Results for "Kentaro Wakui"

total 725took 0.10s
Braided Morita equivalence for finite-dimensional semisimple and cosemisimple Hopf algebrasJun 08 2018Braided Morita invariants of finite-dimensional semisimple and cosemisimple Hopf algebras with braidings are constructed by refining the polynomial invariants introduced by the author. The invariants are computed for the duals of Suzuki's braided Hopf ... More
Generation of vacuum ultraviolet radiation by intracavity high-harmonic generation toward state detection of single trapped ionsJun 21 2014Aug 22 2014VUV radiation around 159 nm is obtained toward direct excitation of a single trapped $^{115}$In$^{+}$ ion. An efficient fluoride-based VUV output-coupler is employed for intracavity high-harmonic generation of a Ti:S oscillator. Using this coupler, where ... More
Computations of Turaev-Viro-Ocneanu invariants of 3-manifolds from subfactorsAug 30 2002In this paper, we establish a rigorous correspondence between the two tube algebras, that one comes from the Turaev-Viro-Ocneanu TQFT introduced by Ocneanu and another comes from the sector theory introduced by Izumi, and construct a canonical isomorphism ... More
Experimental demonstration of entanglement assisted coding using a two-mode squeezed vacuum stateFeb 05 2004Oct 29 2004We have experimentally realized the scheme initially proposed as quantum dense coding with continuous variables [Ban, J. Opt. B \textbf{1}, L9 (1999), and Braunstein and Kimble, \pra\textbf{61}, 042302 (2000)]. In our experiment, a pair of EPR (Einstein-Podolski-Rosen) ... More
Effective squeezing enhancement via measurement-induced non-Gaussian operation and its application to dense coding schemeMar 04 2005May 18 2005We study the measurement-induced non-Gaussian operation on the single- and two-mode \textit{Gaussian} squeezed vacuum states with beam splitters and on-off type photon detectors, with which \textit{mixed non-Gaussian} states are generally obtained in ... More
(2+1)-dimensional topological quantum field theory with a Verlinde basis and Turaev-Viro-Ocneanu invariants of 3-manifoldsOct 23 2002Mar 21 2003In this article, we discuss a (2+1)-dimensional topological quantum field theory, for short TQFT, with a Verlinde basis. As a conclusion of this general theory, we have a Dehn surgery formula. We show that Turaev-Viro-Ocneanu TQFT has a Verlinde basis. ... More
Widely tunable single photon source with high purity at telecom wavelengthMar 25 2013We theoretically and experimentally investigate the spectral tunability and purity of photon pairs generated from spontaneous parametric down conversion in periodically poled $\mathrm{KTiOPO_4}$ crystal with group-velocity matching condition. The numerical ... More
Experimental verification of a fully inseparable tripartite continuous-variable stateApr 08 2003A continuous-variable tripartite entangled state is experimentally generated by combining three independent squeezed vacuum states and the variances of its relative positions and total momentum are measured. We show that the measured values violate the ... More
Optical continuous-variable qubitFeb 17 2010In a new branch of quantum computing, information is encoded into coherent states, the primary carriers of optical communication. To exploit it, quantum bits of these coherent states are needed, but it is notoriously hard to make superpositions of such ... More
Photon subtraction from traveling fields - recent experimental demonstrationsApr 21 2011We review our most recent results on application of the photon subtraction technique for optical quantum information processing primitives, in particular entanglement distillation and generation of squeezed qubit states. As an introduction we provide ... More
Projective measurement onto arbitrary superposition of coherent state basesFeb 21 2017Feb 15 2018One of the peculiar features in quantum mechanics is that a superposition of macroscopically distinct states can exits. In optical system, this is highlighted by a superposition of coherent states (SCS), i.e. a superposition of classical states. Recently ... More
Optical phase estimation via coherent state and displaced photon countingApr 15 2016Jun 21 2016We consider the phase sensing via weak optical coherent state at quantum limit precision. A new detection scheme for the phase estimation is proposed which is inspired by the suboptimal quantum measurement in coherent optical communication. We theoretically ... More
