Results for "Kazuhiro Nawa"

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Anisotropic Field-Induced Gap in Quasi-One-Dimensional Antiferromagnet KCuMoO$_4$(OH)Sep 12 2017We investigated magnetic and thermodynamic properties of $S$ = 1/2 quasi-one-dimensional antiferromagnet KCuMoO$_4$(OH) through single crystalline magnetization and heat capacity measurements. At zero field, it behaves as a uniform $S$ = 1/2 Heisenberg ... More
Orbital Arrangements and Magnetic Interactions in the Quasi-One-Dimensional Cuprates ACuMoO_4(OH) (A = Na, K)May 20 2015A new spin-1/2 quasi-one-dimensional antiferromagnet KCuMoO_4(OH) is prepared by the hydrothermal method. The crystal structures of KCuMoO_4(OH) and the already-known Na-analogue, NaCuMoO_4(OH), are isotypic, comprising chains of Cu^{2+} ions in edge-sharing ... More
One-dimensionalization by Geometrical Frustration in the Anisotropic Triangular Lattice of the 5d Quantum Antiferromagnet Ca3ReO5Cl2Apr 12 2019We report on the emergence of antiferromagnetic spin chains from two-dimensionally aligned spins on the anisotropic triangular lattice (ATL) in the insulating calcium rhenium oxychloride Ca3ReO5Cl2. The compound contains Re6+ ions each with one unpaired ... More
Anisotropic spin fluctuations in the quasi one-dimensional frustrated magnet LiCuVO_4Jul 09 2013We report results of NMR experiments on a single crystal of the quasi one-dimensional frustrated magnet LiCuVO_4. The NMR spectra of ^7Li and ^{51}V nuclei indicate a helical spin order in a magnetic field of 4 T with the helical spin plane perpendicular ... More
Collinear Spin-density-wave Order and Anisotropic Spin Fluctuations in the Frustrated $J_1$--$J_2$ Chain Magnet NaCuMoO$_4$(OH)Nov 08 2017The phase diagram of the quasi-one-dimensional magnet NaCuMoO$_4$(OH) is established through single-crystal NMR and heat-capacity measurements. The $^{23}$Na and $^1$H NMR experiments indicate a spiral and a collinear spin-density-wave (SDW) order below ... More
Dynamics of Bound Magnon Pairs in the Quasi-One-Dimensional Frustrated Magnet LiCuVO_4Feb 27 2017Oct 24 2017We report on the dynamics of the spin-1/2 quasi-one-dimensional frustrated magnet LiCuVO$\mathrm{_4}$ measured by nuclear spin relaxation in high magnetic fields 10--34 T, in which the ground state has spin-density-wave order. The spin fluctuations in ... More
Luttinger-liquid Parameter of Hubbard Chain and Hubbard LadderDec 08 1999We study the Luttinger-liquid parameter $K_{\rho}$ of the Hubbard chain and the Hubbard ladder models by the ordinary perturbation method combined with the Luttinger-liquid relation. According to the Luttinger-liquid relation, the critical exponent $K_{\rho}$ ... More
A possible phase diagram of a t-J ladder modelJan 09 1996We investigate a t-J ladder model by numerical diagonalization method. By calculating correlation functions and assuming the Luttinger liquid relation, we obtained a possible phase diagram of the ground state as a function of J/t and electron density ... More
Metabolic networks are almost nonfractal: A comprehensive evaluationJul 17 2014Jul 30 2014Network self-similarity or fractality are widely accepted as an important topological property of metabolic networks; however, recent studies cast doubt on the reality of self-similarity in the networks. Therefore, we perform a comprehensive evaluation ... More
Optimal Weighting Scheme in Redshift-space Power Spectrum Analysis and a Prospect for Measuring the Cosmic Equation of StateAug 06 2002Jun 12 2003We develop a useful formula for power spectrum analysis for high and intermediate redshift galaxy samples, as an extension of the work by Feldman, Kaiser & Peacock (1994). An optimal weight factor, which minimizes the errors of the power spectrum estimator, ... More
q-series and L-functions related to half-derivatives of the Andrews--Gordon identityMar 20 2003May 10 2003Studied is a generalization of Zagier's q-series identity. We introduce a generating function of L-functions at non-positive integers, which is regarded as a half-differential of the Andrews--Gordon q-series. When q is a root of unity, the generating ... More
