Yamamoto, Naoki

写真a

Affiliation

Faculty of Science and Technology, Department of Physics (Yagami)

Position

Professor

Related Websites
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Career 【 Display / hide 】

  • 2007.04
    -
    2010.03

    東京大学, 大学院理学系研究科, 日本学術振興会 特別研究員 (DC1)

  • 2010.04
    -
    2012.03

    University of Washington, Institute for Nuclear Theory, JSPS Postdoctoral Fellow for Research Abroad / Research Associate

  • 2012.04
    -
    2013.08

    京都大学, 基礎物理学研究所, 日本学術振興会 特別研究員 (PD)

  • 2013.09
    -
    2014.03

    University of Maryland, Maryland Center for Fundamental Physics, Research Associate

  • 2014.04
    -
    2017.03

    慶應義塾大学, 理工学部物理学科, 専任講師

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Academic Background 【 Display / hide 】

  • 2001.04
    -
    2005.03

    The University of Tokyo, 理学部, Department of Physics

    University, Graduated

  • 2005.04
    -
    2007.03

    The University of Tokyo, Faculty of Science, Department of Physics

    Graduate School, Completed, Master's course

  • 2007.04
    -
    2010.03

    The University of Tokyo, Faculty of Science, Department of Physics

    Graduate School, Completed, Doctoral course

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Academic Degrees 【 Display / hide 】

  • 博士（理学）, The University of Tokyo, Coursework, 2010.03

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Research Areas 【 Display / hide 】

  • Natural Science / Theoretical studies related to particle-, nuclear-, cosmic ray and astro-physics

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Books 【 Display / hide 】

  • Crossover Between Quark Nuclear Matter and Condensed-Matter Physics

    Tomáš Brauner, Naoki Yamamoto, Springer, 2023.01

    　View Summary

    We review quantum many-body phenomena in nuclear and quark matter which share similarities or universalities with condensed-matter physics. The focus is on the quantum phases of quark nuclear matter and topological transport phenomena due to the Berry phase of quark matter. The former includes nuclear superfluidity/superconductivity via the Bardeen–Cooper–Schrieffer (BCS) mechanism, Bose–Einstein condensation (BEC) of mesons, color superconductivity of quarks, BCS–BEC crossover phenomena and quark–hadron continuity, chiral soliton lattice of mesons, and the application of the notions of topological order and higher-form symmetry. The latter includes the so-called chiral magnetic effect and related phenomena. Their potential phenomenological implications as well as the close connections with a number of condensed-matter systems are also discussed.

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Papers 【 Display / hide 】

  • Quantum Hall liquids in high-density QCD

    Kentaro Nishimura, Naoki Yamamoto, Ryo Yokokura

    Physical Review D 111 ( 5 ) 054010(1-7) 2025.03

    Research paper (scientific journal), Joint Work, Accepted,  ISSN  24700010

    　View Summary

    There exist metastable domain walls of the flavor-singlet meson η for the U(1) axial symmetry in two-flavor color superconductivity (2SC) in quantum chromodynamics (QCD) at large baryon density. We show that, due to the coupling of η to confined SU(2) gluons in the 2SC phase, the effective theory on the domain wall is described by the SU(2)-1 Chern-Simons theory, which is dual to the U(1)2 Chern-Simons theory. This theory has a spin-1 droplet excitation that does not carry a baryon number, which we identify as a vector meson. We also discuss the effective theories and baryonic droplet excitations on the domain walls of the flavor-singlet mesons in the superfluid phases of QCD at large isospin density and two-color QCD at large baryon density.

  • Chiral kinetic theory with self-energy corrections and neutrino spin Hall effect

    Naoki Yamamoto, Di-Lun Yang

    Physical Review D 109 ( 5 ) 056010(1-14) 2024.03

    Research paper (scientific journal), Joint Work, Accepted,  ISSN  24700010

    　View Summary

    We systematically derive the chiral kinetic theory for chiral fermions with collisions, including the self-energy corrections, from quantum field theories. We find that the Wigner functions and chiral kinetic equations receive both the classical and quantum corrections from the self-energies and their spacetime gradients. We also apply this formalism to study nonequilibrium neutrino transport due to the interaction with thermalized electrons and nucleons, as realized in core-collapse supernovae. We derive neutrino currents along magnetic fields and neutrino spin Hall effect induced by the density gradient at first order in the Fermi constant GF for anisotropic neutrino distributions.

  • Convergence of Ginzburg–Landau Expansions: Superconductivity in the Bardeen–Cooper–Schrieffer Theory and Chiral Symmetry Breaking in the Nambu–Jona-Lasinio Model

    William Gyory, Naoki Yamamoto

    Progress of Theoretical and Experimental Physics (The Physical Society of Japan)  2024 ( 4 ) 043D01(1-19) 2024.03

    Research paper (scientific journal), Joint Work, Accepted

    　View Summary

    We study the convergence of the Ginzburg–Landau (GL) expansion in the context of the Bardeen–Cooper–Schrieffer (BCS) theory for superconductivity and the Nambu–Jona-Lasinio (NJL) model for chiral symmetry breaking at finite temperature T and chemical potential μ. We present derivations of the all-order formulas for the coefficients of the GL expansions in both systems under the mean-field approximation. We show that the convergence radii for the BCS gap ∆ and dynamical quark mass M are given by ∆conv = πT and Mconv = √μ2 + (πT)2, respectively. We also discuss the implications of these results and the quantitative reliability of the GL expansion near the first-order chiral phase transition.