Generation of large-amplitude coherent-state superposition via ancilla-assisted photon-subtractionJun 18 2008Dec 05 2008We propose and demonstrate a novel method to generate a large-amplitude coherent-state superposition (CSS) via ancilla-assisted photon-subtraction. The ancillary mode induces quantum interference of indistinguishable processes, widening the controllability ... More
Optimal conditions for Bell test using spontaneous parametric down-conversion sourcesAug 25 2018We theoretically and experimentally investigate the optimal conditions for the Bell experiment using spontaneous parametric down conversion (SPDC) sources. In theory, we show that relatively large average photon number (typically $\sim$0.5) is desirable ... More
(2+1)-dimensional topological quantum field theory from subfactors and Dehn surgery formula for 3-manifold invariantsAug 30 2002In this paper, we establish the general theory of (2+1)-dimensional topological quantum field theory (in short, TQFT) with a Verlinde basis. It is a consequence that we have a Dehn surgery formula for 3-manifold invariants for this kind of TQFT's. We ... More
Macroscopic Reality in Quantum Mechanics; Origin and DissipationMar 01 2007We study the connection between dissipation and reality in macroscopic quantum systems. We present the following scenario; if we consider the dynamics of a `partial' wave function, the dissipation is represented as a nonlocal term and it causes destructive ... More
Analysis of Quantum Entanglement in Quantum Programs using Stabilizer FormalismNov 05 2015Quantum entanglement plays an important role in quantum computation and communication. It is necessary for many protocols and computations, but causes unexpected disturbance of computational states. Hence, static analysis of quantum entanglement in quantum ... More
Annealing Approach to Quantum TomographyApr 04 2019Annealing approach to quantum tomography is theoretically proposed. First, based on the maximum entropy principle, we introduce classical parameters to combine "quantum models (or quantum states)" given a prior for potentially representing the unknown ... More
Criteria for singularities of smooth maps from the plane into the plane and its applicationsMay 15 2009Feb 12 2010We shall give useful criteria of lips, beaks and swallowtail singularities of smooth map from the plane into the plane. As an application of criteria, we will discuss the singularities of Cauchy problem of single conservation law.
Normal form of swallowtail and its applicationsMar 27 2017We construct a form of swallowtail singularity in R^3 which uses coordinate transformation on the source and isometry on the target. As an application, we classify configurations of asymptotic curves and characteristic curves near swallowtail.
Derived categories of small toric Calabi-Yau 3-folds and counting invariantsSep 17 2008Feb 07 2011We first construct a derived equivalence between a small crepant resolution of an affine toric Calabi-Yau 3-fold and a certain quiver with a superpotential. Under this derived equivalence we establish a wall-crossing formula for the generating function ... More
Refined open non-commutative Donaldson-Thomas invariants for small crepant resolutionsJul 22 2009Oct 02 2010The aim of this paper is to study an analog of non-commutative Donaldson-Thomas theory corresponding to the refined topological vertex for small crepant resolutions of toric Calabi-Yau 3-folds. We define the invariants using dimer models and provide "wall-crossing" ... More
Coupling Lemma and Its Application to The Security Analysis of Quantum Key DistributionMay 23 2015It is known that the coupling lemma provides a useful tool in the study of probability theory and its related areas. It describes the relation between the variational distance of two probability distributions and the probability that outcomes from the ... More
Blocks of category $\mathcal{O}$ for rational Cherednik algebras and of cyclotomic Hecke algebras of type G(r,p,n)Feb 08 2010We classify blocks of category $\mathcal{O}$ for rational Cherednik algebras and of cyclotomic Hecke algebras of type G(r,p,n) by using the "residue equivalence" for multi-partitions.
Presenting cyclotomic q-Schur algebrasAug 23 2009We give a presentation of cyclotomic q-Schur algebras by generators and defining relations. As an application, we give an algorithm for computing decomposition numbers of cyclotomic q-Schur algebras.
