Results for "Tomoya Naito"

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Coulomb Energy Density Functionals for Nuclear Systems: Recent Studies of Coulomb Exchange and Correlation FunctionalsJul 10 2019The Coulomb exchange and correlation energy density functionals for electron systems are applied to nuclear systems. It is found that the exchange functionals in the generalized gradient approximation provide agreements with the exact-Fock energy with ... More
Functional-renormalization-group aided density-functional analysis for the correlation energy of the two-dimensional homogeneous electron gasDec 03 2018The functional-renormalization-group aided density-functional theory (FRG-DFT) is applied to the two-dimensional homogeneous electron gas (2DHEG). The correlation energy of the 2DHEG is derived as a function of the Wigner-Seitz radius $ r_{\rm s} $ directly. ... More
Application of Coulomb energy density functional for atomic nuclei: Case studies of local density approximation and generalized gradient approximationDec 18 2017Apr 23 2018We test the Coulomb exchange and correlation energy density functionals of electron systems for atomic nuclei in the local density approximation (LDA) and the generalized gradient approximation (GGA). For the exchange Coulomb energies, it is found that ... More
Improvement of Functionals in Density Functional Theory by the Inverse Kohn-Sham Method and Density Functional Perturbation TheoryDec 21 2018We propose the way to improve energy density functionals in the density functional theory based on the combination of the inverse Kohn-Sham method and the density functional perturbation theory. As benchmark calculations, we reproduce the theoretical ... More
Construction of Negatively Curved Cubic Carbon Crystals via Standard RealizationsJan 09 2016We constructed physically stable sp2 negatively curved cubic carbon structures which reticulate a Schwarz P-like surface. The method for constructing such crystal structures is based on the notion of the standard realization of abstract crystal lattices. ... More
Semiparametric density estimation by local L_2-fittingJun 25 2004This article examines density estimation by combining a parametric approach with a nonparametric factor. The plug-in parametric estimator is seen as a crude estimator of the true density and is adjusted by a nonparametric factor. The nonparametric factor ... More
String operations on rational Gorenstein spacesJan 09 2013F\'{e}lix and Thomas developed string topology of Chas and Sullivan on simply-connected Gorenstein spaces. In this paper, we prove that the degree shifted homology of the free loop space of a simply-connected ${\mathbb Q}$-Gorenstein space with rational ... More
A model for the Whitehead product in rational mapping spacesJun 21 2011We describe the Whitehead products in the rational homotopy group of a connected component of a mapping space in terms of the Andr\'{e}-Quillen cohomology. As a consequence, an upper bound for the Whitehead length of a mapping space is given.
First-principles calculation of scattering potentials of Si-Ge and Sn-Ge dimers on Ge(001) surfacesNov 01 2012Feb 08 2013The scattering potential of the defects on Ge(001) surfaces is investigated by first-principles methods. The standing wave in the spatial map of the local density of states obtained by wave function matching is compared to the image of the differential ... More
Even-odd oscillation of conductance of 5{\it d} metal atomic nanowiresMar 27 2008May 06 2008The electron-transport properties of single-row monoatomic nanowires made of 5$d$ elements are examined by first-principles calculations based on the density functional theory. We found that oscillation patterns with a period longer than two-atom length ... More
Volume function over a trivially valued fieldMay 14 2019We introduce an adelic Cartier divisor over a trivially valued field and discuss the bigness of it. For bigness, we give the integral representation of the arithmetic volume and prove the existence of limit of it. Moreover, we show that the arithmetic ... More
On the finite element approximation for non-stationary saddle-point problemsSep 03 2017In this paper, we present a numerical analysis of the hydrostatic Stokes equations, which are linearization of the primitive equations describing the geophysical flows of the ocean and the atmosphere. The hydrostatic Stokes equations can be formulated ... More
Energy dissipative numerical scheme for gradient flows of planar curves using discrete partial derivatives and B-spline curvesOct 10 2016In this paper, we develop an energy dissipative numerical scheme for gradient flows of planar curves, such as the curvature flow and the elastic flow. Our study presents a general framework for solving such equations. To discretize time, we use a similar ... More
