total 167took 0.22s

Singular Kahler Potential and Heavy Top Quark in A Democratic Mass Matrix ModelJul 30 2003It is pointed out that heavy top quark mass can be attributed to a singular normalization of its kinetic term, in which rescaling into canonical one yields large top Yukawa coupling. We pursue this novel possibility in a democratic mass matrix model where ... More

Gravitational waves as a probe of extended scalar sectors with the first order electroweak phase transitionSep 28 2015Dec 13 2015We discuss spectra of gravitational waves which are originated by the strongly first order phase transition at the electroweak symmetry breaking, which is required for a successful scenario of electroweak baryogenesis. Such spectra are numerically evaluated ... More

Abundance of Cosmological Relics in Low-Temperature ScenariosMar 21 2006May 16 2006We investigate the relic density n_\chi of non-relativistic long-lived or stable particles \chi in cosmological scenarios in which the temperature T is too low for \chi to achieve full chemical equilibrium. The case with a heavier particle decaying into ... More

Vector WIMP MiracleFeb 27 2012May 25 2012Weakly interacting massive particle (WIMP) is well known to be a good candidate for dark matter, and it is also predicted by many new physics models beyond the standard model at the TeV scale. We found that, if the WIMP is a vector particle (spin one ... More

Synergy between measurements of the gravitational wave and the triple Higgs coupling in probing first order phase transitionApr 07 2016Jul 20 2016Probing the Higgs potential and new physics behind the electroweak symmetry breaking is one of the most important issues of particle physics. In particular, nature of electroweak phase transition is essential for understanding physics at the early Universe, ... More

Gravitational waves from first order electroweak phase transition in models with the $U(1)_X^{}$ gauge symmetryFeb 08 2018We consider a standard model extension equipped with a dark sector where the $U(1)_X^{}$ Abelian gauge symmetry is spontaneously broken by the dark Higgs mechanism. In this framework, we investigate patterns of the electroweak phase transition as well ... More

Proton Decay, Fermion Masses and Texture from Extra Dimensions in SUSY GUTsOct 19 2001May 05 2004In supersymmetry, there are gauge invariant dimension 5 proton decay operators which must be suppressed by a mass scale much larger than the Planck mass. It is natural to expect that this suppression should be explained by a mechanism that explains the ... More

U(1) Flavor Symmetry and Proton Decay in Supersymmetric Standard ModelMar 20 2002Jul 13 2002Issues of proton decay are examined in supersymmetric standard model with U(1) flavor symmetry. Dimension five proton-decay operators which arise generically are controlled by the flavor symmetry. We show that unlike the minimal supersymmetric SU(5) case ... More

Splitting Triplet and Doublet in Extra DimensionsApr 11 2001Apr 17 2001A novel mechanism to realize the triplet-doublet splitting in supersymmetric SU(5) grand unified theories is proposed in the framework of higher dimensional theories where chiral multiplets are localized due to kink configuration of a SU(5) singlet. An ... More

Phenomenological signatures of mixed complex scalar WIMP dark matterSep 21 2016Nov 09 2016We discuss phenomenological aspects of models whose scalar sector is extended by an isospin doublet scalar and a complex singlet scalar as an effective theory of supersymmetric models with mixed sneutrinos. In such models, the lighter of the mixed neutral ... More

The Thermal Abundance of Semi-Relativistic RelicsApr 20 2009Aug 11 2009Approximate analytical solutions of the Boltzmann equation for particles that are either extremely relativistic or non-relativistic when they decouple from the thermal bath are well established. However, no analytical formula for the relic density of ... More

Relic abundance of dark matter in the minimal universal extra dimension modelMay 26 2006We investigate the relic abundance of dark matter in the minimal universal extra dimension model including resonance processes by second Kaluza-Klein (KK) particles in all coannihilation processes. After including second KK resonance processes, the relic ... More

Constraints on the Very Early Universe from Thermal WIMP Dark MatterApr 12 2007Nov 16 2007We investigate the relic density n_\chi of non-relativistic long-lived or stable particles \chi in non-standard cosmological scenarios. We calculate the relic abundance starting from arbitrary initial temperatures of the radiation-dominated epoch, and ... More