Hyperbolicity of Partition Function and Quantum GravityAug 02 2001We study a geometry of the partition function which is defined in terms of a solution of the five-term relation. It is shown that the 3-dimensional hyperbolic structure or Euclidean AdS_3 naturally arises in the classical limit of this invariant. We discuss ... More
Hyperbolic Structure Arising from a Knot InvariantMay 28 2001We study the knot invariant based on the quantum dilogarithm function. This invariant can be regarded as a non-compact analogue of Kashaev's invariant, or the colored Jones invariant, and is defined by an integral form. The 3-dimensional picture of our ... More
Flux Phase in Bilayer $t-J$ Model: Time-Reversal Symmetry Breaking Surface State without Spontaneous Magnetic FieldFeb 10 2015May 13 2015We study surface states of high-$T_C$ cuprate superconductor YBCO using the bilayer $t-J$ model. Calculations based on the Bogoliubov de Gennes method show that a flux phase that breaks time-reversal symmetry (${\cal T}$) may arise near a (110) surface ... More
Quarkonium production at collider energies in Small-$x$ formalismNov 02 2016Apr 27 2017I present a short review of recent studies of quarkonium production in proton-proton and proton-nucleus collisions at collider energies in Small-$x$ formalism.
All exceptional surgeries on alternating knots are integral surgeriesAug 15 2008Oct 14 2008We show that all exceptional surgeries on hyperbolic alternating knots in the 3-sphere are integral surgeries.
Operator Relations for Gravitational Form FactorsMay 06 2019The form factors for the hadron matrix element of the QCD energy-momentum tensor not only describe the coupling of the hadron with a graviton as the ``gravitational form factors'', but also serve as unique quantities for describing the shape inside the ... More
Unconditional construction of K3 surfaces over finite fields with given L-function in large characteristicDec 16 2016Nov 23 2018We give an unconditional construction of K3 surfaces over finite fields with given L-function, up to finite extensions of the base fields, under some mild restrictions on the characteristic. Previously, such results were obtained by Taelman assuming semistable ... More
Finiteness of Brauer groups of K3 surfaces in characteristic 2Apr 20 2017Jan 04 2018For a K3 surface over a field of characteristic 2 which is finitely generated over its prime subfield, we prove that the cokernel of the natural map from the Brauer group of the base field to that of the K3 surface is finite modulo the 2-primary torsion ... More
Existence of supersingular reduction for families of K3 surfaces with large Picard number in positive characteristicNov 15 2016Jul 29 2017We study non-isotrivial families of $K3$ surfaces in positive characteristic $p$ whose geometric generic fibers satisfy $\rho\geq21-2h$ and $h\geq3$, where $\rho$ is the Picard number and $h$ is the height of the formal Brauer group. We show that, under ... More
Michel parameters for $τ$ decays $τ\rightarrow lν\barν~(l=e,~μ)$ in a general two Higgs doublet model with $μ-τ$ flavor violationJul 15 2016In a general two Higgs doublet model (2HDM), the anomaly of muon anomalous magnetic moment (muon g-2) can be explained by $\mu-\tau$ flavor violating Yukawa couplings, motivated by the recent CMS excess in Higgs boson decay $h\rightarrow \mu \tau$. We ... More
On the Continuum and Lattice Formulations of N=4 D=3 Twisted Super Yang-MillsOct 30 2007Nov 02 2007Employing a twisted superspace with eight supercharges, we describe an off-shell formulation of N=4 D=3 twisted super Yang-Mills in the continuum spacetime which underlies the recent proposal of N=4 D=3 twisted super Yang-Mills on a lattice (arXiv:0707.3533[hep-lat]). ... More
Transformation Formula of the "2nd" Order Mock Theta FunctionApr 04 2006We give a transformation formula for the ``2nd order'' mock theta function which was recently proposed in connection with the quantum invariant for the Seifert manifold.