Rescaled Perturbation TheoryOct 29 2010Dec 27 2010A non-perturbative method which can go beyond the weak coupling perturbation theory is introduced. Essential idea is to formulate a set of exact differential equations as a function of the coupling strength $g$. Unlike other resummation in which information ... More
The expectation value of the metric operator with respect to Gaussian weave state in loop quantum gravityDec 28 2002Nov 07 2003Loop Quantum Gravity is the major candidate of quantum gravity. It is interesting to consider its continuum limit, which corresponds to the classical limit. We consider the Gaussian weave state, which describes a semi-classical picture. We calculate the ... More
First-Principles Study on Leakage Current through Si/SiO$_2$ InterfaceDec 15 2008May 04 2009The relationship between the presence of defects at the stacking structure of the Si/SiO$_2$ interface and leakage current is theoretically studied by first-principles calculation. I found that the leakage current through the interface with dangling bonds ... More
Extended double shuffle relations and the generating function of triple zeta values of any fixed weightApr 18 2012Mar 09 2013Extended double shuffle relations for multiple zeta values are obtained by the fact that any product of regularized multiple zeta values has two different representations, and the case of two-fold product is considered in general. In this paper, we give ... More
Identities involving cyclic sums of regularized multiple zeta values each of depth less than $5$Feb 09 2015In this paper, we give identities involving cyclic sums of regularized multiple zeta values of depth less than $5$. As a corollary, we present two kinds of extensions of Hoffman's theorem for symmetric sums of multiple zeta values for this case.
Some restricted sum formulas for double zeta valuesOct 30 2012We give some restricted sum formulas for double zeta values whose arguments satisfy certain congruence conditions modulo 2 or 6, and also give an application to identities showed by Ramanujan for sums of products of Bernoulli numbers with a gap of 6.
Dynamical Mass Generation of Vector Mesons from QCD Trace AnomalyJun 17 2013Sep 06 2013Mass formulas for the light-vector mesons written in terms of the gluon condensate i.e., the trace anomaly in quantum chromodynamics (QCD), are derived on the basis of finite energy QCD sum rules. We utilize sum rules with $s^n$ and $s^{n+1/2}$ weights, ... More
The Entire Cyclic Cohomology of Noncommutative 2-ToriSep 10 2007May 14 2010Our aim in this paper is to compute the entire cyclic cohomology of noncommutative 2-tori. First of all, we clarify their algebraic structure of noncommutative 2-tori as a $F^*$-algebra, according to the idea of Elliott-Evans. Actually, they are the inductive ... More
Weighted sums with two parameters of multiple zeta values and their formulasDec 12 2011A typical formula of multiple zeta values is the sum formula which expresses a Riemann zeta value as a sum of all multiple zeta values of fixed weight and depth. Recently weighted sum formulas, which are weighted analogues of the sum formula, have been ... More
Coulomb exchange functional with generalized gradient approximation for self-consistent Skyrme Hartree-Fock calculationsOct 05 2018Feb 14 2019We perform the self-consistent Skyrme Hartree-Fock calculation with the Coulomb exchange functional in the form of generalized gradient approximation (GGA). It is found that the Perdew-Burke-Ernzerhof GGA (PBE-GGA) Coulomb exchange functional is able ... More
Use of the generating function to generalize the sum formula for quadruple zeta valuesMar 04 2015Nov 06 2017In the present paper, we prove an identity for the generating function of the quadruple zeta values. Taking homogeneous parts on both sides of the identity and substituting appropriate values for the variables, we obtain the sum formula for quadruple ... More
Hom-Poisson-Nijenhuis structures on Hom-Lie algebroids and Hom-Dirac structures on Hom-Courant algebroidsJul 11 2019In this paper, we develop the theory of Hom-Lie algebroids, Hom-Lie bialgebroids and Hom-Courant algebroids introduced by Cai, Liu and Sheng. Specifically, we introduce the notions of Hom-Poisson, Hom-Nijenhuis and Hom-Poisson-Nijenhuis structures on ... More
Generators for Vector Spaces Spanned by Double Zeta Values with Even WeightFeb 12 2008Apr 26 2014Let $\mathcal{DZ}_k$ be the $\mathbb{Q}$-vector space spanned by double zeta values with weight $k$, and $\mathcal{DM}_k$ be its quotient space divided by the space $\mathcal{PZ}_k$ spanned by the zeta value $\zeta(k)$ and products of two zeta values ... More