Hadronic EDM Constraints on Orbifold GUTsMay 27 2005Oct 03 2005We point out that the null results of the hadronic electric dipole moment (EDM) searches constrain orbifold grand unified theories (GUTs), where the GUT symmetry and supersymmetry (SUSY) are both broken by boundary conditions in extra dimensions and it ... More

Thermal relic abundance of the lightest Kaluza-Klein particle in phenomenological universal extra dimension modelsNov 21 2016Universal extra dimension models with Kaluza-Klein parity provide us excellent candidates for dark matter. We consider phenomenological universal extra dimension models where the Kaluza-Klein (KK) mass spectrum is different from that of the minimal universal ... More

New Constraint on Squark Flavor Mixing from 199Hg Electric Dipole MomentNov 06 2003Dec 17 2003A new constraint is obtained on the CP-violating flavor mixing between the left-handed top scalar quark (\tilde{t}_L) and charm scalar quark (\tilde{c}_L), by considering a chargino loop contribution to chromo-electric dipole moment of strange quark, ... More

Phenomenological signatures of mixed complex scalar WIMP dark matterSep 21 2016We discuss phenomenological aspects of models whose scalar sector is extended by an isospin doublet scalar and a complex singlet scalar as an effective theory of supersymmetric models with mixed sneutrinos. In such models, the lighter of the mixed neutral ... More

Democratic (S)fermions and Lepton Flavor ViolationDec 12 2002The democratic approach to account for fermion masses and mixing is known to be successful not only in the quark sector but also in the lepton sector. Here we extend this ansatz to supersymmetric standard models, in which the K\"ahler potential obeys ... More

Large Supersymmetric Contribution to CP Asymmetry of B_d \to φK_S from Left-Handed Squark MixingMar 25 2004Apr 06 2004Supersymmetric contribution to the CP asymmetry of B_d \to \phi K_S is re-examined. It is emphasized that our analysis takes into account the recently found constraint from the mercury electric dipole moment, in addition to the well-known constraint from ... More

Phenomenological constraints on light mixed sneutrino dark matter scenariosMar 23 2015In supersymmetric models with Dirac neutrinos, the lightest sneutrino can be an excellent thermal dark matter candidate when the soft sneutrino trilinear parameter is large. We focus on scenarios where the mass of the mixed sneutrino is of the order of ... More

Relic Abundance of LKP Dark Matter in UED model including Effects of Second KK ResonancesAug 28 2005We reevaluate the thermal relic density of the Kaluza-Klein (KK) dark matter in universal extra dimension models. In particular, we consider the effect of the resonance caused by second KK particles on the density. We find that the annihilation cross ... More

Testing Minimal Universal Extra Dimensions Using Higgs Boson Searches at the LHCJul 03 2012Dec 13 2012Large Hadron Collider (LHC) searches for the SM Higgs boson provide a powerful limit on models involving Universal Extra Dimensions (UED) where the Higgs production is enhanced. We have evaluated all one-loop diagrams for Higgs production from gluon fusion ... More

Gravitational waves and Higgs boson couplings for exploring first order phase transition in the model with a singlet scalar fieldSep 01 2016We calculate the spectrum of gravitational waves originated from strongly first order electroweak phase transition in the extended Higgs model with a real singlet field. In order to calculate the bubble nucleation rate, we perform a two-field analysis ... More

Significant effects of second KK particles on LKP dark matter physicsFeb 07 2005Jun 17 2005We point out that Kaluza-Klein (KK) dark matter physics is drastically affected by second KK particles. In this work various interesting phenomena caused by the second KK modes are discussed. In particular, we reevaluate the annihilation cross section ... More

Higgs as a Probe of Supersymmetric Grand Unification with the Hosotani MechanismDec 29 2013Feb 19 2014The supersymmetric grand unified theory where the SU(5) gauge symmetry is broken by the Hosotani mechanism predicts the existence of adjoint chiral superfields whose masses are at the supersymmetry breaking scale. The Higgs sector is extended with the ... More

