Results for "Ryosuke Akashi"

total 258took 0.22s
Neural-network Kohn-Sham exchange-correlation potential and its out-of-training transferabilityFeb 08 2018We incorporate in the Kohn-Sham self consistent equation a trained neural-network projection from the charge density distribution to the Hartree-exchange-correlation potential $n \rightarrow V_{\rm Hxc}$ for possible numerical approach to the exact Kohn-Sham ... More
Development of Density-Functional Theory for Plasmon-Assisted Superconducting State: Application to Lithium Under High PressuresMar 21 2013Jan 07 2014We extend the density-functional theory for superconductors (SCDFT) to take account of the dynamical structure of the screened Coulomb interaction. We construct an exchange-correlation kernel in the SCDFT gap equation on the basis of the random-phase ... More
Two-Dimensional Valley Electrons and Excitons in Noncentrosymmetric 3R MoS$_{2}$Feb 26 2015Jul 11 2015We find that the motion of the valley electrons -- electronic states close to the ${\rm K}$ and ${\rm K'}$ points of the Brillouin zone -- is confined into two dimension when the layers of MoS$_{2}$ follow the 3R stacking, while in the 2H polytype the ... More
Density Functional Theory for Superconductors with Particle-hole Asymmetric Electronic StructureMay 02 2013To extend the applicability of density functional theory for superconductors (SCDFT) to systems with significant particle-hole asymmetry, we construct a new exchange-correlation kernel entering the gap equation. We show that the kernel is numerically ... More
Density Functional Theory for Plasmon-Assisted SuperconductivityJan 08 2014We review the recent progress in the density functional theory for superconductors (SCDFT). Motivated by the long-studied plasmon mechanism of superconductivity, we have constructed an exchange-correlation kernel entering the SCDFT gap equation which ... More
Non-empirical Study of Superconductivity in Alkali-doped Fullerides Based on Density Functional Theory for SuperconductorsMar 21 2013We apply the density functional theory for superconductors (SCDFT) based on the local-density approximation (LDA) to alkali-doped fullerides A3C60 with the face-centered cubic structure. We evaluate the superconducting transition temperature (Tc) from ... More
Anisotropic superconducting gaps in YNi$_2$B$_2$C: A first-principles investigationOct 24 2016We calculate superconducting gaps and quasiparticle density of states of YNi$_2$B$_2$C in the framework of the density functional theory for superconductors to investigate the origin of a highly anisotropic superconducting gaps in this material. Calculated ... More
Strong bilayer coupling induced by the symmetry breaking in the monoclinic phase of BiS$_2$-based superconductorsDec 12 2015Aug 05 2016We perform first-principles band structure calculations for the tetragonal and monoclinic structures of LaO$_{0.5}$F$_{0.5}$BiS$_2$. We find that the Bi $6p_{x,y}$ bands on two BiS$_2$ layers exhibit a sizable splitting at the X = ($\pi$, 0, 0) and several ... More
Shaping Planetary Nebulae by JetsSep 06 2007We conduct 2D axisymmetrical hydrodynamical simulations to investigate the interaction of a collimated fast wind (CFW; wide jets) with a spherical AGB wind. The code includes radiative cooling. We find that the shape of the planetary nebula (PN) is sensitive ... More
High-temperature Superconductivity in Layered Nitrides β-Li$_x$MNCl (M = Ti, Zr, Hf): Insights from Density-functional Theory for SuperconductorsMar 29 2012We present an ab initio analysis with density functional theory for superconductors (SCDFT) to understand the superconducting mechanism of doped layered nitrides \beta-Li$_x$MNCl (M=Ti, Zr, and Hf). The current version of SCDFT is based on the Migdal-Eliashberg ... More
Effect of van Hove singularities on high-Tc superconductivity in H3SDec 23 2015Jan 07 2016One of interesting open questions for the high transition temperature (Tc) superconductivity in sulfur hydrides is why high pressure phases of H3S have extremely high Tc's. Recently, it has been pointed out that the presence of the van Hove singularities ... More
First-principles study of the pressure and crystal-structure dependences of the superconducting transition temperature in compressed sulfur hydridesFeb 03 2015Jul 07 2015We calculate superconducting transition temperatures ($T_{\rm c}$) in sulfur hydrides H$_{2}$S and H$_{3}$S from first principles using the density functional theory for superconductors. At pressures of $\lesssim$150 GPa, the high values of $T_{\rm c}$ ... More