Use of the generating function to generalize the sum formula for quadruple zeta valuesMar 04 2015Oct 20 2015In the present paper, we prove an identity for the generating function of the quadruple zeta values. Taking homogeneous parts on both sides of the identity and substituting appropriate values for the variables, we obtain the sum formula for quadruple ... More
A parameterized generalization of the sum formula for quadruple zeta valuesOct 30 2012We give a parameterized generalization of the sum formula for quadruple zeta values. The generalization has four parameters, and is invariant under a cyclic group of order four. By substituting special values for the parameters, we also obtain weighted ... More
Congruence identities of regularized multiple zeta values involving a pair of index setsApr 20 2014Riemann zeta values are generalized to multiple zeta values (MZVs) by use of nested sums, and MZVs are generalized to regularized multiple zeta values (RMZVs) by regularization of divergent infinite series. In the present paper, we prove congruence identities ... More
Identity involving symmetric sums of regularized multiple zeta-star valuesNov 06 2017Apr 09 2018An identity involving symmetric sums of regularized multiple zeta-star values of harmonic type was proved by Hoffman. In this paper, we prove an identity of shuffle type. We use Bell polynomials appearing in the study of set partitions to prove the identity. ... More
Multiple pattern classification by sparse subspace decompositionJul 30 2009Aug 04 2009A robust classification method is developed on the basis of sparse subspace decomposition. This method tries to decompose a mixture of subspaces of unlabeled data (queries) into class subspaces as few as possible. Each query is classified into the class ... More
Mirkovic-Vilonen polytopes lying in a Demazure crystal and an opposite Demazure crystalJun 19 2008Oct 24 2008We give a necessary and sufficient condition for an MV polytope $P$ in a highest weight crystal to lie in an arbitrary fixed Demazure crystal (resp., opposite Demazure crystal), in terms of the lengths of edges along a path through the 1-skeleton of $P$ ... More
Lakshmibai-Seshadri paths of level-zero weight shape and one-dimensional sums associated to level-zero fundamental representationsFeb 20 2006We give interpretations of energy functions and (classically restricted) one-dimensional sums associated to tensor products of level-zero fundamental representations of quantum affine algebras in terms of Lakshmibai-Seshadri paths of level-zero weight ... More
Numerical studies of the optimization of the first eigenvalue of the heat diffusion in inhomogeneous mediaAug 22 2014Apr 22 2015In this paper, we study optimization of the first eigenvalue of the heat equation with spatially nonuniform conductivity on a bounded domain under several constraints for the conductivity. We consider this problem in various boundary conditions and various ... More
Approximation of the Schwinger--Dyson and the Bethe--Salpeter Equations and Chiral Symmetry of QCDMay 08 1998May 09 1998The Bethe--Salpeter equation for the pion in chiral symmetric models is studied with a special care to consistency with low-energy relations. We propose a reduction of the rainbow Schwinger--Dyson and the ladder Bethe--Salpeter equations with a dressed ... More
Conformal change of Riemannian metrics and biharmonic mapsJan 30 2013Jan 29 2014For the reduction ordinary differential equation due to Baird and Kamissoko \cite{BK} for biharmonic maps from a Riemannian manifold $(M^m,g)$ into another one $(N^n,h)$, we show that this ODE has no global positive solution for every $m\geq 5$. On the ... More
A modification of the Anderson-Mirkovic conjecture for Mirkovic-Vilonen polytopes in types B and CNov 01 2007Feb 12 2008We give an explicit description of the (lowering) Kashiwara operators on Mirkovi\'c-Vilonen polytopes in types $B$ and $C$, which provides a simple method for generating Mirkovi\'c-Vilonen polytopes inductively. This description can be thought of as a ... More
Path Model for a Level Zero Extremal Weight Module over a Quantum Affine AlgebraOct 30 2002Nov 06 2002We give a path model for a level zero extremal weight module over a quantum affine algebra. By using this result, we prove a branching rule for an extremal weight module with respect to a Levi subalgebra. Furthermore, we also show a decomposition rule ... More
Growth and Properties of Superconducting MgB2 Thin FilmsFeb 12 2004This review article describes the developments over the last 30 months in the thin film growth and junction fabrication of superconducting MgB2, including a brief summary the chemistry and physics of MgB2.