Hadronic EDMs in SUSY SU(5) GUTs with Right-handed NeutrinosJul 15 2004Dec 26 2004We discuss hadronic EDM constraints on the neutrino sector in the SUSY SU(5) GUT with the right-handed neutrinos. The hadronic EDMs are sensitive to the right-handed down-type squark mixings, especially between the second and third generations and between ... More

Indirect reach of heavy MSSM Higgs bosons by precision measurements at future lepton collidersMay 14 2015Sep 11 2015In the Minimal Supersymmetric Standard Model (MSSM), the bottom Yukawa coupling of the Higgs boson can considerably deviate from its Standard Model prediction due to non-decoupling effects. We point out that the ratio of the Higgs boson decay branching ... More

Conjugate Codes and Applications to CryptographyOct 23 2006A conjugate code pair is defined as a pair of linear codes such that one contains the dual of the other. The conjugate code pair represents the essential structure of the corresponding Calderbank-Shor-Steane (CSS) quantum code. It is argued that conjugate ... More

Constructive Conjugate Codes for Quantum Error Correction and CryptographyMar 28 2007Mar 29 2007A conjugate code pair is defined as a pair of linear codes either of which contains the dual of the other. A conjugate code pair represents the essential structure of the corresponding Calderbank-Shor-Steane (CSS) quantum error-correcting code. It is ... More

Lower Bounds on the Quantum Capacity and Highest Error Exponent of General Memoryless ChannelsDec 18 2001Jun 21 2002Tradeoffs between the information rate and fidelity of quantum error-correcting codes are discussed. Quantum channels to be considered are those subject to independent errors and modeled as tensor products of copies of a general completely positive linear ... More

Exponential lower bound on the highest fidelity achievable by quantum error-correcting codesSep 21 2001Jun 21 2002On a class of memoryless quantum channels which includes the depolarizing channel, the highest fidelity of quantum error-correcting codes of length n and rate R is proven to be lower bounded by 1-exp[-nE(R)+o(n)] for some function E(R). The E(R) is positive ... More

Teleportation and entanglement distillation in the presence of correlation among bipartite mixed statesFeb 07 2003The teleportation channel associated with an arbitrary bipartite state denotes the map that represents the change suffered by a teleported state when the bipartite state is used instead of the ideal maximally entangled state for teleportation. This work ... More

A Lower Bound on the Quantum Capacity of Channels with Correlated ErrorsJan 14 2002Jun 21 2002The highest fidelity of quantum error-correcting codes of length n and rate R is proven to be lower bounded by 1 - exp [-n E(R)+ o(n)] for some function E(R) on noisy quantum channels that are subject to not necessarily independent errors. The E(R) is ... More

Concatenated Quantum Codes Constructible in Polynomial Time: Efficient Decoding and Error CorrectionOct 23 2006Aug 19 2008A method for concatenating quantum error-correcting codes is presented. The method is applicable to a wide class of quantum error-correcting codes known as Calderbank-Shor-Steane (CSS) codes. As a result, codes that achieve a high rate in the Shannon ... More

X-ray Fluctuations from the Slim DiskMay 08 2000The responses of perturbations added into the optically thick, advection-dominated accretion disk (ADAD), what we call the slim disk (SD), are investigated through numerical simulations. Although it is proposed that the SD is thermally stable, I find ... More

Concatenated Conjugate CodesOct 23 2006Oct 31 2006A conjugate code pair is defined as a pair of linear codes either of which contains the dual of the other. A conjugate code pair represents the essential structure of the corresponding Calderbank-Shor-Steane (CSS) quantum code. It is known that conjugate ... More

Constraints on the temperature inhomogeneity in quasar accretion discs from the ultraviolet-optical spectral variabilityFeb 27 2015The physical mechanisms of the quasar ultraviolet (UV)-optical variability are not well understood despite the long history of observations. Recently, Dexter & Agol presented a model of quasar UV-optical variability, which assumes large local temperature ... More