An efficient method for calculating spatially extended electronic states of large systems with a divide-and-conquer approachNov 19 2016We present an efficient post-processing method for calculating the electronic structure of nanosystems based on the divide-and-conquer approach to density functional theory (DC-DFT), in which a system is divided into subsystems whose electronic structure ... More
Interference of the Bloch phase and stacking geometry in layered materialsMay 17 2016May 19 2016Every electronic one-body wavefunction of the eigenstate in the periodic system is factorized into the cell-periodic function and plane wave. We address effects of the latter factor on the hybridization between the states, which is in principle dependent ... More
Numerical Investigation of Triexciton Stabilization in Diamond with Multiple Valleys and BandsSep 08 2016The existence of polyexcitons, the $N$-body complexes of excitons for $N > 2$ in 3D bulk systems, has been controversial for more than 40 years since its first theoretical suggestion. We investigated the stability of fundamental excitonic complexes in ... More
Possible "Magnéli" phases and self-alloying in the superconducting sulfur hydrideDec 21 2015Aug 11 2016We theoretically give an infinite number of metastable crystal structures for the superconducting sulfur hydride H$_{x}$S under pressure. It has been thought that theoretically predicted structures of H$_{2}$S and H$_{3}$S exhibit low and high $T_{\rm ... More
A Model for the Formation of Large Circumbinary Disks Around Post AGB StarsJun 26 2007Sep 02 2007We propose that the large, radius of ~1000 AU, circumbinary rotating disks observed around some post-asymptotic giant branch (post-AGB) binary stars are formed from slow AGB wind material that is pushed back to the center of the nebula by wide jets. We ... More
Bipolar rings from jet-inflated bubbles around evolved binary starsMay 09 2016We show that a fast wind that expands into a bipolar nebula composed of two opposite jet-inflated bubbles can form a pair of bipolar rings around giant stars. Our model assumes three mass loss episodes: a spherical slow and dense shell, two opposite jets, ... More
Shaping Planetary Nebulae by Light JetsMay 15 2008We conduct numerical simulations of axisymmetrical jets expanding into a spherical AGB slow wind. The three-dimensional flow is simulated with an axially symmetric numerical code. We concentrate on jets that are active for a relatively short time. Our ... More
Impulsive Ejection of Gas In Bipolar Planetary NebulaeMay 27 2013Sep 11 2013We simulate the formation of bipolar planetary nebulae (PNe) through very short impulsive mass ejection events from binary systems, where the asymptotic giant branch (AGB) star ejects a mass shell that is accelerated by jets launched from a compact companion. ... More
The Role of Gravity in Winds Collision in the eta Carinae Binary SystemJun 16 2010Nov 02 2010We conduct 3D numerical simulations of the winds collision process in the massive binary system Eta Carinae, and conclude that accretion occurs during periastron passage. We include radiative cooling of the two winds, one from each star, and the gravity ... More
Profile Control of a Borosilicate-Glass Groove Formed by Deep Reactive Ion EtchingFeb 21 2008Deep reactive ion etching (DRIE) of borosilicate glass and profile control of an etched groove are reported. DRIE was carried out using an anodically bonded silicon wafer as an etching mask. We controlled the groove profile, namely improving its sidewall ... More
Affine Yangian action on the Fock spaceJun 03 2015Jul 12 2016The localized equivariant homology of the quiver variety of type $A_{N-1}^{(1)}$ can be identified with the level one Fock space by assigning a normalized torus fixed point basis to certain symmetric functions, Jack($\mathfrak{gl}_N$) symmetric functions ... More
Bergman iteration and $C^{\infty}$-convergence towards Kähler-Ricci flowJun 09 2016Jul 13 2016Bergman iteration is a numerical algorithm to find a solution of K\"ahler-Ricci flow. We study the limiting behavior of Bergman iteration and show the $C^{\infty}$-convergence towards K\"ahler-Ricci flow.
