Takayuki Hirayama

ORCID: 0000-0002-4118-2408
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About
Contact & Profiles
Research Areas
  • Black Holes and Theoretical Physics
  • Cosmology and Gravitation Theories
  • Earthquake and Tsunami Effects
  • Coastal and Marine Dynamics
  • Particle physics theoretical and experimental studies
  • Noncommutative and Quantum Gravity Theories
  • Ocean Waves and Remote Sensing
  • Quantum Electrodynamics and Casimir Effect
  • Earthquake and Disaster Impact Studies
  • Quantum Chromodynamics and Particle Interactions
  • Wave and Wind Energy Systems
  • Quantum Mechanics and Applications
  • Supramolecular Chemistry and Complexes
  • Microbial Metabolic Engineering and Bioproduction
  • Pulsars and Gravitational Waves Research
  • Astrophysical Phenomena and Observations
  • Ship Hydrodynamics and Maneuverability
  • Molecular Sensors and Ion Detection
  • Geotechnical Engineering and Underground Structures
  • Quantum Information and Cryptography
  • Synthesis of heterocyclic compounds
  • Relativity and Gravitational Theory
  • Fluid Dynamics Simulations and Interactions
  • Enzyme Catalysis and Immobilization
  • Statistical Distribution Estimation and Applications

Chubu University
2019-2024

Kobe University
2024

Toyo Suisan (Japan)
2019

Sansho (Japan)
2009-2019

Hosei University
2017-2019

Obayashi (Japan)
2016

Tokyo University of Science
1997-2016

Keio University
2015

Kyoto Sangyo University
2000-2011

National Taiwan Normal University
2008-2010

10.1088/1126-6708/2008/07/089 article EN Journal of High Energy Physics 2008-07-21

Recently, a botnet based DDoS (Distributed Denial of Service) attack, called target link flooding has been reported that cuts off specific links over the Internet and disconnects region from other regions. Detecting or mitigating attack is more difficult than legacy techniques, since attacking flows do not reach region. Although many mitigation schemes are proposed, they detect after it occurs. In this paper, we propose fast detection scheme by leveraging fact traceroute packets increased...

10.1109/wifs.2015.7368594 article EN 2015-11-01

In the five-dimensional Einstein gravity with negative cosmological constant in presence/absence of a {\it non-fine-tuned} 3-brane, we have investigated classical stability black string solutions which are foliations four-dimensional $AdS/dS$-Schwarzschild holes. Such strings generically unstable as well-known Gregory-Laflamme instability. For $AdS$ strings, however, it turns out that they become stable if longitudinal size horizon is larger than order $AdS_4$ radius. Even case very...

10.1103/physrevd.64.064010 article EN Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D. Particles and fields 2001-08-24

10.1016/j.nuclphysb.2010.10.018 article EN Nuclear Physics B 2010-10-23

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSyntheses of macrocyclic enzyme models. 8. Conformational mobility and molecular recognition by the internal cage kyuphaneYukito Murakami, Junichi Kikuchi, Teruhisa Ohno, Takayuki Hirayama, Yoshio Hisaeda, Hiroshi Nishimura, James P. Snyder, Kosta SteliouCite this: J. Am. Chem. Soc. 1991, 113, 22, 8229–8242Publication Date (Print):October 1, 1991Publication History Published online1 May 2002Published inissue 1 October...

10.1021/ja00022a006 article EN Journal of the American Chemical Society 1991-10-01

10.1088/1126-6708/2007/10/002 article EN Journal of High Energy Physics 2007-10-01

We use a holographic model of quantum chromodynamics to extract the equation state (EoS) for cold nuclear matter moderate baryon density. This is based on Sakai-Sugimoto in deconfined Witten's geometry with additional point-like D4-brane instanton configuration as baryons. Our EoS takes following doubly-polytropic form: $ \epsilon=2.629 {\cal A}^{-0.192} p^{1.192}+0.131 A}^{0.544} p^{0.456}$ $\cal A$ tunable parameter order $10^{-1}$, where $\epsilon$ and $p$ are energy density pressure,...