Mock (False) Theta Functions as Quantum InvariantsJun 29 2005We show a correspondence between the SU(2) Witten--Reshetikhin--Turaev invariant for the Seifert manifold M(p,q,r) and Ramanujan's mock theta functions.
Quantum Invariant, Modular Form, and Lattice PointsSep 08 2004We study the Witten--Reshetikhin--Turaev SU(2) invariant for the Seifert manifold with 4-singular fibers. We define the Eichler integrals of the modular forms with half-integral weight, and we show that the invariant is rewritten as a sum of the Eichler ... More
Ginzburg-Landau Equations for Coexistent States of Superconductivity and Antiferromagnetism in t-J modelAug 13 2012Dec 09 2012Ginzburg-Landau (GL) equations for the coexistent state of superconductivity and antiferromagnetism are derived microscopically from the t-J model with extended transfer integrals. GL equations and the GL free energy, which are obtained based on the slave-boson ... More
Proximity effects near the interface between d-wave superconductors and ferro/antiferromagnetsJun 16 1999Aug 22 1999We study the proximity effects near the interface between a d-wave superconductor (S) and a ferromagnet (F) or an antiferromagnet (AF). The S-side (F and AF-side) is described by the attractive (repulsive) Hubbard model, and the Bogoliubov de Gennes equation ... More
Evolution of the Blue Luminosity-to-Baryon Mass Ratio of Clusters of GalaxiesJan 31 2000We derive the ratio of total blue luminosity to total baryon mass, LB/Mb, for massive (Mgas at the Abell radius is \ge 1 \times 10^{13} h^{-2.5} \Msolar) clusters of galaxies up to z \simeq 1 from the literature. Twenty-two clusters in our sample are ... More
Flux phase as possible time-reversal symmetry breaking surface states of high-$T_C$ cuprate superconductorsJan 14 2014Apr 07 2014At a (110) surface of a $d_{x^2-y-2}$-wave superconductor, superconducting order is strongly suppressed. In such a situation, ordered states that are forbidden in the bulk may arise. This problem is studied for high-$T_C$ cuprate superconductors by treating ... More
Seiberg-Witten prepotential for E-string theory and random partitionsMar 13 2012We find a Nekrasov-type expression for the Seiberg-Witten prepotential for the six-dimensional non-critical E_8 string theory toroidally compactified down to four dimensions. The prepotential represents the BPS partition function of the E_8 strings wound ... More
Seiberg-Witten prepotential for E-string theory and global symmetriesJul 24 2012Sep 05 2012We obtain Nekrasov-type expressions for the Seiberg-Witten prepotential for the six-dimensional (1,0) supersymmetric E-string theory compactified on T^2 with nontrivial Wilson lines. We consider compactification with four general Wilson line parameters, ... More
Spontaneous Magnetic Field near a Time-Reversal Symmetry Broken Surface State of YBCOApr 16 2019Spatial distributions of spontaneous magnetic fields near a surface of cuprate high-$T_C$ superconductor YBCO with broken time-reversal symmetry are calculated using the Ginzburg-Landau theory derived from the $t-J$ model. It is found that the magnetic ... More
A functional relation for Tornheim's double zeta functionsNov 07 2012In this paper, we generalize the partial fraction decomposition which is fundamental in the theory of multiple zeta values, and prove a relation between Tornheim's double zeta functions of three complex variables. As applications, we give new integral ... More
Three-loop formula for quark and gluon contributions to the QCD trace anomalyNov 19 2018Nov 21 2018In the QCD energy-momentum tensor $T^{\mu\nu}$, the terms that contribute to physical matrix elements are expressed as the sum of the gauge-invariant quark part and gluon part. Each part undergoes the renormalization due to the interactions among quarks ... More
Transverse-spin gluon distribution functionAug 08 2014We introduce the spin-operator representation for the gluon as well as quark distribution functions as nucleon matrix element of the gauge-invariant bilocal light-cone operators in QCD. To identify the relevant spin operators for quarks and gluons in ... More
Riemannian optimal model reduction of stable linear systemsMar 05 2018Aug 02 2018In this paper, we develop a method for solving the problem of minimizing the $H^2$ error norm between the transfer functions of original and reduced systems on the set of stable matrices and two Euclidean spaces. That is, we develop a method for identifying ... More