Nonequilibrium process in the $σ$ model and chemical relaxation time in a homogeneous pionic gasAug 08 1996In a homogeneous pionic gas system, chemical nonequilibrium process is considered to understand its effect in the expansion processes that are realized immediately after heavy ion collisions. The chemical relaxation time is calculated by incorporating ... More

The Minimum Number of Rotations About Two Axes for Constructing an Arbitrary Fixed RotationDec 31 2013Jun 30 2014For any pair of three-dimensional real unit vectors $\hat{m}$ and $\hat{n}$ with $|\hat{m}^{\rm T} \hat{n}| < 1$ and any rotation $U$, let $N_{\hat{m},\hat{n}}(U)$ denote the least value of a positive integer $k$ such that $U$ can be decomposed into a ... More

Information Rates Achievable with Algebraic Codes on Quantum Discrete Memoryless ChannelsJul 19 2002Dec 30 2002The highest information rate at which quantum error-correction schemes work reliably on a channel, which is called the quantum capacity, is proven to be lower bounded by the limit of the quantity termed coherent information maximized over the set of input ... More

An Exposition of a Result in "Conjugate Codes for Secure and Reliable Information Transmission"Jan 12 2010An elementary proof of the attainability of random coding exponent with linear codes for additive channels is presented. The result and proof are from Hamada (Proc. ITW, Chendu, China, 2006), and the present material explains the proof in detail for those ... More

Notes on the Fidelity of Symplectic Quantum Error-Correcting CodesNov 01 2003Nov 24 2003Two observations are given on the fidelity of schemes for quantum information processing. In the first one, we show that the fidelity of a symplectic (stabilizer) code, if properly defined, exactly equals the `probability' of the correctable errors for ... More

Reliability of Calderbank-Shor-Steane Codes and Security of Quantum Key DistributionAug 05 2003Jul 23 2004After Mayers (1996, 2001) gave a proof of the security of the Bennett-Brassard 1984 (BB84) quantum key distribution protocol, Shor and Preskill (2000) made a remarkable observation that a Calderbank-Shor-Steane (CSS) code had been implicitly used in the ... More

Structural resolvent estimates and derivative nonlinear Schrodinger equationsJan 26 2011A refinement of uniform resolvent estimate is given and several smoothing estimates for Schrodinger equations in the critical case are induced from it. The relation between this resolvent estimate and radiation condition is discussed. As an application ... More

A counterexample for boundedness of pseudo-differential operators on modulation spacesJan 25 2007We prove that pseudo-differential operators with symbols in the class $S_{1,\delta}^0$ ($0<\delta<1$) are not always bounded on the modulation space $M^{p,q}$ ($q\neq2$).

Odd-particle number random phase approximation and extensions: Applications to particle and hole states around $^{16}$OJan 10 2013The hole-state random phase approximation (hRPA) and the particle-state random phase approximation (pRPA) for systems like odd $A$ nuclei are discussed. These hRPA and pRPA are formulated based on the Hartree-Fock ground state. An extension of hRPA and ... More

Higgs Boson Mass and Electroweak-Gravity Hierarchy from Dynamical Gauge-Higgs Unification in the Warped SpacetimeMar 02 2005Apr 14 2005Dynamical electroweak symmetry breaking by the Hosotani mechanism in the Randall-Sundrum warped spacetime is examined, relations among the W-boson mass (m_W), the Kaluza-Klein mass scale (M_{KK}), and the Higgs boson mass (m_H) being derived. It is shown ... More

Optimal constants and extremisers for some smoothing estimatesJun 22 2012Nov 11 2012We establish new results concerning the existence of extremisers for a broad class of smoothing estimates of the form $\|\psi(|\nabla|) \exp(it\phi(|\nabla|)f \|_{L^2(w)} \leq C\|f\|_{L^2}$, where the weight $w$ is radial and depends only on the spatial ... More

Recent progress in smoothing estimates for evolution equationsFeb 07 2014This paper is a survey article of results and arguments from several of authors' papers, and it describes a new approach to global smoothing problems for dispersive and non-dispersive evolution equations based on ideas of comparison principle and canonical ... More

