Research

Background

The Standard Model of particle physics was cast into its present form with Weinberg's 1967 paper and completed with the discovery of the Higgs boson in 2012. Written in the language of quantum field theory — which unifies special relativity and quantum mechanics — the Standard Model provides a theoretically inseparable description of the electromagnetic, weak, and strong interactions.

The remaining challenge is how to construct a consistent quantum theory of gravity, one of the greatest mysteries in physics for over a century. Superstring theory is expected to contain quantum gravity as a certain limit, but even after the first and second superstring revolutions the path to an ultimate theory of quantum gravity remains long.

Main research topics

Standard Model criticality & Higgs inflation

The fact that the Higgs self-coupling is nearly zero near the Planck scale — the so-called "criticality" of the Standard Model — is tied to inflation in the early universe, dark matter, and the origin of matter–antimatter asymmetry.

Quantum gravity

Mechanisms by which gravity emerges dynamically from a hidden local Lorentz symmetry, and related directions.

Wave-packet formulation of quantum field theory

Three-dimensional Gaussian wave-packet formalism refining the particle picture, decoherence in neutrino oscillations, and related topics.

Foundations of quantum mechanics

A field addressing foundational problems in quantum mechanics. In particular, we study uncertainty relations, quantum measurement, and time in quantum mechanics, among other topics.

Machine learning

Applications of deep learning and generative models to physics, and machine-learning research informed by physics-based perspectives.

Astrophysics

When stars die, the material they release travels through diverse pathways to become the building blocks of future planetary systems and life. We trace the formation and evolution of cosmic dust through molecular-scale calculations, exploring the interface with planetary science.

Lattice quantum field theory

Numerical approaches to non-perturbative quantum field theory, such as lattice QCD.