Kähler manifolds with negative holomorphic sectional curvature, Kähler-Ricci flow approachOct 06 2016Recently, Wu-Yau and Tosatti-Yang established the connection between the negativity of holomorphic sectional curvatures and the positivity of canonical bundles for compact K\"ahler manifolds. In this short note, we give anothe proof of their theorems ... More
Geometric intersection number of simple closed curves on a surface and symplectic expansions of free groupsDec 06 2016For two oriented simple closed curves on a compact orientable surface with a connected boundary we introduce a simple computation of a value in the first homology group of the surface, which detects in some cases that the geometric intersection number ... More
Integral formula and upper estimate of I and J-Bessel functions on Jordan algebrasNov 20 2012Dec 06 2013In this paper we give a new integral expression of I and J-Bessel functions on simple Euclidean Jordan algebras, integrating on a bounded symmetric domain. From this we easily get the upper estimate of Bessel functions. As an application we give an upper ... More
Numerical method toward fast and accurate calculation of dilute quantum gas using Uehling-Uhlenbeck model equationNov 23 2015Apr 28 2016The numerical method toward the fast and accurate calculation of the dilute quantum gas is studied by proposing the Uehing-Uhlenbeck (U-U) model equation. In particular, the direct simulation Monte Carlo (DSMC) method is used to solve the U-U model equation. ... More
An Ancient Solution of The Ricci Flow in Dimension 4 Converging to the Euclidean Schwarzschild MetricJun 26 2012In this paper, we prove the existence of an ancient solution to the Ricci flow whose limit at $t=-\infty$ is the Euclidean Schwarzschild metric.
Schwarz lemma for conical Kähler metrics with general cone anglesOct 06 2016The Schwarz--Pick lemma is a fundamental result in complex analysis. It is well-known that Yau generalized it to the higher dimensional manifolds by applying his maximum principle for complete Riemannian manifolds. Jeffres obtained Schwarz lemma for volume ... More
Bergman iteration and $C^{\infty}$-convergence towards Kähler-Ricci flowJun 09 2016Nov 28 2016Bergman iteration is a numerical algorithm to find a solution of K\"ahler-Ricci flow. We study the limiting behavior of Bergman iteration and show the $C^{\infty}$-convergence towards K\"ahler-Ricci flow.
On the modified Futaki invariant of complete intersections in projective spacesOct 18 2014Jun 09 2016It is known that a necessary condition for the existence of K\"ahler-Ricci solitons is the vanishing of the modified Futaki invariant introduced by Tian-Zhu. In a recent work of Berman-Nystr\"om, it was generalized for (singular) Fano varieties and the ... More
Thermal fluctuations of granular gas driven by Gaussian thermostat based on two-point kinetic theoryDec 30 2015In this paper, we investigate thermal fluctuations of the granular gas, which is driven by Gaussian thermostat, on the basis of two-point kinetic theory. In particular, we consider thermal fluctuations of the inelastic variable sphere, which was proposed ... More
From conduction to convection of thermally relativistic fluids between two parallel walls under gravitational forceDec 27 2014Aug 21 2015We discuss the thermal conduction and convection of thermally relativistic fluids between two parallel walls under the gravitational force, both theoretically and numerically. In the theoretical discussion, we assume that the Lorentz contraction is ignored ... More
Open books supporting overtwisted contact structures and Stallings twistAug 15 2006Aug 28 2006We study open books (or open book decompositions) of a closed oriented 3-manifold which support overtwisted contact structures. We focus on a simple closed curve along which one can perform Stallings twist, called ``twisting loop''. We show that the existence ... More
Asymptotic stability for Kähler-Ricci solitonsMar 19 2015Jul 30 2015We show that the coercivity of the modified Ding functional leads to the existence of a certain kind of balanced metrics and their convergence to the K\"ahler-Ricci soliton modulo automorphisms. In our results, we do not assume that the vanishing of the ... More
Measurements of time dependent CP asymmetry in $B \to VV$ decays with BELLEOct 09 2002A study of CP violation in $B\to J/\psi K^*(K_S^0\pi^0)$ decays by time dependent angular analysis is discussed. Status of time independent analyses for other $B\to VV$ decays is also reported. The data used for the analyses are taken with the Belle detector ... More
A generalization of adjoint crystals for the quantized affine algebras of type $A\sb{n}\sp{(1)}$, $C\sb{n}\sp{(1)}$ and $D\sb{n+1}\sp{(2)}$Feb 27 2008We propose to generalize Benkart-Frenkel-Kang-Lee's adjoint crystals and describe their crystal structure for type $A\sb{n}\sp{(1)}$, $C\sb{n}\sp{(1)}$ and $D\sb{n+1}\sp{(2)}$.