Optimal leader selection and demotion in leader-follower multi-agent systemsFeb 19 2018We consider leader-follower multi-agent systems that have many leaders, defined on any connected weighted undirected graphs, and address the leader selection and demotion problems. The leader selection problem is formulated as a minimization problem for ... More
Triplon band splitting and topologically protected edge states in the dimerized antiferromagnetOct 21 2018The search for topological insulators has been actively promoted in the field of condensed matter physics for further development in energy-efficient information transmission and processing. In this context, recent studies have revealed that not only ... More
Exact Lattice Supersymmetry at Large NMay 28 2008Jul 24 2008Employing a novel type of non-commutative product in the Dirac-Kahler twisted superspace on a lattice, we formulate a field theoretically rigid framework of extended supersymmetry on a lattice. As a first example of this treatment, we calculate one-loop ... More
Generalized Volume Conjecture and the A-Polynomials -- the Neumann-Zagier Potential Function as a Classical Limit of Quantum InvariantApr 05 2006We study quantum invariant Z(M) for cusped hyperbolic 3-manifold M. We construct this invariant based on oriented ideal triangulation of M by assigning to each tetrahedron the quantum dilogarithm function, which is introduced by Faddeev in studies of ... More
Asymptotics of the Colored Jones Polynomial and the A-PolynomialJul 21 2004We reveal a relationship between the colored Jones polynomial and the A-polynomial for twist knots. We demonstrate that an asymptotics of the $N$-colored Jones polynomial in large $N$ gives the potential function, and that the A-polynomial can be computed. ... More
On the Quantum Invariant for the Brieskorn Homology SpheresMay 10 2004Jan 01 2005We study an exact asymptotic behavior of the Witten-Reshetikhin-Turaev invariant for the Brieskorn homology spheres $\Sigma(p_1,p_2,p_3)$ by use of properties of the modular form following a method proposed by Lawrence and Zagier. Key observation is that ... More
Baxter Equation for Quantum Discrete Boussinesq EquationFeb 19 2001Studied is the Baxter equation for the quantum discrete Boussinesq equation. We explicitly construct the Baxter $\mathcal{Q}$ operator from a generating function of the local integrals of motion of the affine Toda lattice field theory, and show that it ... More
On the Quantum Invariant for the Spherical Seifert ManifoldApr 28 2005May 08 2006We study the Witten--Reshetikhin--Turaev SU(2) invariant for the Seifert manifold $S^3/\Gamma$ where $\Gamma$ is a finite subgroup of SU(2). We show that the WRT invariants can be written in terms of the Eichler integral of the modular forms with half-integral ... More
Effect of Band Structure on the Symmetry of Superconducting StatesFeb 05 2001Feb 06 2001Effects of the band structure on the symmetry of superconducting (SC) states are studied. For a square lattice system with a nearest-neighbor attractive interaction, SC states with various symmetries are found by changing the band structure, or, the shape ... More
A reduced BPS index of E-stringsAug 15 2014Dec 03 2014We study the BPS spectrum of E-strings in a situation where the global E_8 symmetry is broken down to D_4 + D_4 by a certain twist. We find that the refined BPS index in this setup serves as a reduced BPS index of E-strings, which gives a novel trigonometric ... More
Topological string amplitudes for the local half K3 surfaceNov 16 2011We study topological string amplitudes for the local half K3 surface. We develop a method of computing higher genus amplitudes along the lines of the direct integration formalism, making full use of the Seiberg-Witten curve expressed in terms of modular ... More
Habitat variability does not generally promote metabolic network modularity in flies and mammalsDec 09 2015The evolution of species habitat range is an important topic over a wide range of research fields. In higher organisms, habitat range evolution is generally associated with genetic events such as gene duplication. However, the specific factors that determine ... More
Optimal Graph LaplacianFeb 19 2018Jun 19 2018This paper provides a construction method of the nearest graph Laplacian to a matrix identified from measurement data of graph Laplacian dynamics that include biochemical systems, synchronization systems, and multi-agent systems. We consider the case ... More
Exceptional surgeries on components of two-bridge linksJul 03 2011In this paper, we give a complete classification of exceptional Dehn surgeries on a component of a hyperbolic two-bridge link in the 3-sphere.