A combinatorial formula expressing periodic $R$-polynomialsMar 09 2016In 1980, Lusztig introduced the periodic Kazhdan-Lusztig polynomials, which are conjectured to have important information about the characters of irreducible modules of a reductive group over a field of positive characteristic, and also about those of ... More
Asymptotics for penalized additive B-spline regressionApr 27 2011This paper is concerned with asymptotic theory for penalized spline estimator in bivariate additive model. The focus of this paper is put upon the penalized spline estimator obtained by the backfitting algorithm. The convergence of the algorithm as well ... More
Newton-Okounkov convex bodies of Schubert varieties and polyhedral realizations of crystal basesMar 04 2016A Newton-Okounkov convex body is a convex body constructed from a projective variety with a valuation on its homogeneous coordinate ring; this is deeply connected with representation theory. For instance, the Littelmann string polytopes and the Feigin-Fourier-Littelmann-Vinberg ... More
Crystal structure of the set of Lakshmibai-Seshadri paths of a level-zero shape for an affine Lie algebraOct 02 2005Let $\lambda = \sum_{i \in I_{0}} m_{i} \varpi_{i}$, with $m_{i} \in \mathbb{Z}_{\ge 0}$ for $i \in I_{0}$, be a level-zero dominant integral weight for an affine Lie algebra $\mathfrak{g}$ over $\mathbb{Q}$, where the $\varpi_{i}$, $i \in I_{0}$, are ... More
Asymptotics and practical aspects of testing normality with kernel methodsFeb 08 2019This paper is concerned with testing normality in a Hilbert space based on the maximum mean discrepancy. Specifically, we discuss the behavior of the test from two standpoints: asymptotics and practical aspects. Asymptotic normality of the test under ... More
Asymptotics for penalized splines in generalized additive modelsAug 20 2012This paper discusses asymptotic theory for penalized spline estimators in generalized additive models. The purpose of this paper is to establish the asymptotic bias and variance as well as the asymptotic normality of the penalized spline estimators proposed ... More
Low Microwave Surface Resistance in NdBa2Cu3O7-d Films Grown by Molecular Beam EpitaxyOct 19 2004We report the growth of NdBa2Cu3O7-d films on (100) MgO substrate by Molecular Beam Epitaxy (MBE). Large area NdBa2Cu3O7-d films with homogeneous superconducting properties were grown by precise control of stoichiometry and the optimisation of growth ... More
In-situ growth of superconducting MgB2 thin films by molecular beam epitaxyOct 11 2002The in-situ growth of superconducting MgB2 thin films was examined from various perspectives. The paper discusses (1) growth temperature, (2) the effect of excess Mg, (3) the effect of residual gas during growth, (4) the effect of in-situ annealing, (5) ... More
Prediction of multivariate responses with a select number of principal componentsJul 25 2008This paper proposes a new method and algorithm for predicting multivariate responses in a regression setting. Research into classification of High Dimension Low Sample Size (HDLSS) data, in particular microarray data, has made considerable advances, but ... More
A combinatorial formula expressing periodic $R$-polynomialsMar 09 2016Aug 09 2018In 1980, Lusztig introduced the periodic Kazhdan-Lusztig polynomials, which are conjectured to have important information about the characters of irreducible modules of a reductive group over a field of positive characteristic, and also about those of ... More
Tensor product multiplicities for crystal bases of extremal weight modules over quantum infinite rank affine algebras of types $B_{\infty}$, $C_{\infty}$, and $D_{\infty}$Mar 12 2010Using Lakshmibai-Seshadri paths, we give a combinatorial realization of the crystal basis of an extremal weight module of integral extremal weight over the quantized universal enveloping algebra associated to the infinite rank affine Lie algebra of type ... More