Fragmentation of electric dipole strength in N=82 isotonesDec 06 2011Fragmentation of the dipole strength in the N=82 isotones 140Ce, 142Nd and 144Sm is calculated using the second random-phase approximation (SRPA). In comparison with the result of the random-phase approximation (RPA), the SRPA provides the additional ... More

On Hadamard's global inverse function theorem (On global inversion of homogeneous maps)May 25 2013Oct 08 2014Hadamard's global inverse theorem provides conditions for a function to be globally invertible on Rn. In this note we show that the conditions are robust enough for the conclusion to hold even if we relax the conditions by removing the assumption at a ... More

Boundedness properties of pseudo-differential operators and Calderón-Zygmund operators on modulation spacesJan 29 2007In this paper, we study the boundedness of pseudo-differential operators with symbols in $S_{\rho,\delta}^m$ on the modulation spaces $M^{p,q}$. We discuss the order $m$ for the boundedness $\mathrm{Op}(S_{\rho,\delta}^m) \subset \calL(M^{p,q}(\R^n))$ ... More

Operator ordering in Two-dimensional N=1 supersymmetry with curved manifoldAug 21 2007We investigate an operator ordering problem in two-dimensional N=1 supersymmetric model which consists of n real superfields. There arises an operator ordering problem when the target space is curved. We have to fix the ordering in quantum operator properly ... More

Weighted Sobolev L2 estimates for a class of Fourier integral operatorsNov 19 2007In this paper we develop elements of the global calculus of Fourier integral operators in $R^n$ under minimal decay assumptions on phases and amplitudes. We also establish global weighted Sobolev $L^2$ estimates for a class of Fourier integral operators ... More

Global regularity properties for a class of Fourier integral operatorsOct 12 2015While the local $L^p$-boundedness of nondegeneral Fourier integral operators is known from the work of Seeger, Sogge and Stein, not so many results are available for the global boundedness on $L^p(\mathbb R^n)$. In this paper we give a sufficient condition ... More

The inclusion relation between Sobolev and modulation spacesSep 05 2010Sep 07 2010The inclusion relations between the $L^p$-Sobolev spaces and the modulation spaces is determined explicitly. As an application, mapping properties of unimodular Fourier multiplier $e^{i|D|^\alpha}$ between $L^p$-Sobolev spaces and modulation spaces are ... More

Role of Ca off-centering in tuning the ferroelectric phase transitions in Ba(Zr,Ti)O3 systemMar 02 2015We here report the substitution effects of the smaller Ca for the bulky Ba in (Ba1-xCax)(Ti1-yZry)O3 perovskite oxides for two systems (Ba1-xCax)TiO3 with y=0 and (Ba1-xCax)(Ti0.9Zr0.1)O3 with y=0.1. Ca off-centering was found to play a critical role ... More

Smoothing estimates for evolution equations via canonical transforms and comparisonDec 11 2006Jun 08 2007The paper describes a new approach to global smoothing problems for dispersive and non-dispersive evolution equations based on the global canonical transforms and the underlying global microlocal analysis. For this purpose, the Egorov-type theorem is ... More

Trace theorems: critical cases and best constantsAug 15 2012The purpose of this paper is to present the critical cases of the trace theorems for the restriction of functions to closed surfaces, and to give the asymptotics for the norms of the traces under dilations of the surface. We also discuss the best constants ... More

Permutation test for dendrograms and its application to the analysis of mental lexiconsMar 12 2014A novel type of permutation tests for dendrogram data is studied with respect to two types of metrics for measuring the difference between dendrograms. First, the Frobenius norm is used, and we prove the consistency and efficiency of the permutation tests. ... More

Unusual Dielectric Relaxation in Lightly Doped n-Type Rhombohedral BaTi0.85Zr0.15O3:Ta Ferroelectric CeramicsMar 10 2005The dielectric properties of tantalum doped BaTi0.85Zr0.15O3 were investigated. The conventional solid state reaction method was used to make the ceramic samples. The composition was close to the pinch point of the three structure phase transitions in ... More