Nonlocal effect on the magnetic penetration depth in multigapped superconductorsJun 12 2007Jul 24 2007A brief discussion is given on the nonlocal effect in multigapped superconductivity. It is pointed out that the effective magnetic penetration depth at lower external fields may be reduced by the nonlocal effect associated with the presence of small energy ... More
Extensions between finite-dimensional simple modules over a generalized current Lie algebraAug 26 2009Aug 30 2009We calculate the first extension groups for finite-dimensional simple modules over an arbitrary generalized current Lie algebra, which includes the case of loop Lie algebras and their multivariable analogs.
Modified Kähler-Ricci flow on projective bundlesMar 05 2014Jul 30 2015In this paper, we propose a method of studying the modified Kahler-Ricci flow on projective bundles and give the explicit equation from the view point of symplectic geometry.
Norm computation and analytic continuation of vector valued holomorphic discrete series representationsJun 19 2015In this paper we compute explicitly the norm of the vector-valued holomorphic discrete series representations, when its $K$-type is "almost multiplicity-free." As an application, we discuss the properties of highest weight modules, such as unitarizability, ... More
Higher level Fock spaces and affine YangianJul 12 2016We construct actions of the affine Yangian of type A on higher level Fock spaces by extending known actions of the Yangian of finite type A due to Uglov. This is a degenerate analog of a result by Takemura-Uglov, which constructed actions of the quantum ... More
Dissipation process of binary mixture gas in thermally relativistic flowDec 30 2015In this paper, we discuss dissipation process of the binary mixture gas in the thermally relativistic flow \textcolor{red}{by focusing on the characteristics of the diffusion flux}. As an analytical object, we consider the relativistic rarefied-shock ... More
The moduli space of $S^1$-type zero loci for $\mathbb{Z}/2$-harmonic spinors in dimension 3Mar 02 2015May 06 2015Let $M$ be a compact oriented 3-dimensional smooth manifold. In this paper, we will construct a moduli space consisting of the following date $\{(\Sigma, \psi)\}$ where $\Sigma$ is a $C^1$-embedding $S^1$ curve in $M$, $\psi$ is a $\mathbb{Z}/2$-harmonic ... More
Blow-up behavior of the scalar curvature along the conical Kähler-Ricci flow with finite time singularitiesJul 11 2016We investigate the scalar curvature behavior along the normalized conical K\"ahler-Ricci flow $\omega_t$, which is the conic version of the normalized K\"ahler-Ricci flow, with finite maximal existence time $T<\infty $. We prove that the scalar curvature ... More
Accretion of Dense Clumps in the Periastron Passage of Eta CarinaeJun 13 2011Jun 24 2012We perform 3D hydrodynamical numerical simulations of the winds interaction process in the massive binary system $\eta$ Carinae, and find the secondary star to accrete mass from the dense primary wind close to periastron passage. This accretion is thought ... More
Change point detection in autoregressive models with no moment assumptionsDec 04 2016In this paper we consider the problem of detecting a change in the parameters of an autoregressive process, where the moments of the innovation process do not necessarily exist. An empirical likelihood ratio test for the existence of a change point is ... More
X-Ray Emission by A Shocked Fast Wind from the Central Stars of Planetary NebulaeAug 17 2005Feb 27 2006We calculate the X-ray emission from the shocked fast wind blown by the central stars of planetary nebulae (PNs) and compare with observations. Using spherically symmetric self similar solutions, we calculate the flow structure and X-ray temperature for ... More
Numerical simulations of wind-equatorial gas interaction in eta CarinaeSep 02 2012Dec 23 2012We perform three-dimensional gas-dynamical simulations and show that the asymmetric morphology of the blue and red-shifted components of the outflow at hundreds of astronomical units (AU) from the massive binary system eta Carinae can be accounted for ... More
X-Ray Emission from Jet-Wind Interaction in Planetary NebulaeNov 21 2007We conduct 2D numerical simulations of jets expanding into the slow wind of asymptotic giant branch stars. We show that the post-shock jets' material can explain the observed extended X-ray emission from some planetary nebulae (PNs). Such jets are thought ... More