On a new harmonic heat flow with the reverse Hölder inequalitiesJan 10 2014This paper first proposes a new approximate scheme to construct a harmonic heat flow $u$ between a parabolic cylinder to a sphere. Y.Chen and M.Struwe have proved an existence and discussed a partial regularity of harmonic heat flows by using Ginzburg-Landau ... More
On the supersingular reduction of K3 surfaces with complex multiplicationSep 30 2017Nov 29 2018We study the good reduction modulo p of K3 surfaces with complex multiplication. If a K3 surface with complex multiplication has good reduction, we calculate the Picard number and the height of the formal Brauer group of the reduction. Moreover, if the ... More
Pairs of boundary slopes with small differencesJun 29 2013Mar 10 2014We show that, for any positive real number, there exists a knot in the 3-sphere admitting a pair of boundary slopes whose difference is at most the given number.
Difference equation of the colored Jones polynomial for torus knotMar 14 2004We prove that the N-colored Jones polynomial for the torus knot T_{s,t} satisfies the second order difference equation, which reduces to the first order difference equation for a case of T_{2,2m+1}. We show that the A-polynomial of the torus knot can ... More
Simple Construction of Elliptic Boundary K-MatrixJul 24 1995We give the infinite-dimensional representation for the elliptic $ K $-operator satisfying the boundary Yang-Baxter equation. By restricting the functional space to finite-dimensional space, we construct the elliptic $ K $-matrix associated to Belavin's ... More
Measuring the Density Fluctuation From the Cluster Gas Mass FunctionJan 27 1997We investigate the gas mass function of clusters of galaxies to measure the density fluctuation spectrum on cluster scales. The baryon abundance confined in rich clusters is computed from the gas mass function and compared with the mean baryon density ... More
Lepton-Flavour-Violation in SUSY Models with and without R-parityAug 09 2000We discuss Lepton-Flavour-Violating phenomena such as $\mu \to e \gamma$, $\mu \to eee$, and $\mu \to e$ conversion in nuclei in SUSY models with and without R-parity. We stress that experimental searches for all the LFV processes are important to distinguish ... More
q-differential operator representation of the quantum superalgebra Uq(sl(M+1|N+1))Dec 30 1996A representation of the quantum superalgebra Uq(sl(M+1|N+1)) is constructed based on the q-differential operators acting on the coherent states parameterized by coordinates. These coordinates correspond to the local ones of the flag manifold. This realization ... More
Hamiltonian Reduction of Super Osp(1,2)} and Sl(2,1) Kac-Moody AlgebrasOct 16 1991Dec 14 1991We present the Wakimoto construction of the super OSp(1,2) and SL(2,1) Kac-Moody algebras and the free field representation of the corresponding WZW models. After imposing suitable constraints, we can lead the Feigin-Fuchs representation of Virasoro algebras ... More
On Free Boson Representations of the Quantum Affine Algebra $U_q(\widehat{\sl}_2)$Dec 05 1992A boson representation of the quantum affine algebra $U_q(\widehat{\sl}_2)$ is realized based on the Wakimoto construction. We discuss relations with the other boson representations.