Timesaving Double-Grid Method for Real-Space Electronic-Structure CalculationsApr 08 1999Jun 10 1999We present a simple and efficient technique in ab initio electronic-structure calculation utilizing real-space double-grid with a high density of grid points in the vicinity of nuclei. This technique promises to greatly reduce the overhead for performing ... More
First-principles study on dielectric properties of NaCl crystal and ultrathin NaCl films under finite external electric fieldOct 07 2004We present a first-principles study on the dielectric properties of an NaCl crystal and ultrathin NaCl films under a finite external electric field. Our results show that the high-frequency dielectric constant of the films is not affected by the finite ... More
Geometry and Conductance of Al Wires Suspended between Semi-Infinite Crystalline ElectrodesJul 28 2003We present a first-principles study of a coherent relationship between the optimized geometry and conductance of a three-aluminum-atom wire during its elongation process. Our simulation employs the most definite model including semi-infinite crystalline ... More
Broken spacetime symmetries and elastic variablesNov 29 2013Jul 04 2014We discuss spontaneous breaking of continuum symmetries, whose generators do explicitly depend on the spacetime coordinates. We clarify the relation between broken symmetries and elastic variables at both zero and finite temperatures, and/or finite densities, ... More
Collision dynamics of Skyrmions in a two-component Bose-Einstein condensateJan 08 2016The dynamics of Skyrmions in a two-component Bose-Einstein condensate are numerically investigated in the mean-field theory. When two Skyrmions collide with each other, they are first united and then scattered into various states. For head-on collisions, ... More
Complex Langevin simulation of quantum vortices in a Bose-Einstein condensateNov 19 2014Nov 04 2015The ab-initio simulation of quantum vortices in a Bose-Einstein condensate is performed by adopting the complex Langevin techniques. We simulate the nonrelativistic boson field theory at finite chemical potential under rotation. In the superfluid phase, ... More
Accelerated Sparsified SGD with Error FeedbackMay 29 2019We study a stochastic gradient method for synchronous distributed optimization. For reducing communication cost, we are interested in utilizing compression of communicated gradients. Our main focus is a {\it{sparsified}} stochastic gradient method with ... More
Pseudodifferential operators with symbols in the Hörmander class $S^0_{α,α}$ on $α$-modulation spacesJul 31 2017Feb 04 2019In this paper, we study the boundedness of pseudodifferential operators with symbols in the H\"ormander class $S^0_{\rho,\rho}$ on $\alpha$-modulation spaces $M_{p,q}^{s,\alpha}$, and consider the relation between $\alpha$ and $\rho$. In particular, we ... More
Schwinger Mechanism with Stochastic QuantizationMar 17 2014Jun 23 2014We prescribe a formulation of the particle production with real-time Stochastic Quantization. To construct the retarded and the time-ordered propagators we decompose the stochastic variables into positive- and negative-energy parts. In this way we demonstrate ... More
First-Principles Study on Peierls Instability in Infinite Single-Row Al WiresDec 26 2002We present the relation between the atomic and spin-electronic structures of infinite single-row atomic wires made of Al atoms during their elongation using first-principles molecular-dynamics simulations. Our study reveals that the Peierls transition ... More
Instability of Non-vortex State toward a Quantized Vortex in Bose-Einstein Condensate under External RotationFeb 27 1999The instability condition of the non-vortex state toward vortex formation is exa mined within the Bogoliubov theory when a Bose-Einstein condensate is under exte rnally forced rotation. The obtained critical angular velocity combined with the previous ... More