Thermodynamics in Density-Functional Theory and Force TheoremsJul 02 2003Jul 17 2003The density-functional (DF) theory provides a simple method for calculating the properties of an interacting system under an external potential by associating it with a corresponding non-interacting system. Here, we find some relations in this non-interacting ... More

Partial Pressures in Liquid Mixtures and Osmotic PressuresJun 21 2012Feb 12 2015When an osmotic system is composed of 1- and 0-species particles, which are confined to the volumes, $V\equiv V_{\rm a}+V_{\rm b}$ and $V_{\rm b}$, by the wall pressures, $P_1^{{\rm w}_{\rm a}}$ and $P_0^{{\rm w}_{\rm b}}$, respectively, we obtain a law ... More

Comparison of estimates for dispersive equationsFeb 19 2008This paper describes a new comparison principle that can be used for the comparison of space-time estimates for dispersive equations. In particular, results are applied to the global smoothing estimates for several classes of dispersive partial differential ... More

A remark on fractional integrals on modulation spacesJul 03 2007In this paper, we give the necessary and sufficient conditions for the boundedness of fractional integral operators on the modulation spaces.

Progress in Many Body Theory with the Equation of Motion method. Time dependent Density Matrix meets Self-Consistent RPA. Applications to solvable ModelsMar 28 2016The Bogoliubov-Born-Green-Kirkwood-Yvon or Time-Dependent Density Matrix (TDDM) hierarchy of equations for higher density matrices is truncated at the three body level in approximating the three body correlation function by a quadratic form of two body ... More

Smoothing estimates for non-dispersive equationsAug 03 2015This paper describes an approach to global smoothing problems for non-dispersive equations based on ideas of comparison principle and canonical transformation established in authors' previous paper, where dispersive equations were treated. For operators ... More

Operator ordering and Classical soliton path in Two-dimensional N=2 supersymmetry with Kahler potentialAug 03 2005Oct 25 2005We investigate a 2-dimensional N=2 supersymmetric model which consists of n chiral superfields with Kahler potential. When we define quantum observables, we are always plagued by operator ordering problem. Among various ways to fix the operator order, ... More

Criteria for Bochner's extension problemFeb 05 2008A necessary and sufficient condition for the resolution of the weak extension problem is given. This criterion is applied to also give a criterion for the solvability of the classical Bochner's extension problem in the $L^p$-category. The solution of ... More

Smoothing properties of inhomogeneous equations via canonical transformsFeb 25 2013The paper describes a new approach to global smoothing problems for inhomogeneous dispersive evolution equations based on an idea of canonical transformation. In our previous papers, we introduced such a method to show global smoothing estimates for homogeneous ... More

On the Gauss-Chern-Bonnet theorem for the noncommutative 4-sphereApr 05 2016We construct a differential calculus over the noncommutative 4-sphere in the framework of pseudo-Riemannian calculi, and show that for every metric in a conformal class of perturbations of the round metric, there exists a unique metric and torsion-free ... More

Optimal forward and reverse estimates of Morawetz and Kato-Yajima type with angular smoothing indexSep 20 2014For the solution of the free Schr\"odinger equation, we obtain the optimal constants and characterise extremisers for forward and reverse smoothing estimates which are global in space and time, contain a homogeneous and radial weight in the space variable, ... More

Electron and nuclear pressures in electron-nucleus mixturesMar 04 2003Jan 26 2007It is shown for an electron-nucleus mixture that the electron and nuclear pressures are defined clearly and simply by the virial theorem; the total pressure of this system is a sum of these two pressures. The electron pressure is different from the conventional ... More

Enhancement of non-resonant dielectric cloaks using anisotropic compositesJun 14 2013Jul 25 2013Cloaking techniques conceal objects by controlling the flow of electromagnetic waves to minimize scattering. Herein, the effectiveness of homogenized anisotropic materials in non-resonant dielectric multilayer cloaking is studied. Because existing multilayer ... More