A cellular algebra with certain idempotent decompositionMay 08 2008For a cellular algebra $\A$ with a cellular basis $\ZC$, we consider a decomposition of the unit element $1_\A$ into orthogonal idempotents (not necessary primitive) satisfying some conditions. By using this decomposition, the cellular basis $\ZC$ can ... More
On decomposition numbers with Jantzen filtration of cyclotomic $q$-Schur algebrasJul 12 2007Let $\Sc(\vL)$ be the cyclotomic $q$-Schur algebra associated to the Ariki-Koike algebra $\He_{n,r}$, introduced by Dipper-James-Mathas. In this paper, we consider $v$-decomposition numbers of $\Sc(\vL)$, namely decomposition numbers with respect to the ... More
Charged rotating black holes at large DMay 28 2016We study odd dimensional charged equally rotating black holes in the Einstein-Maxwell theory with/without a cosmological constant by using the large D expansion method, where D is a spacetime dimension. Solving the Einstein-Maxwell equations in the 1/D ... More
Instability of de Sitter Reissner-Nordstrom black hole in the 1/D expansionNov 19 2015May 17 2016We study large D effective theory for D dimensional charged (Anti) de Sitter black holes. Then we show that de Sitter Reissner-Nordstrom black hole becomes unstable against gravitational perturbations at larger charge than certain critical value in higher ... More
Iwasawa theory of de Rham (φ,Γ)-modules over the Robba ringsJan 31 2012Dec 02 2012The aim of this article is to study Bloch-Kato's exponential map and Perrin-Riou's "big" exponential map purely in terms of (\phi,\Gamma)-modules over the Robba ring. We first generalize the definition of Bloch-Kato's exponential map for all the (\phi,\Gamma)-modules ... More
Mixture of Quantum States: Thermal and Interaction Inducing DecoherenceMay 09 2011In this study, we show that the interaction energy plays an important role on the quantum decoherence: If we pay attention to the oscillation phase factor, $e^{-iE_{int}t/\hbar},$ we see that the time average of the macro-system's density matrix becomes ... More
DSL-based Design Space Exploration for Temporal and Spatial Parallelism of Custom Stream ComputingAug 27 2015Stream computation is one of the approaches suitable for FPGA-based custom computing due to its high throughput capability brought by pipelining with regular memory access. To increase performance of iterative stream computation, we can exploit both temporal ... More
Pointer States and Decoherence in Quantum Unitarity: Energy Conservation for Weak Interaction ModelOct 19 2016The purpose of the present paper is to derive the pointer states of a macro-object using a simple perturbation method. We study the model Hamiltonian involving the weak interaction between the center of mass and its environment. The main conclusion is ... More
On continuous extension of grafting mapsNov 06 2004The definition of the grafting operation for quasifuchsian groups is extended by Bromberg to all $b$-groups. Although the grafting maps are not necessarily continuous at boundary groups, in this paper, we show that the grafting maps take every "standard" ... More
The accurate optimal-success/error-rate calculations applied to the realizations of the reliable and short-period integer ambiguity resolution in carrier-phase GPS/GNSS positioningAug 02 2005Nov 08 2005The maximum-marginal-a-posteriori success rate of statistical decision under multivariate Gaussian error distribution on an integer lattice is almost rigorously calculated by using union-bound approximation and Monte Carlo integration. These calculations ... More
Strong consistency of the maximum likelihood estimator for finite mixtures of location-scale distributions when penalty is imposed on the ratios of the scale parametersOct 11 2007Feb 08 2008In finite mixtures of location-scale distributions, if there is no constraint or penalty on the parameters, then the maximum likelihood estimator does not exist because the likelihood is unbounded. To avoid this problem, we consider a penalized likelihood, ... More
Strong consistency of MLE for finite mixtures of location-scale distributions when the ratios of the scale parameters are exponentially smallSep 25 2006Oct 12 2007In finite mixtures of location-scale distributions, if there is no constraint on the parameters then the maximum likelihood estimate does not exist. But when the ratios of the scale parameters are restricted appropriately, the maximum likelihood estimate ... More
Criteria for Morin singularities for maps into lower dimensions, and applicationsOct 19 2015Oct 21 2015We give criteria for Morin singularities for germs of maps into lower dimensions. As an application, we study the bifurcation of Lefschetz singularities.
Criteria for Morin singularities into higher dimensionsDec 12 2014We give criteria for Morin singularities into higher dimensions. As an application, we study the number of A-isotopy classes of Morin singularities.