An f-chromatic spanning forest of edge-colored complete bipartite graphsJun 13 2011In 2001, Brualdi and Hollingsworth proved that an edge-colored balanced complete bipartite graph Kn,n with a color set C = {1,2,3,..., 2n-1} has a heterochromatic spanning tree if the number of edges colored with colors in R is more than |R|^2 /4 for ... More
Cosmetic surgeries and non-orientable surfacesSep 01 2012By considering non-orientable surfaces in the surgered manifolds, we show that the 10/3- and -10/3-Dehn surgeries on the 2-bridge knot $9_{27} = S(49,19)$ are not cosmetic, i.e., they give mutually non-homeomorphic manifolds. The knot is unknown to have ... More
On the maximal number and the diameter of exceptional surgery slope setsOct 04 2011Feb 20 2012Concerning the set of exceptional surgery slopes for a hyperbolic knot, Lackenby and Meyerhoff proved that the maximal cardinality is 10 and the maximal diameter is 8. Their proof is computer-aided in part, and both bounds are achieved simultaneously. ... More
Heegaard gradient of Seifert fibered 3-manifoldNov 06 2002Oct 27 2003The infimal Heegaard gradient of a compact 3-manifold was defined and studied by Marc Lackenby in an approach toward the well-known virtually Haken conjecture. As instructive examples, we consider Seifert fibered 3-manifolds, and show that a Seifert fibered ... More
On a time-discrete approach to solving Navier-Stokes systemsAug 11 2014We present a new scheme for solving Navier-Stokes systems. This is inspired by material differentiation and combined with discrete Morse semi-flow. The solution has the first energy inequality, we set some assumption though. This result crucially does ... More
Quasiparticle properties and the dynamics of high-density nuclear matterOct 18 1993The energy spectrum of nucleons in high-density nuclear matter is investigated in the framework of relativistic meson-nucleon many-body theory, employing the $1/N$ expansion method. The coupling of the nucleon with the particle-hole excitations in the ... More
Quantum Knot Invariant for Torus Link and Modular FormsMay 20 2003Oct 22 2003We consider an asymptotic expansion of Kashaev's invariant or the colored Jones function for the torus link T(2,2m). We shall give q-series identity related to these invariants, and show that the invariant is regarded as a limit of q being N-th root of ... More
Separation of Variables in BC-type Gaudin MagnetJun 07 1995The integrable system is introduced based on the Poisson $ rs $-matrix structure. This is a generalization of the Gaudin magnet, and in SL(2) case isomorphic to the generalized Neumann model. The separation of variables is discussed for both classical ... More
Skein Theory and Topological Quantum Registers: Braiding Matrices and Topological Entanglement Entropy of Non-Abelian Quantum Hall StatesSep 15 2007We study topological properties of quasi-particle states in the non-Abelian quantum Hall states. We apply a skein-theoretic method to the Read--Rezayi state whose effective theory is the SU(2)_K Chern--Simons theory. As a generalization of the Pfaffian ... More
Quantum Invariants, Modular Forms, and Lattice Points IIApr 05 2006We study the SU(2) Witten--Reshetikhin--Turaev invariant for the Seifert fibered homology spheres with M-exceptional fibers. We show that the WRT invariant can be written in terms of (differential of) the Eichler integrals of modular forms with weight ... More
Integral non-hyperbolike surgeriesOct 04 2004Feb 05 2005It is shown that a hyperbolic knot in the 3-sphere admits at most nine integral surgeries yielding 3-manifolds which are reducible or whose fundamental groups are not infinite word-hyperbolic.
Quick Brown Fox in Formal LanguagesDec 27 2015Feb 11 2016Given a finite alphabet $\Sigma$ and a deterministic finite automaton on $\Sigma$, the problem of determining whether the language recognized by the automaton contains any pangram is \NP-complete. Various other language classes and problems around pangrams ... More
Flux Phase as a Possible Ordered State in t-J ModelOct 14 2013Dec 13 2013In high-Tc cuprate superconductors, violation of time-reversal symmetry (${\cal T}$) has been observed experimentally. In order to explain this phenomenon, we consider a flux phase in the t-J model. The flux phase has a free energy higher than that of ... More
Flux Phase in Bilayer $t-J$ ModelSep 02 2014Nov 18 2014In order to study the time-reversal symmetry (${\cal T}$) breaking near a (110) surface of a high-$T_C$ cuprate YBCO, we consider the flux phase in a bilayer $t-J$ model. Although the stable solution in the bulk is the $d_{x^2-y-2}$-wave superconducting ... More
Quarkonium production at collider energies in Small-$x$ formalismNov 02 2016I present a short review of recent studies of quarkonium production in proton-proton and proton-nucleus collisions at collider energies in Small-$x$ formalism.