Testing Forest-Isomorphism in the Adjacency List ModelApr 28 2014We consider the problem of testing if two input forests are isomorphic or are far from being so. An algorithm is called an $\varepsilon$-tester for forest-isomorphism if given an oracle access to two forests $G$ and $H$ in the adjacency list model, with ... More

A smoothing property of Schrodinger equations in the critical caseMay 28 2004In this paper a global smoothing property of Schrodinger equations is established in the critical case in dimensions two and higher. It is shown that the critical smoothing estimate is attained if the smoothing operator has some structure. This structure ... More

Truncation scheme of time-dependent density-matrix approachDec 13 2013A truncation scheme of the Bogoliubov-Born-Green-Kirkwood-Yvon hierarchy for reduced density matrices, where a three-body density matrix is approximated by the antisymmetrized products of two-body density matrices, is proposed. This truncation scheme ... More

Riemannian curvature of the noncommutative 3-sphereMay 27 2015Nov 18 2015In order to investigate to what extent the calculus of classical (pseudo-)Riemannian manifolds can be extended to a noncommutative setting, we introduce pseudo-Riemannian calculi of modules over noncommutative algebras. In this framework, it is possible ... More

Global L2-boundedness theorems for a class of Fourier integral operatorsNov 13 2003The local $L^2$-mapping property of Fourier integral operators has been established in H\"ormander \cite{H} and in Eskin \cite{E}. In this paper, we treat the global $L^2$-boundedness for a class of operators that appears naturally in many problems. As ... More

Ferroelectricity in Silver Perovskite OxidesAug 30 2011There are two silver perovskite oxides: AgNbO3 and AgTaO3. AgNbO3 has a noncentrosymmetric group of Pmc21 at room temperature with a ferri-electric ordering of polarization. Such a ferri-electric state with small polarization can be changed into a ferroelectric ... More

Slim Disk Model for Narrow-Line Seyfert 1 GalaxiesMay 08 2000We argue that both the extreme soft X-ray excess and the large-amplitude variability of Narrow-Line Seyfert 1 galaxies (NLS1s) can be explained in the framework of the slim disk model. When the disk luminosity approaches the Eddington luminosity, the ... More

Dark matter in UED : the role of the second KK levelDec 12 2010We perform a complete calculation of the relic abundance of the KK-photon LKP in the universal extra dimension model including all coannihilation channels and all resonances. We show that the production of level 2 particles which decay dominantly into ... More

A matrix subadditivity inequality for f(A+B) and f(A)+f(B)Feb 16 2007Let f be a non-negative concave function on the positive half-line. Let A and B be two positive matrices. Then, for all symmetric norms, || f(A+B) || is less than || f(A)+f(B) ||. When f is operator concave, this was proved by Ando and Zhan. Our method ... More

Proton acceleration beyond 100 EeV by an oblique shock wave in the jet of 3C 273Aug 05 2004We estimate the highest energy of proton diffusively accelerated by shock in knot A1 of the jet in luminous nearby quasar 3C 273. Referring to the recent polarization measurements using very long baseline interferometry (VLBI), we consider the shock propagation ... More

Entropy solutions of the Euler equations for isothermal relativistic fluidsJan 01 2007We investigate the initial-value problem for the relativistic Euler equations governing isothermal perfect fluid flows, and generalize an approach introduced by LeFloch and Shelukhin in the non-relativistic setting. We establish the existence of globally ... More

Filamentary jets as a cosmic-ray "Zevatron"Nov 04 2004Feb 07 2008Strong, anisotropic turbulence reflecting magnetized filaments is considered, to model the diffusive acceleration of particles by shock waves in active galactic nucleus jets. We address that at knot A of the nearby M87 jet, the shock involving the filamentary ... More

Transitive X-ray spectrum and PeV gamma-ray cutoff in the M87 jet: Electron "Pevatron"Nov 30 2006Dec 20 2006We propose a modified version of the X-ray spectral index and an intrinsic cutoff frequency of inverse Compton radiation from the brightest knot of the M87 jet, in conjunction with an application of the new conceptions of injection and diffusive shock ... More