Explaining the transient fast blue absorption lines in the massive binary system Eta CarinaeApr 15 2010Jan 29 2011We use recent observations of the He I $\lambda10830 \AA$ absorption line and 3D hydrodynamical numerical simulations of the winds collision, to strengthen the case for an orientation of the semimajor axis of the massive binary system Eta Carinae where ... More
An empirical likelihood approach for symmetric $α$-stable processesJul 24 2014Sep 18 2015Empirical likelihood approach is one of non-parametric statistical methods, which is applied to the hypothesis testing or construction of confidence regions for pivotal unknown quantities. This method has been applied to the case of independent identically ... More
A 125 GeV Higgs Boson Mass and Gravitino Dark Matter in R-invariant Direct Gauge MediationApr 16 2012Sep 20 2012We discuss the SM-like Higgs boson mass in the MSSM in an R-invariant direct gauge mediation model with the gravitino mass in the O(1) keV range. The gravitino dark matter scenario in this mass range is a good candidate for a slightly warm dark matter. ... More
LHC Reach of Low Scale Gauge Mediation with Perturbatively Stable VacuumMay 07 2010Aug 20 2010Very light gravitino scenario m_{3/2} < 16 eV is very interesting, since there is no cosmological problem. However in such a scenario, stability of the vacuum is an important issue. Recently, Yonekura and one of the authors RS have investigated the parameter ... More
Loewy series of Weyl modules and the Poincaré polynomials of quiver varietiesMar 22 2011We prove that a Weyl module for the current Lie algebra associated with a simple Lie algebra of type $ADE$ is rigid, that is, it has a unique Loewy series. Further we use this result to prove that the grading on a Weyl module defined by the degree of ... More
Composite HiggsinoNov 26 2013Mar 31 2014Several supersymmetric models in which there is a (partially) composite Higgs boson arising from (coupled to) a strong sector have been proposed. Such strong dynamics would help to cause the electroweak symmetry breaking naturally. In this paper, we focus ... More
Valence Imbalance of Manganese Ions between Surface and Bulk Enhanced by Fermi-Surface Structure in Layered ManganitesJan 06 2016Jan 07 2016To investigate valence imbalance phenomena between the surface and bulk in layered manganites, we analyze an eg-orbital degenerate double-exchange model with surfaces for two types of t2g spin structures. We reconfirm that the surface-induced Friedel ... More
1D inelastic relativistic-collisionDec 27 2014In this paper, we discuss one dimensional inelastic relativistic-collisions in the framework of the relativistic kinetic theory. In particular, we focus on the relativistic effects on time evolutions of the temperature and flow velocity under the spatially ... More
Geometrical pumping in spin coupled double quantum dotsFeb 27 2013We analytically investigate the non-equilibrium pumping for a double quantum dots system on the basis of the quantum master equation (QME), where the double quantum dots are connected to two external leads by the spin coupling. Each of leads has two tunable ... More
An obstruction to the existence of anti-canonically balanced metrics on Fano manifoldsJul 19 2016We introduce a new obstruction to the existence of anti-canonically balanced metrics by studying the asymptotic behavior of the quantized Ding functional along Bergman geodesic rays associated to special test configurations. We also discuss some relation ... More
Low Scale Direct Gauge Mediation with Perturbatively Stable VacuumDec 15 2009Mar 02 2010In a class of direct gauge mediation with a perturbatively stable SUSY breaking vacuum, gaugino masses vanish at the leading order of SUSY breaking F-term. We study the allowed parameter space of the gauge mediation models. By imposing a Tevatron bound ... More
LHC Future Prospects of the 750 GeV ResonanceMay 17 2016Aug 22 2016A quantitative discussion on the future prospects of the 750 GeV resonance at the LHC experiment is given using a simple effective field theory analysis. The relative size of two effective operators relevant to diphoton decays can be probed by ratios ... More
