Planning etc
19 Jan. 2026 - 23 Jan. 2026
Academic society etc, JGRG (General Relativity and Gravitation in Japan) has organized the annual JGRG Workshop since 1991. The workshop aims to provide an open opportunity for sharing cutting-edge results in general relativity, gravitation, and cosmology, and for discussing future directions of research.
In recent years, gravitational physics and related fields have seen remarkable progress on both observational and theoretical fronts. Gravitational-wave observations by LIGO/Virgo/KAGRA (LVK) are achieving increasing precision during the ongoing fourth observing run, while pulsar timing arrays are opening new avenues for low-frequency gravitational-wave searches. In cosmology, advances in precision observations have highlighted challenges to the standard model, such as the Hubble tension. Active research also continues in black hole physics, quantum gravity, and particle-physics–motivated cosmology, strengthening the connection between theory and observations.
Against this backdrop, the JGRG34 Workshop brought together nearly 300 participants and featured around 200 presentations. Over five days, comprehensive discussions were held on gravitational waves, black hole physics, cosmology, and quantum gravity, centered around invited talks by about ten leading researchers from Japan and abroad. Strong contributions from early-career researchers were a notable feature, with presentation awards given to six outstanding talks. The workshop fostered cross-disciplinary interactions and provided an important foundation for future collaborations and further advances in gravitational physics., International academic contribution - Progress of Theoretical Bootstrap
Planning etc
27 Oct. 2025 - 28 Nov. 2025
Academic society etc, This is a long-term workshop entitled "Progress of Theoretical Bootstrap" at Yukawa Institute for Theoretical Physics (YITP), Kyoto University, for five weeks, from Oct.27 (Mon) to Nov.28(Fri), 2025.
The long-term workshop aims to gather theoretical physicists working on bootstrap broadly defined, exchanging ideas and encouraging fruitful discussions in the relaxing atmosphere of Kyoto. The first week of the workshop is devoted to the Extreme Universe International Conference.
It is a "stay-and-discuss" style workshop, where each participant is encouraged to stay long and is assigned to a desk in an office at YITP. We arrange core discussion weeks on the 1st, 3rd, and 4th weeks, where we have several seminar sessions led by core participants. In the 2nd and 5th weeks, we arrange one or two seminar sessions including the poster sessions and contribution talks. For the remaining times other than these sessions, participants are free to work on their own research, discuss physics with other participants, have fun bootstrapping, and start new collaborations during the workshop., International academic contribution - Gravity 2025: New Horizon of Black Hole Physics
Planning etc
27 Jan. 2025 - 31 Jan. 2025
Academic society etc, Fundamental aspects of black holes have been actively studied so far to unravel the mystery of black holes and to achieve new physics like the quantum theory of gravity. Black holes are the simplest astrophysical objects in the Universe as each black hole can be characterized by a few parameters only in general relativity. For this reason, they are regarded as the best sites to probe new physics.
Given the recent developments in observational and theoretical progress in black hole physics, it is important for theoretical physicists to discuss how we can unravel the mysteries of black holes, probe new physics, and test existing theories from both fundamental and observational points of view.
This workshop aims to bring together experts working on astrophysical and fundamental aspects of black holes to share ideas and expertise and to offer introductory talks to learn relevant state-of-the-art knowledge., International academic contribution - COSMO'24
Planning etc
21 Oct. 2024 - 25 Oct. 2024
Academic society etc, COSMO is an annual international conference on particle physics and cosmology.
COSMO2024 was the 27th edition and covered the following main topics: Dark Matter,
Neutrinos and Astroparticle Physics; Gravitational Waves and Black Holes; Inflation
and the primordial universe; Large Scale Structure; Modified Gravity and Dark Energy;
Numerical Cosmology/AI; Radio Astronomy, CMB and 21cm; Statistical Methods and
Tensions in Cosmology.
The conference gathered leading researchers on these topics from all over the world
to report their latest research results and engage in active discussions for future research., International academic contribution - Gravity and Cosmology 2024
Planning etc
29 Jan. 2024 - 01 Mar. 2024
Academic society etc, In 2007, Yukawa Institute for Theoretical Physics (YITP) started new project "Yukawa International Program of Quark-Hadron Sciences (YIPQS)" funded by Japan Ministry of Education, Culture, Sports, Science and Technology. In this project we select research topics for each long-term workshop and invite leading experts to stimulate discussion and to foster collaborations among workshop participants.
This time, we hold "Gravity and Cosmology 2024", as a successor of the four long-term workshops held under the same title in the past (2007, 2010, 2012, and 2018). (The one in 2022 except YKIS2022a was canceled due to the influence of COVID-19.) The aim of the workshop is to have comprehensive but intensive discussion on the rapidly expanding frontiers of physics of gravity and cosmology., International academic contribution - Gravity 2023: Dawn of field theoretic approach
Planning etc
18 Jul. 2023 - 20 Jul. 2023
Academic society etc, We are now in a time in which novel theoretical ideas are rising to better understand various aspects of gravitational physics. One such direction is applying field theory techniques to understand gravitational systems such as effective field theory approaches, scattering amplitude techniques, and bootstrap approaches.
This workshop aims to bring together experts working on field-theoretic approaches applied to gravity to share ideas and expertise and to offer introductory talks to teach these state-of-the-art subjects to a broader audience. All talks (invited and contributed) are to be given on-site but the workshop will also be accessible for online audiences who cannot attend on-site., International academic contribution - Gravity: Current challenges in black hole physics and cosmology
Planning etc
20 Jun. 2022 - 01 Jul. 2022
Academic society etc, The goal of the workshop "Gravity: Current challenges in black hole physics and cosmology" is to bring together experts working on several aspects of the gravitational interaction to discuss the latest results, exchange ideas, and shed light on the future perspective in the field. It will include recent progress on modified gravity theories, black hole physics, and early and late time cosmology. In particular, the following topics will be covered:
Modified gravity; Scattering amplitudes and bootstrap; Black holes; Inflation and primordial black holes; Gravitational waves; Tensions in cosmology.
The workshop will be held in hybrid style (comibination of on-site and online participants) on June 20-July 1, 2022 in Yukawa Institute for Theoretical Physics (YITP), Kyoto University., International academic contribution - Gravity - The Next Generation-
Planning etc
14 Feb. 2022 - 18 Feb. 2022
Academic society etc, We hold the Yukawa International Seminar for the fiscal year 2021 (YKIS2022a) "Gravity - The Next Generation-" either online or in a hybrid style (combination of online and on-site), depending on the situation. The aim of the symposium is to have intensive discussions on the rapidly expanding frontiers of physics of gravity., International academic contribution