Publications

• 2026 A. Tomiya. Continuous Hasenbusch transport towards gauge diffusion with fermions. arXiv:2609.15959.
• 2026 K. Oda et al.. Emergent Einstein-Cartan gravity from a spinor loop. arXiv:2609.14627.
• 2026 B.J. Choi, H. Ohno, A. Tomiya. Bias-Corrected Machine-Learning Estimation of Chiral Condensate Cumulants: A Retrospective Lattice QCD Case Study. arXiv:2608.30416.
• 2026 A. Tomiya. Lattice Configuration Generation with a Self-Learning Diffusion Model. arXiv:2607.12587.
• 2026 K. Nishiwaki, K. Oda, J. Wada. Real and Virtual Propagation in Neutrino Oscillations. arXiv:2606.19548.
• 2026 A. Tomiya et al.. Numerical Hints for Dyon Condensation at $θ=2π$ via Wilson-'t Hooft Loops in $SU(2)$ Yang-Mills Theory, JHEP 10 (2026) 068. doi:10.1007/JHEP10(2026)068. arXiv:2606.13428.
• 2026 Y. Guan, M. Kawaguchi, S. Matsuzaki, A. Tomiya. Thermodynamics in symmetry-improved Cornwall-Jackiw-Tomboulis formalism: application to the low-energy effective theory of QCD, Phys. Rev. D 114 (2026) 054015. doi:10.1103/gqzf-qvl6. arXiv:2605.29701.
• 2026 A. Tomiya et al.. Parameter Optimization of Domain-Wall Fermion using Machine Learning, PoS LATTICE2025 (2026) 035. doi:10.22323/1.518.0035. arXiv:2603.16329.
• 2026 H. Hsiao, B.J. Choi, H. Ohno, A. Tomiya. A Machine Learning Approach for Lattice Gauge Fixing, PoS LATTICE2025 (2026) 041. doi:10.22323/1.518.0041. arXiv:2602.23731.
• 2026 A. Tomiya et al.. Machine Learning-Based Estimation of Cumulants of Chiral Condensate via Multi-Ensemble Reweighting, PoS LATTICE2025 (2026) 054. doi:10.22323/1.518.0054. arXiv:2602.21617.
• 2026 A. Tomiya et al.. Lattice Gauge Theory via LLVM-Level Automatic Differentiation. arXiv:2602.20516.
• 2026 A. Tomiya et al.. Sparse modeling study of extracting charmonium spectral functions from lattice QCD at finite temperature, Phys. Rev. D 113 (2026) 034507. doi:10.1103/cdjf-65yf. arXiv:2509.10386.
• 2026 A. Tomiya et al.. Columbia plot based on the symmetry-improved Cornwall-Jackiw-Tomboulis formalism, Phys. Rev. D 113 (2026) 014013. doi:10.1103/71r7-8b3p. arXiv:2508.02257.
• 2026 A. Tomiya et al.. Axionlike particle-assisted supercooling chiral phase transition in QCD, JHEP 03 (2026) 062. doi:10.1007/JHEP03(2026)062. arXiv:2507.18016.
• 2026 K. Oda et al.. Seeing through the light cone: Visualizing electromagnetic fields in special relativity, Eur. J. Phys. 47 (2026) 045205. doi:10.1088/1361-6404/ae8ee4. arXiv:2505.20596.
• 2025 K. Ishikawa, O. Jinnouchi, K. Nishiwaki, K. Oda. Wave-Packet Effects: A Solution for Isospin Anomalies in Vector-Meson Decay, PoS CORFU2024 (2025) 128. doi:10.22323/1.490.0128.
• 2025 K. Kaneta, K. Oda, M. Yoshimura. Observational tests for a class of scalar-tensor gravity. arXiv:2505.08286.
• 2025 K. Kaneta, K. Oda, M. Yoshimura. A common origin of two accelerating universes: inflation and dark energy. arXiv:2503.02409.
• 2025 K. Oda et al.. Implementing Errors on Errors: Bayesian vs Frequentist, Eur. Phys. J. C 85 (2025) 1022. doi:10.1140/epjc/s10052-025-14638-4. arXiv:2505.06521.
• 2025 A. Tomiya et al.. First-order CP phase transition in two-flavor QCD at θ = π under electromagnetic scale anomaly, Phys. Rev. D 111 (2025) 74028. doi:10.1103/PhysRevD.111.074028. arXiv:2502.03879.
• 2025 A. Tomiya et al.. CASK: A Gauge Covariant Transformer for Lattice Gauge Theory, PoS LATTICE2024 (2025) 030. doi:10.22323/1.466.0030. arXiv:2501.16955.
• 2025 K. Oda et al.. Spacetime and Planck mass generation from scale-invariant degenerate gravity, Phys. Rev. D 111 (2025) 046002. doi:10.1103/PhysRevD.111.046002. arXiv:2411.17238.
• 2025 A. Tomiya. Machine Learning for Lattice QCD, J. Phys. Soc. Jpn. 94 (2025) 031006. doi:10.7566/JPSJ.94.031006.
• 2025 A. Tomiya et al.. Machine Learning Estimation on the Trace of Inverse Dirac Operator using Gradient Boosting Decision Tree, PoS LATTICE2024 (2025) 033. doi:10.22323/1.466.0033. arXiv:2411.18170.
• 2025 A. Tomiya et al.. Lattice gradient flows (de-)stabilizing topological sectors, JHEP 04 (2025) 123. doi:10.1007/JHEP04(2025)123. arXiv:2411.14812.
• 2025 A. Tomiya et al.. Functional renormalization group study of a four-fermion model with CP violation, Phys. Rev. D 111 (2025) 074015. doi:10.1103/PhysRevD.111.074015. arXiv:2411.07027.
• 2025 J. Takahashi, H. Ohno, A. Tomiya. Sparse modeling study to extract spectral functions from lattice QCD data, PoS LATTICE2024 (2025) 032. doi:10.22323/1.466.0032. arXiv:2410.23567.
• 2025 K. Oda et al.. Higgs Alignment from Multicritical-Point Principle in Two Higgs Doublet Models, Eur. Phys. J. C 85 (2025) 77. doi:10.1140/epjc/s10052-025-13824-8. arXiv:2404.06096.
• 2025 K. Oda, N. Ogawa. Gaussian Formalism: Joint Measurement for Heisenberg's Uncertainty Relation for Errors, PTEP 2025 (2025) 063A02. doi:10.1093/ptep/ptaf040. arXiv:2403.19440.
• 2024 A. Tomiya et al.. JuliaQCD: Portable lattice QCD package in Julia language. arXiv:2409.03030.