Dynamics of social balance under temporal interactionMar 19 2014Aug 25 2014Real social contacts are often intermittent such that a link between a pair of nodes in a social network is only temporarily used. Effects of such temporal networks on social dynamics have been investigated for several phenomenological models such as ... More
Analytical expression of geometrical pumping for a quantum dot based on quantum master equationDec 13 2013We analytically investigate a non-equilibrium quantum pumping for a single quantum dot connected to external leads on the basis of the quantum master equation (QME). We show that the Coulomb interaction associated with the spin effect in the dot induces ... More
Scaling analysis of Kondo screening cloud in a mesoscopic ring with an embedded quantum dotDec 01 2010The Kondo effect is theoretically studied in a quantum dot embedded in a mesoscopic ring. The ring is connected to two external leads, which enables the transport measurement. Using the "poor man's" scaling method, we obtain analytical expressions of ... More
Forming equatorial rings around dying starsFeb 19 2015Jul 01 2015We suggest that clumpy-dense outflowing equatorial rings around evolved giant stars, such as in supernova 1987A and the Necklace planetary nebula, are formed by bipolar jets that compress gas toward the equatorial plane. The jets are launched from an ... More
X-Ray Emission from Planetary Nebulae Calculated by 1D Spherical Numerical SimulationsOct 17 2006Nov 13 2006We calculate the X-ray emission from both constant and time evolving shocked fast winds blown by the central stars of planetary nebulae (PNs) and compare with observations. Using spherically symmetric numerical simulations with radiative cooling, we calculate ... More
Kinetic modeling of opinion formation of peoples via multiple political partiesMar 19 2014May 16 2014We investigate the opinion formation among the peoples and multiple political parties using the one dimensional relativistic Boltzmann-Vlasov equation for multi-components. A political party is constituted of politicians. The opinion formation depends ... More
Opinion formation with upper and lower boundsFeb 28 2014Nov 23 2015We investigate the opinion formation with upper and lower bounds. We formulate the binary exchange of opinions between two individuals, and effects of the self-thinking and political party using the relativistic Boltzmann-Vlasov type equation with the ... More
Quantized Coulomb branches of Jordan quiver gauge theories and cyclotomic rational Cherednik algebrasAug 02 2016Aug 10 2016We study quantized Coulomb branches of quiver gauge theories of Jordan type. We prove that the quantized Coulomb branch is isomorphic to the spherical graded Cherednik algebra in the unframed case, and is isomorphic to the spherical cyclotomic rational ... More
Dynamical Properties of Quasi-One-Dimensional Boson-Fermion Mixtures of Atoms in a Toroidal PotentialJan 07 2013We theoretically investigate quantum-mechanical dynamics of quasi-one-dimensional boson-fermion mixtures of atomic gases trapped in a toroidal potential, where effective inter-atomic interactions are tunable and affect the dynamics. We especially focus ... More
Thermal fluctuations of granular gas under HCS using two-point kinetic theoryFeb 21 2011Thermal fluctuations of the granular gas under the homogeneous cooling state (HCS) are estimated using two-point kinetic theory by Tsuge-Sagara. Thermal fluctuations of the elastic gas are modified for the granular gas by nonequilibrium moments, which ... More
Phenomenological understanding of aggregation and dispersion of chemotactic cellsOct 25 2011We present a simple model that describes the motion of a single chemotactic cell exposed to a traveling wave of the chemoattractant. The model incorporates two types of responses to stimulation by the chemoattractant, i.e., change in polarity and change ... More
Composite Accidental AxionsFeb 17 2016We present several models where the QCD axion arises accidentally. Confining gauge theories can generate axion candidates whose properties are uniquely determined by the quantum numbers of the new fermions under the Standard Model. The Peccei-Quinn symmetry ... More