Vortex stabilization in Bose-Einstein condensate of alkali atom gasJul 17 1998Jul 19 1998A quantized vortex in the Bose-Einstein condensation (BEC), which is known to be unstable intrinsically, is demonstrated theoretically to be stabilized by the finite temperature effect. The mean-field calculation of Popov approximation within the Bogoliubov ... More
Bose-Einstein Condensation in a Confined Geometry with and without a VortexAug 27 1997Jul 19 1998Various widely-used mean-field type theories for a dilute Bose gas are critically examined in the light of the recent discovery of Bose-Einstein condensation of atomic gases in a confined geometry. By numerically solving the mean-field equations within ... More
Quadrupole and monopole transition properties of $0^+_2$ in Gd isotopesJan 21 2016Feb 23 2016The longstanding problem of characterization of the $0^+_2$ states in Gd isotopes is revisited by adopting the Nilsson$+$BCS mean field and the random-phase approximation. The interband electric quadrupole transition strengths varying almost two orders ... More
Real-space method for first-principles electron-transport calculations: self-energy terms of electrodes for large systemsNov 05 2015We present a fast and stable numerical technique to obtain the self-energy terms of electrodes for first-principles electron-transport calculations. Although first-principles calculations based on the real-space finite-difference method are advantageous ... More
Molecular Line Observations of a Carbon-Chain-Rich Core L492Apr 04 2006We report on molecular abundances and distributions in a starless dense core L492. We have found that the abundances of carbon-chain molecules such as CCS, C$_{3}$S, HC$_{3}$N, HC$_{5}$N, and HC$_{7}$N are comparable to those in chemically young dark ... More
First-principles electronic-structure calculation of dangling bonds at Si/SiO$_2$ and Ge/GeO$_2$ interfacesNov 30 2009Sep 04 2010Evidence of the absence of the clear electron spin-resonance signal from Ge dangling bonds (DBs) at Ge/GeO$_2$ interfaces is explored by means of first-principles electronic-structure calculations. Comparing the electronic structures of the DBs at Si/SiO$_2$ ... More
A remark on the Schrödinger operator on Wiener amalgam spacesNov 17 2017In this paper, we study the boundedness of the Schr\"odinger operator $e^{i \Delta}$ on Wiener amalgam spaces and determine its optimal condition.
Compressive Change Retrieval for Moving Object DetectionAug 06 2016Change detection, or anomaly detection, from street-view images acquired by an autonomous robot at multiple different times, is a major problem in robotic mapping and autonomous driving. Formulation as an image comparison task, which operates on a given ... More
Lagrange optimality system for a class of nonsmooth convex optimizationFeb 22 2015In this paper, we revisit the augmented Lagrangian method for a class of nonsmooth convex optimization. We present the Lagrange optimality system of the augmented Lagrangian associated with the problems, and establish its connections with the standard ... More
Gravitational wave asteroseismology with protoneutron starsAug 03 2016We examine the time evolution of the frequencies of the gravitational wave after the bounce within the framework of relativistic linear perturbation theory using the results of one dimensional numerical simulations of core-collapse supernovae. Protoneutron ... More
Construction of perfect crystals conjecturally corresponding to Kirillov-Reshetikhin modules over twisted quantum affine algebrasMar 15 2005Assuming the existence of the perfect crystal bases of Kirillov-Reshetikhin modules over simply-laced quantum affine algebras, we construct certain perfect crystals for twisted quantum affine algebras, and also provide compelling evidence that the constructed ... More
Growth of superconducting MgB2 thin filmsMar 08 2002Mar 18 2002This is the first review on superconducting MgB2 thin films as far as we know.