  • Dipole symmetries from the topology of the phase space and the constraints on the low-energy spectrum

    Tomáš Brauner, Naoki Yamamoto, Ryo Yokokura

    SciPost Physics 16 ( 2 ) 051:1 - 051:32 2024.02

    Research paper (scientific journal), Joint Work, Accepted

    　View Summary

    We demonstrate the general existence of a local dipole conservation law in bosonic field theory. The scalar charge density arises from the symplectic form of the system, whereas the tensor current descends from its stress tensor. The algebra of spatial translations becomes centrally extended in presence of field configurations with a finite nonzero charge. Furthermore, when the symplectic form is closed but not exact, the system may, surprisingly, lack a well-defined momentum density. This leads to a theorem for the presence of additional light modes in the system whenever the short-distance physics is governed by a translationally invariant local field theory. We also illustrate this mechanism for axion electrodynamics as an example of a system with Nambu–Goldstone modes of higher-form symmetries.

  • Chiral asteroseismology: seismic oscillations caused by chiral transport in neutron stars and supernovae

    Sota Hanai, Naoki Yamamoto

    Journal of Cosmology and Astroparticle Physics 10 ( 018 ) 1 - 25 2023.10

    Research paper (scientific journal), Joint Work, Accepted

    　View Summary

    We study the novel asteroseismology of the chiral magnetic wave (CMW) of the quark number density in relativistic quark matter inside neutron stars and core-collapse supernovae and the chiral vortical wave (CVW) of the neutrino number density in relativistic neutrino matter at the core of supernovae. We call the oscillation modes for these chiral waves the chiral magnetic mode (CM-mode) and chiral vortical mode (CV-mode), respectively. We derive the dispersion relations of these new modes in the presence of the chirality flipping due to the finite quark mass and diffusion. We then estimate the possible frequencies of these modes and amplitudes of the resulting gravitational waves. In particular, since the CM-mode can exist only in quark matter with nearly gapless quarks (such as the two-flavor color superconductivity) for a sufficiently strong magnetic field, corresponding gravitational waves provide a new possible probe for such quark matter and the magnetic field in neutron stars.

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Papers, etc., Registered in KOARA 【 Display / hide 】

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Reviews, Commentaries, etc. 【 Display / hide 】

  • カイラリティと宇宙

    山本 直希

    数理科学（特集：カイラリティとは何か） 59 ( 3 ) 45 - 51 2021.03

    Article, review, commentary, editorial, etc. (trade magazine, newspaper, online media), Single Work

  • トポロジカル輸送現象入門

    山本 直希

    原子核研究 64   22 - 29 2020.02

    Article, review, commentary, editorial, etc. (scientific journal)

  • Chiral Transport Phenomena

    山本 直希

    原子核研究 63 ( 2 ) 72 - 73 2019.03

    Article, review, commentary, editorial, etc. (scientific journal), Single Work

  • 相対論的流体力学

    山本 直希

    数理科学（特集：相対論的思考法のすすめ） 55 ( 8 ) 36 - 42 2017.08

    Article, review, commentary, editorial, etc. (trade magazine, newspaper, online media), Single Work

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Presentations 【 Display / hide 】

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Research Projects of Competitive Funds, etc. 【 Display / hide 】

  • ニュートリノカイラル輸送理論で解き明かす中性子星磁場の起源と超新星の爆発機構

    2024.04
    -
    2027.03

    基盤研究(B), Principal investigator

  • 素粒子論に基づく超新星のカイラル輻射流体力学の構築

    2019.04
    -
    2022.03

    MEXT,JSPS, Grant-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (C), Principal investigator

  • カイラル輸送現象による超新星爆発・初期宇宙の新物理

    2016.04
    -
    2019.03

    MEXT,JSPS, Grant-in-Aid for Scientific Research, Grant-in-Aid for Young Scientists (B), Principal investigator

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Works 【 Display / hide 】

  • 他研究所セミナー招待講演（東京大学 物性研究所）

    山本直希

    東京大学物性研究所, 

    2025.04
    , 

    Other, Single

  • 他大学セミナー招待講演（大阪大学 素粒子論研究室）

    山本直希

    大阪大学 素粒子論研究室, 

    2024.11
    , 

    Other, Single

  • 他大学セミナー講演（東北大学 原子核理論研究室）

    山本 直希

    東北大学, 

    2023.11
    , 

    Other, Single

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    弱い力のパリティの破れと超新星

  • 他大学セミナー招待講演（東京工業大学 宇宙論研究室）

    山本 直希

    東京工業大学, 

    2022.07
    , 

    Other

    　View Details

    Gravitational Spin Hall Effect

  • 他研究所セミナー招待講演（高エネルギー加速器研究機構）

    山本 直希

    オンライン, 

    2020.07
    , 

    Other

    　View Details

    Magnetic monopoles and fermion number violation in chiral matter

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Awards 【 Display / hide 】

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Courses Taught 【 Display / hide 】

  • QUARK-HADRON PHYSICS

    2025

  • QUANTUM MECHANICS 3

    2025

  • PHYSICS B

    2025

  • PHYSICS A

    2025

  • NUCLEAR PHYSICS

    2025

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Social Activities 【 Display / hide 】

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Memberships in Academic Societies 【 Display / hide 】

  • 日本物理学会, 

    2006.09
    -
    Present
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