On higher rank Donaldson-Thomas invariantsFeb 18 2010We study higher rank Donaldson-Thomas invariants of a Calabi-Yau 3-fold using Joyce-Song's wall-crossing formula. We construct quivers whose counting invariants coincide with the Donaldson-Thomas invariants. As a corollary, we prove the integrality and ... More
Another proof to Kotschick-Morita's Theorem of Kontsevich homomorphismJul 03 2014In \cite{KOT:MORITA}, Kotschick and Morita showed that the Gel'fand-Kalinin-Fuks class in $\ds \HGF{7}{2}{}{8}$ is decomposed as a product $\eta\wedge \omega $ of some leaf cohomology class $\eta$ and a transverse symplectic class $\omega$. In other words, ... More
Deformations of trianguline B-pairsFeb 01 2010Feb 10 2010The aim of this article is to study deformation theory of trianguline B-pairs for any p-adic field. For benign B-pairs, a special good class of trianguline B-pairs, we prove a main theorem concerning tangent spaces of these deformation spaces. These are ... More
The representation type of Ariki-Koike algebras and cyclotomic q-Schur algebrasSep 17 2008Feb 09 2010We give a necessary and sufficient condition on parameters for Ariki-Koike algebras (resp. cyclotomic q-Schur algebras) to be of finite representation type.
Convergence and divergence of Kleinian punctured torus groupsJan 12 2007Jul 01 2011In this paper we give a necessary and sufficient condition in which a sequence of Kleinian punctured torus groups converges. This result tells us that every exotically convergent sequence of Kleinian punctured torus groups is obtained by the method due ... More
Quiver varieties and Frenkel-Kac constructionMar 04 2007An affine Lie algebra acts on cohomology groups of quiver varieties of affine type. A Heisenberg algebra acts on cohomology groups of Hilbert schemes of points on a minimal resolution of a Kleinian singularity. We show that in the case of type $A$ the ... More
Linear slices close to a Maskit sliceMar 29 2013We consider linear slices of the space of Kleinian once-punctured torus groups; a linear slice is obtained by fixing the value of the trace of one of the generators. The linear slice for trace 2 is called the Maskit slice. We will show that if traces ... More
Semiclassical study of shape resonances in the Stark effectJan 24 2019Semiclassical behavior of Stark resonances is studied. The complex distortion outside a cone is introduced and resonances are defined in any energy region for the Stark Hamiltonians with non-globally analytic potentials. The non-trapping resolvent estimate ... More
Black rings at large DOct 08 2015Mar 01 2016We study the effective theory of slowly rotating black holes at the infinite limit of the spacetime dimension D. This large D effective theory is obtained by integrating the Einstein equation with respect to the radial direction. The effective theory ... More
Pisot conjecture and Rauzy fractalsOct 11 2016Oct 13 2016We provide a proof of Pisot conjecture, a classification problem in Ergodic Theory on recurrent sequences generated by irreducible Pisot substitutions.
Local epsilon-isomorphisms for rank two p-adic representations of Gal(overline{Q}_p/Q_p) and a functional equation of Kato's Euler systemFeb 17 2015Feb 16 2016In this article, we prove (many parts of) the rank two case of the Kato's local epsilon-conjecture using the Colmez's p-adic local Langlands correspondence for GL_2(Q_p). We show that a Colmez's pairing defined in his study of locally algebraic vectors ... More
Quantum Decoherence and Pointer Basis: Dynamics in State VectorsJul 01 2009Aug 12 2009It is well-known that the pointer basis of a quantum system satisfies the condition to diagonalize the interaction Hamiltonian between the subsystems. We show that this condition can be translated into the form $\delta\Lambda=0,$ where $\Lambda$, so-called ... More
Classicality in Quantum Mechanics: model for pointer states and decoherenceMar 31 2016We have studied the emergence of classical states in the perturbative interaction model. The states which interact with many other degrees of freedom, such as the center of mass of a macro-object, play important role. Although the random phase mechanism ... More
Effects of Boundary Conditions on Magnetic FrictionDec 08 2018We consider magnetic friction between two square lattices of the ferromagnetic Ising model of finite thickness. We analyze the dependence on the boundary conditions and the sample thickness. Monte Carlo results indicate that the setup enables us to control ... More
Remarks on semiclassical wavefront setMar 08 2018Apr 05 2018The essential support of the symbol of a semiclassical pseudodifferentail operator is characterized by semiclassical wavefront sets of distributions. The proof employs a coherent state whose center in the phase space is dependent on Plank's constant.