Effect of Quadratic Zeeman Energy on the Vortex of Spinor Bose-Einstein CondensatesJul 25 2006The spinor Bose-Einstein condensate of atomic gases has been experimentally realized by a number of groups. Further, theoretical proposals of the possible vortex states have been sugessted. This paper studies the effects of the quadratic Zeeman energy ... More
Quantum Monte Carlo simulation of a two-dimensional Majorana lattice modelApr 29 2017Jul 18 2017We study interacting Majorana fermions in two dimensions as a low-energy effective model of a vortex lattice in two-dimensional time-reversal-invariant topological superconductors. For that purpose, we implement ab-initio quantum Monte Carlo simulation ... More
Inhomogeneous Polyakov loop induced by inhomogeneous chiral condensatesAug 08 2014We study the spatial inhomogeneity of the Polyakov loop induced by inhomogeneous chiral condensates. We formulate an effective model of gluons on the background fields of chiral condensates, and perform its lattice simulation. On the background of inhomogeneous ... More
String confinement in 2-form lattice gauge theoryMay 11 2019We study the confinement between vortex strings in the dual lattice gauge theory of the abelian Higgs model. The dual lattice gauge theory is described by a 2-form gauge field. We calculate the string-antistring potential from the surface operator of ... More
Stochastic dual averaging methods using variance reduction techniques for regularized empirical risk minimization problemsMar 08 2016We consider a composite convex minimization problem associated with regularized empirical risk minimization, which often arises in machine learning. We propose two new stochastic gradient methods that are based on stochastic dual averaging method with ... More
Doubly Accelerated Stochastic Variance Reduced Dual Averaging Method for Regularized Empirical Risk MinimizationMar 01 2017Sep 19 2017In this paper, we develop a new accelerated stochastic gradient method for efficiently solving the convex regularized empirical risk minimization problem in mini-batch settings. The use of mini-batches is becoming a golden standard in the machine learning ... More
Semiparametric Penalized Spline RegressionFeb 16 2012In this paper, we propose a new semiparametric regression estimator by using a hybrid technique of a parametric approach and a nonparametric penalized spline method. The overall shape of the true regression function is captured by the parametric part, ... More
Demazure submodules of level-zero extremal weight modules and specializations of Macdonald polynomialsApr 09 2014Jan 09 2016In this paper, we give a characterization of the crystal bases $\mathcal{B}_{x}^{+}(\lambda)$, $x \in W_{\mathrm{af}}$, of Demazure submodules $V_{x}^{+}(\lambda)$, $x \in W_{\mathrm{af}}$, of a level-zero extremal weight module $V(\lambda)$ over a quantum ... More
Nonsmooth method for constrained optimizationOct 04 2012We propose an implicit iterative algorithm for an exact penalty method arising from inequality constrained optimization problems. A rapidly convergent fixed point method is developed for a regularized penalty functional. The applicability and feasibility ... More
Chiral magnetic effect by synthetic gauge fieldsJun 11 2016We study the dynamical generation of the chiral chemical potential in a Weyl metal constructed from a three-dimensional optical lattice and subject to synthetic gauge fields. By numerically solving the Boltzmann equation with the Berry curvature in the ... More
First-principles study on atomic configuration of electron-beam irradiated C$_{60}$ clustersMay 16 2011A theoretical study proposes the atomic configuration of electron-beam irradiated C$_{60}$ thin films. We examined the electronic structure and electron-transport properties of the C$_{60}$ clusters using density-functional calculations and found that ... More
Spatial Point Analysis of Quantum Dot Nucleation Sites on InAs Wetting LayerJul 24 2010We perform spatial point analysis of InAs quantum dot nucleation sites and surface reconstruction domain pattern on an InAs wetting layer, giving insights for quantum dot nucleation mechanism. An InAs wetting layer grown to 1.5 monolayers in thickness ... More
First-Principles Study on Electron-Conduction Properties of Helical Gold NanowiresSep 28 2004Multishell helical gold nanowires (HGNs) suspended between semi-infinite electrodes are found to exhibit peculiar electron-conduction properties by first-principles calculations based on the density functional theory. Our results that the numbers of conduction ... More
Direct Minimization Generating Electronic States with Proper Occupation NumbersOct 04 2000We carry out the direct minimization of the energy functional proposed by Mauri, Galli and Car to derive the correct self-consistent ground state with fractional occupation numbers for a system degenerating at the Fermi level. As a consequence, this approach ... More