A collective opinion formation model under Bayesian updating and confirmation biasFeb 16 2013Jun 21 2013We propose a collective opinion formation model with a so-called confirmation bias. The confirmation bias is a psychological effect with which, in the context of opinion formation, an individual in favor of an opinion is prone to misperceive new incoming ... More
Constructing Large-scale Low-latency Network from Small Optimal NetworksAug 31 2016The construction of large-scale, low-latency networks becomes difficult as the number of nodes increases. In general, the way to construct a theoretically optimal solution is unknown. However, it is known that some methods can construct suboptimal networks ... More
Possible Signatures of Ejecta-Companion Interaction in iPTF 13bvnApr 08 2015May 30 2015We investigate the possible effects of the supernova ejecta hitting the companion star in iPTF 13bvn, focusing on the observable features when it becomes visible. iPTF 13bvn is a type Ib supernova that may become the first case that its progenitor is ... More
Quantum corrections to the spin-independent cross section of the inert doublet dark matterJan 17 2015The inert Higgs doublet model contains a stable neutral boson as a candidate of dark matter. We calculate cross section for spin-independent scattering of the dark matter on nucleon. We take into account electroweak and scalar quartic interactions, and ... More
Quantum corrections to the spin-independent cross section in the inert Higgs doublet modelApr 29 2015May 12 2015The inert Higgs doublet model is an extension of the standard model with an extra scalar doublet. The extra doublet is $Z_2$ odd while all the other particles are $Z_2$ even, thus the model contains a dark matter candidate. It is known that the spin-independent ... More
Quantum Interference of Surface-Induced Friedel Oscillations Enhanced by Fermi-Surface Nesting in Layered ManganitesOct 19 2015Oct 20 2015Imbalance of Mn3+ and Mn4+ ions between surface and bulk in layered manganites is investigated on the basis of an orbital degenerate double-exchange model with surfaces. For two types of t2g spin structures, the number of Mn4+ ions on the surface is found ... More
Coarse geometric properties of the Hilbert geometryDec 18 2014We give a necessary and sufficient condition for the natural boundary of a Hilbert geometry to be a corona. In addition, we show that any Hilbert geometry is uniformly contractible and with bounded coarse geometry. As a consequence of these we see that ... More
Current-excited magnetization dynamics in narrow ferromagnetic wiresJun 21 2006We investigate the current-excited magnetization dynamics in a narrow ferromagnetic Permalloy wire by means of Lorentz microscopy, together with the results of simultaneous transport measurements. A detailed structural evolution of the magnetization is ... More
Development of a Method for Tissue Elasticity Imaging Using Tagged Magnetic Resonance ImagingJul 02 2016The purpose of this study was to develop a method for tissue elasticity imaging using tagged magnetic resonance imaging (MRI). First, we developed a cyclic pressure device that used air to remotely transmit the power to generate cyclic deformation in ... More
Five-body resonances of 8He using the complex scaling methodJun 10 2010Sep 07 2010The 0+ states of 8He are studied in a five-body 4He+n+n+n+n cluster model. Many-body resonances are treated on the correct boundary condition as Gamow states using the complex scaling method. The 0+_2 state of 8He is predicted as a five-body resonance ... More
Taming macroscopic jamming in transportation networksFeb 17 2015May 26 2015In transportation networks, a spontaneous jamming transition is often observed, e.g in urban road networks and airport networks. Because of this instability, flow distribution is significantly imbalanced on a macroscopic level. To mitigate the congestion, ... More
Measurement of the photonic de Broglie wavelength of biphotons generated by spontaneous parametric down-conversionSep 02 2001Feb 26 2002Using a basic Mach-Zehnder interferometer, we demonstrate experimentally the measurement of the photonic de Broglie wavelength of an entangled photon pair (a biphoton) generated by spontaneous parametric down-conversion. The observed interference manifests ... More