Self-Collimation and Magnetic Field Generation of Astrophysical JetsApr 03 2002A novel model for collimation and transport of electron-positron-ion jets is presented. Analytical results show that the filamentary structures can be sustained by self-induced toroidal magnetic fields permeating through the filaments, whose widths significantly ... More

On Exact Polytropic Equilibria of Self-Gravitating Gaseous and Radiative Systems: Their Application to Molecular Cloud CondensationApr 24 2003We propose a novel mathematical method to construct an exact polytropic sphere in self-gravitating hydrostatic equilibrium, improving the non-linear Poisson equation. The central boundary condition for the present equation requires a ratio of gas pressure ... More

Particle Diffusion and Acceleration by Shock Wave in Magnetized Filamentary TurbulenceOct 26 2005We expand the off-resonant scattering theory for particle diffusion in magnetized current filaments that can be typically compared to astrophysical jets, including active galactic nucleus jets. In a high plasma beta region where the directional bulk flow ... More

Extremisers for the trace theorem on the sphereSep 20 2014We find all extremisers for the trace theorem on the sphere. We also provide a sharp extension for functions belonging to certain Sobolev spaces with angular regularity.

Magnetic and Critical Properties of Alternating Spin Chain with S=1/2,1 in Magnetic FieldsNov 05 1996We study an integrable spin chain with an alternating array of spins S=1/2, 1 in external magnetic fields using the Bethe ansatz exact solution. The calculated magnetization possesses a cusp structure at a critical magnetic field H=H_{C}, at which the ... More

Higgs Phenomenology of Minimal Universal Extra DimensionsJan 26 2012The minimal model of Universal Extra Dimensions (MUED) is briefly reviewed. We explain how the cross-sections for Higgs production via gluon fusion and decay into two photons are modified, relative the the Standard Model (SM) values, by KK particles running ... More

Differentially Private Analysis of OutliersJul 24 2015Jul 27 2015This paper investigates differentially private analysis of distance-based outliers. The problem of outlier detection is to find a small number of instances that are apparently distant from the remaining instances. On the other hand, the objective of differential ... More

Monte-Carlo Simulation of Domain-Wall Network in Two-dimensional Extended Supersymmetric TheorySep 19 2001Sep 20 2001We will show that 2-dimensional N=2-extended supersymmetric theory can have solitonic solution using the Hamilton-Jacobi method of classical mechanics. Then it is shown that the Bogomol'nyi mass bound is saturated by these solutions and triangular mass ... More

On the $L^2$-boundedness of pseudo-differential operators and their commutators with symbols in $α$-modulation spacesJul 03 2007In this paper, we consider the $L^2$-boundedness of pseudo-differential operators with symbols in $\alpha$-modulation spaces.

Spin and chirality orderings of the one-dimensional Heisenberg spin glass with the long-range power-law interactionSep 26 2006The ordering of the one-dimensional Heisenberg spin glass interacting via the long-range power-law interaction is studied by Monte Carlo simulations. Particular attention is paid to the possible occurrence of the ``spin-chirality decoupling'' for appropriate ... More

Hamilton-Jacobi Solution to Soliton Paths and Triangular Mass Relation in Two-dimensional Extended Supersymmetric TheoryAug 28 2001D=2,N=2 generalized Wess-Zumino theory is investigated by the dimensional reduction from D=4,N=1 theory. For each solitonic configuration (i,j) the classical static solution is solved by the Hamilton-Jacobi method of equivalent one-dimensional classical ... More

Scintillation characteristics of undoped and Cu+-doped Li2B4O7 single crystalsMar 12 2015Scintillation characteristics of undoped and Cu+-doped lithium tetraborate Li2B4O7 (LTB) were studied including optical transmittance, photoluminescence, radioluminescence for X- and gamma-rays, alpha/gamma ratio, and decay kinetics. The total time-integrated ... More

Trace ideals for pseudo-differential operators and their commutators with symbols in $α$-modulation spacesOct 02 2007In this paper, we consider the trace property of pseudo-differential operators with symbols in $\alpha$-modulation spaces.