Dispersion relations of Nambu-Goldstone modes at finite temperature and densityJun 24 2014Mar 31 2015We discuss the dispersion relations of Nambu-Goldstone (NG) modes associated with spontaneous breaking of internal symmetries at finite temperature and/or density. We show that the dispersion relations of type-A (I) and type-B (II) NG modes are linear ... More
Dynamics of a vortex dipole across a magnetic phase boundary in a spinor Bose-Einstein condensateOct 03 2014Dynamics of a vortex dipole in a spin-1 Bose-Einstein condensate in which magnetic phases are spatially distributed is investigated. When a vortex dipole travels from the ferromagnetic phase to the polar phase, or vice versa, it penetrates the phase boundary ... More
Lattice simulation with the Majorana positivityJul 18 2017While the sign problem of the Dirac fermion is conditioned by the semi-positivity of a determinant, that of the Majorana fermion is conditioned by the semi-positivity of a Pfaffian. We introduce one sufficient condition for the semi-positivity of a Pfaffian. ... More
Complex Langevin simulation in condensed matter physicsAug 03 2015The complex Langevin method is one hopeful candidate to tackle the sign problem. This method is applicable not only to QCD but also to nonrelativistic field theory, such as condensed matter physics. We present the simulation results of a rotating Bose ... More
CIP methods for hyperbolic system with variable and discontinuous coefficientJun 09 2011We propose a multi-moment method for one-dimensional hyperbolic equations with smooth coefficient and piecewise constant coefficient. The method is entirely based on the backward characteristic method and uses the solution and its derivative as unknowns ... More
First-Principles Study on Electron-Conduction Properties of C$_{60}$ ChainsJun 21 2006The electron-conduction properties of fullerene chains are examined by first-principles calculations based on the density functional theory. The conductivity of the C$_{60}$ dimer is low owing to the constraint of the junction of the molecules on electron ... More
First-principles study on field evaporation for silicon atom on Si(001) surfaceJul 28 2003The simulations of field-evaporation processes for silicon atoms on various Si(001) surfaces are implemented using the first-principles calculations based on the real-space finite-difference method. We find that the atoms which locate on atomically flat ... More
Classification of sign-problem-free relativistic fermions on the basis of the Majorana positivityJan 25 2017Apr 24 2017We classify the sign-problem-free relativistic fermion actions on the basis of the Majorana representation. In the Majorana representation, the sign-problem-free condition is given by the semi-positivity of a Pfaffian. We show that the known sign-problem-free ... More
A multi-moment scheme for the two dimensional Maxwell's equationsOct 24 2011We develop a numerical scheme for solving time-domain Maxwell's equation. The method is motivated by CIP method which uses function values and its derivatives as unknown variables. The proposed scheme is developed by using the Poisson formula for the ... More
Triharmonic Riemannian submersions from 3-dimensional manifolds of constant curvatureAug 22 2016Sep 09 2016For biharmonic maps, there is a famous conjecture named Chen's conjecture. In later paper, Wang and Ou gave an affirmative partial answer to submersion version of Chen's conjecture. In this paper, we give an affirmative partial answer to submersion version ... More
Sample Efficient Stochastic Gradient Iterative Hard Thresholding Method for Stochastic Sparse Linear Regression with Limited Attribute ObservationSep 05 2018Dec 01 2018We develop new stochastic gradient methods for efficiently solving sparse linear regression in a partial attribute observation setting, where learners are only allowed to observe a fixed number of actively chosen attributes per example at training and ... More
Extraction of Neutrino Flux from the Inclusive Muon Cross SectionJan 23 2015We have studied a method to extract neutrino flux from the data of neutrino-nucleus reaction by using maximum entropy method. We demonstrate a promising example to extract neutrino flux from the inclusive cross section of muon production without selecting ... More
On a Certain Subalgebra of $U_q(\widehat{\mathfrak{sl}}_2)$ Related to the Degenerate $q$-Onsager AlgebraMay 14 2012Jan 19 2015In [Kyushu J. Math. 64 (2010), 81-144, arXiv:0904.2889], it is discussed that a certain subalgebra of the quantum affine algebra $U_q(\widehat{\mathfrak{sl}}_2)$ controls the second kind TD-algebra of type I (the degenerate $q$-Onsager algebra). The subalgebra, ... More