10.1016/j.physletb.2019.135176 article EN cc-by Physics Letters B 2019-12-27

10.1088/1126-6708/2006/06/013 article EN Journal of High Energy Physics 2006-06-09

10.1088/1126-6708/2007/06/020 article EN Journal of High Energy Physics 2007-06-06

We compute a shift of baryon mass spectra due to quark masses in perturbation, the Sakai-Sugimoto model holographic QCD. find for ground state nucleons be $\ensuremath{\delta}M=4.1{m}_{\ensuremath{\pi}}^{2}\text{ }\text{ }{\mathrm{GeV}}^{\ensuremath{-}1}$, which is consistent with current lattice QCD result. predict same value $N(1535)$, while larger $7.7{m}_{\ensuremath{\pi}}^{2}\text{ }{\mathrm{GeV}}^{\ensuremath{-}1}$ Roper $N(1440)$. also present some evidences that shifts vector meson...

10.1103/physrevd.81.045016 article EN Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D, Particles, fields, gravitation, and cosmology 2010-02-19

We have investigated the classical stability of magnetically charged black p-brane solutions for string theories that include case studied by Gregory and Laflamme. It turns out behaves very differently depending on coupling parameter between dilaton gauge fields. In Laflamme, it is known brane instability decreases monotonically as charge branes increases finally disappears at extremal point. For more general cases we found that, when small, become stable even before reaching On other hand,...

10.1103/physrevd.67.024007 article EN Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D. Particles and fields 2003-01-15

A bstract We propose a procedure of computing the n-point function in perturbation theory quantum field as average over complex Gaussian noises classical theory. The are sources for creation and annihilation particles energy resultant configuration is same zero point corresponding

10.1007/jhep01(2024)097 article EN cc-by Journal of High Energy Physics 2024-01-17

A vibration isolation system called the Type-Bp used for power recycling mirrors has been developed KAGRA, interferometric gravitational-wave observatory in Japan. suspension of passively isolates an optic from seismic using three main pendulum stages equipped with two vertical systems. compact reaction mass around each allows achieving sufficient damping performance a simple feedback as well ratio. Three systems were installed and proved to satisfy requirements on performance, also...

10.1088/1361-6382/ab0fcb article EN Classical and Quantum Gravity 2019-03-14

Abstract A cubic macrocycle, each face being constructed with the 2,11,20,29-tetraaza[3.3.3.3]paracyclophane ring, was prepared as a novel host molecule which provides relatively rigid and hydrophobic three-dimensional cavity, its guest-binding behavior examined in acidic aqueous media.

10.1246/cl.1987.161 article EN Chemistry Letters 1987-01-01

We study non-conformal negative modes of black holes in the five-dimensional Einstein–Gauss–Bonnet gravity theory with a zero or cosmological constant (which become Schwarzschild Einstein limit), context semiclassical quantum formulated by path integral. find unique mode when hole has heat capacity which is same theory. On other hand, we still inside parameter region where small positive capacity. The number one/two for case zero/negative constant, respectively. In rest positive, no modes....

10.1088/0264-9381/25/24/245006 article EN Classical and Quantum Gravity 2008-11-27

Abstract A cubic cyclophane surrounded by six faces, each being constructed with the [3.3.3.3]azaparacyclophane ring, behaved as a polycationic host in acidic aqueous media and exhibited size-sensitive regioselective molecular discrimination that originates from rigid geometry of its hydrophobic cavity.

10.1246/cl.1989.881 article EN Chemistry Letters 1989-05-01

The search for regular black hole solutions in classical gravity leads us to consider a core of Euclidean signature the interior hole. Solutions Lorentzian and general relativity match such way that energy densities pressures an isotropic perfect fluid form are everywhere finite continuous. Although weak condition cannot be satisfied these relativity, it can when higher derivative terms added. A numerical study shows how transition becomes smoother theories with more derivatives. As...

10.1103/physrevd.68.044003 article EN Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D. Particles and fields 2003-08-05

10.1088/1126-6708/2000/11/014 article EN Journal of High Energy Physics 2000-11-08

We compute the particle creation of a harmonic oscillator using classical stochastic method. This method reproduces all vacuum expectation values in quantum theory. prepare state at initial time and evolve it over Langevin equations motion. By averaging ensemble, we energy final determine amount particles created. verify that agrees with predictions from

10.48550/arxiv.2406.04125 preprint EN arXiv (Cornell University) 2024-06-06
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