BPS index and 4d N=2 superconformal field theoriesMar 30 2016Jul 08 2016We study the BPS index for the four-dimensional rank-one N=2 superconformal field theories H_0, H_1, H_2, E_6, E_7, E_8. We consider compactifications of the E-string theory on T^2 in which these theories arise as low energy limits. Using this realization ... More
Metabolic network modularity arising from simple growth processesSep 04 2012Metabolic networks consist of linked functional components, or modules. The mechanism underlying metabolic network modularity is of great interest not only to researchers of basic science but also to those in fields of engineering. Previous studies have ... More
A generalization of heterochromatic graphsFeb 23 2011In 2006, Suzuki, and Akbari & Alipour independently presented a necessary and sufficient condition for edge-colored graphs to have a heterochromatic spanning tree, where a heterochromatic spanning tree is a spanning tree whose edges have distinct colors. ... More
On operator relations for gravitational form factors of a spin-0 hadronJun 27 2018Aug 10 2018The gravitational form factors for a hadron, the form factors for the hadron matrix element of the QCD energy-momentum tensor, not only describe the coupling of the hadron with a graviton, but also serve as unique quantities for describing the shape inside ... More
Higher twist light-cone distribution amplitudes of vector mesons in QCDFeb 21 1999We present a systematic study of twist-3 light-cone distribution amplitudes of vector mesons in QCD, which is based on conformal expansion. A complete set of distribution amplitudes is constructed for \rho, \omega, K^* and \phi mesons, which satisfies ... More
$(g,f)$-Chromatic spanning trees and forestsSep 27 2018A heterochromatic (or rainbow) graph is an edge-colored graph whose edges have distinct colors, that is, where each color appears at most once. In this paper, I propose a $(g,f)$-chromatic graph as an edge-colored graph where each color $c$ appears at ... More
Degenerate ground state in the classical pyrochlore antiferromagnet Na$_3$Mn(CO$_3$)$_2$ClOct 11 2018In an ideal classical pyrochlore antiferromagnet without perturbations, an infinite degeneracy at a ground state leads to absence of a magnetic order and spin-glass transition. Here we present Na$_3$Mn(CO$_3$)$_2$Cl as a new candidate compound where classical ... More
A flux tube model for glueballsMay 09 2003We calculate the mass spectrum and the decay widths of glueballs in the flux tube model. The glueball is assumed to be a closed flux tube. The breathing motion and the rotational motion are investigated using the WKB approximation. The calculated spectra ... More
Uniqueness and nondegeneracy of ground states to nonlinear scalar field equations involving the Sobolev critical exponent in their nonlinearities for high frequenciesJan 26 2018May 05 2019The study of the uniqueness and nondegeneracy of ground state solutions to semilinear elliptic equations is of great importance because of the resulting energy landscape and its implications for the various dynamics. In [AIKN3], semilinear elliptic equations ... More
Spin-current absorption by inhomogeneous spin-orbit couplingApr 10 2012Oct 03 2012We investigate the spin-current absorption induced by an inhomogeneous spin-orbit coupling due to impurities in metals. We consider the system with spin currents driven by the electric field or the spin accumulation. The resulting diffusive spin currents, ... More
NaCuMoO_4(OH) as a Candidate Frustrated J_1-J_2 Chain Quantum MagnetSep 04 2014In a frustrated J_1-J_2 chain with the nearest-neighbor ferromagnetic interaction J_1 and the next-nearest-neighbor antiferromagnetic interaction J_2, novel magnetic states such as a spin-nematic state are theoretically expected. However, they have been ... More
Structural anomalies and short-range magnetic correlations in the orbitally degenerated system Sr$_2$VO$_4$Jul 15 2015We report on the electronic ground state of a layered perovskite vanadium oxide Sr$_2$VO$_4$ studied by the combined use of synchrotron radiation x-ray diffraction (SR-XRD) and muon spin rotation/relaxation ($\mu$SR) techniques, where $\mu$SR measurements ... More
Phase diagrams of electronic state on One Dimensional d-p ModelJul 10 1994We investigate the one-dimensional(1D) d-p model, simulating a Cu-O linear chain with strong Coulomb repulsion, by using the numerical diagonalization method. Using the Luttinger liquid theory, we obtained phase diagrams of the ground state on $U_d-U_{pd}$ ... More