• 2024 K. Oda et al.. Parametrically amplified super-radiance towards hot big bang universe, Phys. Lett. B 859 (2024) 139133. doi:10.1016/j.physletb.2024.139133. arXiv:2408.08605.
• 2024 D. Nakayama, K. Oda, K. Yasuda. Covariant Electromagnetism in Past-Light-Cone Formalism. arXiv:2408.05481.
• 2024 K. Ishikawa, O. Jinnouchi, K. Nishiwaki, K. Oda. Beyond the Plane-Wave Transitions by Wave Packets: Anomalous Kinetic Effect in Quarkonium Decays, Springer Proc. Phys. 304 (2024) 1189. doi:10.1007/978-981-97-0289-3_333.
• 2024 K. Oda et al.. Pseudo-Nambu-Goldstone Boson Production from Inflaton Coupling during Reheating, JCAP 11 (2024) 58. doi:10.1088/1475-7516/2024/11/058. arXiv:2406.09045.
• 2024 K. Oda et al.. Accelerating universe at early and late times in extended Jordan-Brans-Dicke gravity, Phys. Rev. D 110 (2024) 43518. doi:10.1103/PhysRevD.110.043518. arXiv:2405.13402.
• 2024 K. Oda et al.. Irreversible vierbein postulate: Emergence of spacetime from quantum phase transition, Phys. Rev. D 109 (2024) 106018. doi:10.1103/PhysRevD.109.106018. arXiv:2309.16230.
• 2024 K. Oda et al.. Quantum phase transition and absence of quadratic divergence in generalized quantum field theories, Phys. Rev. D 109 (2024) 85009. doi:10.1103/PhysRevD.109.085009. arXiv:2307.11420.
• 2024 K. Oda et al.. Lorentz-covariant spinor wave packet, Phys. Rev. D 110 (2024) 076001. doi:10.1103/PhysRevD.110.076001. arXiv:2307.05932.
• 2023 K. Oda et al.. Wave-Packet Effects: A Solution for Isospin Anomalies in Vector-Meson Decay, Eur. Phys. J. C 83 (2023) 978. doi:10.1140/epjc/s10052-023-12077-7. arXiv:2308.09933.
• 2023 M. Haruhi, K. Oda. Decoherence in Neutrino Oscillation between 3D Gaussian Wave Packets, Phys. Lett. B 846 (2023) 138218. doi:10.1016/j.physletb.2023.138218. arXiv:2307.12230.
• 2023 K. Oda et al.. Gravitational and dark wave emission at binary merger. arXiv:2306.07592.
• 2023 K. Kaneta, H. Lee, J. Lee, J. Yi. Misalignment mechanism for a mass-varying vector boson, JCAP 09 (2023) 017. doi:10.1088/1475-7516/2023/09/017. arXiv:2306.01291.
• 2023 K. Oda et al.. Non-thermal Higgs Spectrum in Reheating Epoch: Primordial Condensate vs. Stochastic Fluctuation, JCAP 10 (2023) 48. doi:10.1088/1475-7516/2023/10/048. arXiv:2304.12578.
• 2023 K. Oda et al.. Constraints on extended Jordan-Brans-Dicke gravity, JCAP 10 (2023) 040. doi:10.1088/1475-7516/2023/10/040. arXiv:2304.08656.
• 2023 K. Oda et al.. Gradient-flowed order parameter for spontaneous gauge symmetry breaking, Eur. Phys. J. C 83 (2023) 462. doi:10.1140/epjc/s10052-023-11553-4. arXiv:2303.10841.
• 2023 K. Oda et al.. Ultraviolet Sensitivity in Higgs-Starobinsky Inflation, JCAP 8 (2023) 045. doi:10.1088/1475-7516/2023/08/045. arXiv:2303.09866.
• 2023 K. Kaneta et al.. Quantifying Limits on CP Violating Phases from EDMs in Supersymmetry, JHEP 03 (2023) 250. doi:10.1007/JHEP03(2023)250. arXiv:2303.02822.
• 2023 P. Anastasopoulos, K. Kaneta, E. Kiritsis, Y. Mambrini. Anomalous and axial Z' contributions to g-2, JHEP 02 (2023) 051. doi:10.1007/JHEP02(2023)051. arXiv:2209.12947.
• 2023 K. Kaneta, H. Lee, J. Lee, J. Yi. Gauged Quintessence, JCAP 02 (2023) 005. doi:10.1088/1475-7516/2023/02/005. arXiv:2208.09229.
• 2023 K. Ishikawa, K. Nishiwaki, K. Oda. New effect in wave-packet scattering of quantum fields, Phys. Rev. D 108 (2023) 96013. doi:10.1103/PhysRevD.108.096013. arXiv:2102.12032.
• 2022 Y. Adachi, C.S. Lim, N. Maru. Analytic construction of sphaleron-like solution invoking higher dimensional gauge theory. arXiv:2211.12696.
• 2022 K. Oda et al.. Boltzmann or Bogoliubov? Approaches Compared in Gravitational Particle Production, JCAP 9 (2022) 18. doi:10.1088/1475-7516/2022/09/018. arXiv:2206.10929.
• 2022 Y. Adachi, C.S. Lim, N. Maru. On the vacuum structure of gauge-Higgs unification models, PTEP 2022 (2022) 093B04. doi:10.1093/ptep/ptac107. arXiv:2205.00161.
• 2022 K. Oda et al.. Double inflation via non-minimally coupled spectator, JCAP 06 (2022) 016. doi:10.1088/1475-7516/2022/06/016. arXiv:2202.04869.
• 2022 K. Oda et al.. Gravitational waves in models with multicritical-point principle, Eur. Phys. J. C 82 (2022) 481. doi:10.1140/epjc/s10052-022-10440-8. arXiv:2202.04221.
• 2022 K. Kaneta et al.. Measuring Lepton Flavor Violation at LHC, Phys. Rev. D 106 (2022) 075014. doi:10.1103/PhysRevD.106.075014. arXiv:2112.00930.
• 2022 K. Kaneta et al.. Freeze-in from Preheating, JCAP 03 (2022) 016. doi:10.1088/1475-7516/2022/03/016. arXiv:2109.13280.
• 2022 Y. Adachi, C.S. Lim, N. Maru. The strong CP problem and higher dimensional gauge theories, PTEP 2022 (2022) 053B06. doi:10.1093/ptep/ptac070. arXiv:2108.07367.
• 2022 S.M. Lee, T. Modak, K. Oda, T. Takahashi. The R2-Higgs inflation with two Higgs doublets, Eur. Phys. J. C 82 (2022) 18. doi:10.1140/epjc/s10052-021-09978-w. arXiv:2108.02383.
• 2021 K. Oda et al.. A complete set of Lorentz-invariant wave packets and modified uncertainty relation, Eur. Phys. J. C 81 (2021) 751. doi:10.1140/epjc/s10052-021-09482-1. arXiv:2104.01798.

KAKENHI grants

Kinya Oda / Akio Tomiya