Relaxing a constraint on the number of messengers in a low-scale gauge mediationOct 20 2009Jan 21 2010We propose a mechanism for relaxing a constraint on the number of messengers in low-scale gauge mediation models. The Landau pole problem for the standard-model gauge coupling constants in the low-scale gauge mediation can be circumvented by using our ... More
Enhanced Diphoton Signal of the Higgs Boson and the Muon g-2 in Gauge Mediation ModelsAug 13 2012Jan 09 2013We study the diphoton signal of the Higgs boson in gauge mediated supersymmetry breaking models, which can explain both the Higgs boson mass of around 125 GeV and the result of the muon g-2 experiment. We consider two possible extensions of gauge mediation ... More
Neutrinoful UniverseApr 30 2014Jul 08 2014The Standard Model of particle physics fails to explain the important pieces in the standard cosmology, such as inflation, baryogenesis, and dark matter of the Universe. We consider the possibility that the sector to generate small neutrino masses is ... More
General condition of the Mott transition expressed with the density of stateJun 29 2009We have investigated a contribution of the density of state (DOS) to the Mott metal-insulator transition (MIT). The MIT condition is given by the DOS, which usually requires the complicated fundamental equations. To simplify the process, we have derived ... More
Self-consistent Calculation of the Sommerfeld EnhancementMar 04 2016Jun 28 2016A calculation of the Sommerfeld enhancement is presented and applied to the problem of s-wave non-relativistic dark matter annihilation. The difference from previous computations in the literature is that the effect of the underlying short-range scattering ... More
Discrimination of dark matter models in future experimentsNov 05 2014Nov 06 2014Phenomenological aspects of simple dark matter models are studied. We discuss ways to discriminate the dark matter models in future experiments. We find that the measurements of the branching fraction of the Higgs boson into two photons and the electric ... More
One-neutron removal strength of 7He into 6He using the complex scaling methodJul 03 2009Jul 23 2009We study the one-neutron removal strength of the 7He ground state, which provides us with the 6He-n component in 7He. The He isotopes are described on the basis of the 4He+Xn cluster model (X=1,2,3). The complex scaling method is applied to describe not ... More
Isocurvature Constraints and Anharmonic Effects on QCD Axion Dark MatterApr 03 2013Sep 26 2013We revisit the isocurvature density perturbations induced by quantum fluctuations of the axion field by extending a recently developed analytic method and approximations to a time-dependent scalar potential, which enables us to follow the evolution of ... More
Mass Splitting between Charged and Neutral Winos at Two-Loop LevelDec 25 2012Mar 27 2013The recent result of the higgs search at the LHC experiment has lead to more attention to the supersymmetric standard models with heavy sfermions. Among them, the models with the almost pure wino being the lightest supersymmetric particle (LSP) have been ... More
Extra Matters Decree the Relatively Heavy Higgs of Mass about 125 GeV in the Supersymmetric ModelDec 14 2011Feb 12 2012We show that the Higgs mass about 125 GeV is easily realized in supersymmetric model with extra matters, simultaneously explaining the anomaly in the muon anomalous magnetic moment and the dark matter density.
LHC Test of CDF $Wjj$ anomalyJul 26 2011Nov 25 2012We discuss a test of the CDF dijet anomaly at the LHC. The recent observed dijet mass peak at the CDF is well fitted by a new particle with a mass of around 150 GeV, which decays into two jets. In this paper, we focus on only $Wjj$ signal to avoid model ... More
A Possible Interpretation of CDF Dijet Mass Anomaly and its Realization in SupersymmetryApr 11 2011May 11 2011Recently, the CDF collaboration reports an anomaly in dijet mass distribution in association with a lepton and missing energy. We discuss a possibility that the origin of the lepton and missing energy comes not from a W boson but a new boson particle, ... More
Planetary Systems in Binaries. I. Dynamical ClassificationFeb 27 2008May 02 2008Many recent observational studies have concluded that planetary systems commonly exist in multiple-star systems. At least ~20% of the known extrasolar planetary systems are associated with one or more stellar companions. The orbits of stellar binaries ... More