Neutrino Masses and Lepton-Flavor Violation in Supersymmetric Models with lopsided Froggatt-Nielsen chargesDec 25 2000We analyze in detail lepton-flavor violation (LFV) in the charged-lepton sector such as $\mu \to e \gamma$, $\tau \to \mu \gamma$, $\mu \to eee$ and the $\mu \to e$ conversion in nuclei, within the framework of supersymmetric models with lopsided Froggatt--Nielsen ... More
On the origin of the dressing phase in N=4 Super Yang-MillsMar 20 2007Feb 12 2008We derive the phase factor proposed by Beisert, Eden and Staudacher for the S-matrix of planar N=4 Super Yang-Mills, from the all-loop Bethe ansatz equations without the dressing factor. We identify a configuration of the Bethe roots, from which the closed ... More
A large spin limit of strings on AdS_5 x S^5 in a non-compact sectorJul 25 2006Dec 20 2006We study the scaling law of the energy spectrum of classical strings on AdS_5 x S^5, in particular, in the SL(2) sector for large S (AdS spin) and fixed J (S^1 \subset S^5 spin). For any finite gap solution, we identify the limit in which the energy exhibits ... More
On the Additional Symmetry; Many-Body Problem Related to the KP HierarchyFeb 04 1994Nonlinear integrable equations, such as the KdV equation, the Boussinesq equation and the KP equation, have the close relation with many-body problem. The solutions of such equations are the same as the restricted flows of the classical Calogero model, ... More
Nested structure acquired through simple evolutionary processMay 23 2011Nested structure, which is non-random, controls cooperation dynamics and biodiversity in plant-animal mutualistic networks. This structural pattern has been explained in a static (non-growth) network models. However, evolutionary processes might also ... More
Dielectric Environment Effect on Carrier Mobility of Graphene Double-Layer StructureJul 23 2013We have theoretically studied the dielectric environment effect on the charged-impurity-limited carrier mobility of graphene double-layer structure (GDLS) on the basis of the Boltzmann transport theory. In this system, two graphene layers are separated ... More
Phenomenological Aspects of a Direct-transmission Model of Dynamical Supersymmetry Breaking with the Gravitino Mass $m_{3/2} < 1~\KEV$Aug 17 1997Jun 19 1998We analyze a direct-transmission model of dynamical SUSY breaking previously proposed. In the model the gravitino mass is naturally smaller than $1~\KEV$, which is required from the standard cosmology. We find that there are many distinguishable features ... More
Testing gravity with halo density profiles observed through gravitational lensingJan 19 2012May 09 2012We present a new test of the modified gravity endowed with the Vainshtein mechanism with the density profile of a galaxy cluster halo observed through gravitational lensing. A scalar degree of freedom in the galileon modified gravity is screened by the ... More
Twisted elliptic genus for K3 and Borcherds productDec 27 2011May 08 2012We further discuss the relation between the elliptic genus of K3 surface and the Mathieu group M24. We find that some of the twisted elliptic genera for K3 surface, defined for conjugacy classes of the Mathieu group M24, can be represented in a very simple ... More
Time-dependent Hartree-Fock calculations for multinucleon transfer processes in $^{40,48}$Ca+$^{124}$Sn, $^{40}$Ca+$^{208}$Pb, and $^{58}$Ni+$^{208}$Pb reactionsMar 03 2013Jun 27 2013Multinucleon transfer processes in heavy-ion reactions at energies slightly above the Coulomb barrier are investigated in a fully microscopic framework of the time-dependent Hartree-Fock (TDHF) theory. Transfer probabilities are calculated from the TDHF ... More
Symmetry energy at subnuclear densities deduced from nuclear massesFeb 23 2010Apr 19 2010We examine how nuclear masses are related to the density dependence of the symmetry energy. Using a macroscopic nuclear model we calculate nuclear masses in a way dependent on the equation of state of asymmetric nuclear matter. We find by comparison with ... More
The symmetry energy at subnuclear densities and nuclei in neutron star crustsSep 15 2006Oct 03 2006We examine how the properties of inhomogeneous nuclear matter at subnuclear densities depend on the density dependence of the symmetry energy. Using a macroscopic nuclear model we calculate the size and shape of nuclei in neutron star matter at zero temperature ... More