K-theory of quiver varieties, q-Fock space and nonsymmetric Macdonald polynomialsSep 12 2007We have two constructions of the level-$(0,1)$ irreducible representation of the quantum toroidal algebra of type $A$. One is due to Nakajima and Varagnolo-Vasserot. They constructed the representation on the direct sum of the equivariant K-groups of ... More
Braid zeta function and some formulae for the torus typeNov 25 2016There is a well-known zeta function of the $\mathbb{Z}$-dynamical system generated by an element of the symmetric group. By considering this zeta function as a model, we can construct a new zeta function of an element of the braid group.In this paper,we ... More
Non-commutative Donaldson-Thomas theory and vertex operatorsOct 29 2009Nov 23 2010In arXiv:0907.3784, we introduced a variant of non-commutative Donaldson-Thomas theory in a combinatorial way, which is related with topological vertex by a wall-crossing phenomenon. In this paper, we (1) provide an alternative definition in a geometric ... More
Wall-crossing of the motivic Donaldson-Thomas invariantsMar 15 2011We study motivic Donaldson-Thomas invariants in the sense of Behrend-Bryan-Szendroi. A wall-crossing formula under a mutation is proved for a certain class of quivers with potentials.
Criteria for cuspidal S_k singularities and their applicationsMay 14 2009May 03 2010We give useful criteria for S_1 singularities in the Mond classification table, and cuspidal S_k singularities. As applications, we give a simple proof of a result given by Mond and a characterization of cuspidal S_k singularities for the composition ... More
Induction and Restriction Functors for Cyclotomic q-Schur AlgebrasDec 28 2011We define the induction and restriction functors for cyclotomic q-Schur algebras, and study some properties of them. As an application, we categorify a higher level Fock space by using the module categories of cyclotomic q-Schur algebras.
Uniform Proofs of Normalisation and Approximation for Intersection TypesMar 17 2015We present intersection type systems in the style of sequent calculus, modifying the systems that Valentini introduced to prove normalisation properties without using the reducibility method. Our systems are more natural than Valentini's ones and equivalent ... More
Elastic instability of black rings at large DMay 26 2016Using the inverse dimensional expansion method we study the elastic instability of black rings found recently in numerical analysis of fully nonlinear dynamical evolutions. In our analysis we should perform 1/D^1/2 expansions, not usual 1/D expansions, ... More
A generalization of Kato's local epsilon-conjecture for (phi,Gamma)-modules over the Robba ringMay 04 2013Feb 15 2015The aim of this article is to generalize Kato's (commutative) p-adic local epsilon-conjecture [Ka93b] for families of (phi,Gamma)-modules over the Robba ring. In particular, we prove the generalized local epsilon-conjecture for rank one (phi,Gamma)-modules, ... More
Differentiability of quantum moment mapsOct 03 2002We study quantum moment maps of $G$-invariant star products, which are a quantum analogue of the moment map for classical Hamiltonian systems. Introducing an integral representation, we show that any quantum moment map for a $G$-invariant star product ... More
Graphical Classification of Entangled QutritsOct 02 2012A multipartite quantum state is entangled if it is not separable. Quantum entanglement plays a fundamental role in many applications of quantum information theory, such as quantum teleportation. Stochastic local quantum operations and classical communication ... More
A General Derivation of Pointer States: Decoherence and ClassicalityApr 17 2014The purpose of the present study is to derive the pointer states of a macroscopic system interacting with its environment, under the general assumptions, i.e., without assuming any form of the interaction Hamiltonian. The lowest order perturbation leads ... More
Reduction and possible elimination of coating thermal noise using a rigidly controlled cavity with a QND techniqueNov 11 2008Thermal noise of a mirror is one of the most important issues in high precision measurements such as gravitational-wave detection or cold damping experiments. It has been pointed out that thermal noise of a mirror with multi-layer coatings can be reduced ... More
Isotopy of Morin singularitiesOct 13 2015We define an equivalence relation called A-isotopy between finitely determined map-germs, which is a strengthened version of A-equivalence. We consider the number of A-isotopy classes of equidimensional Morin singularities, and some other well-known low-dimensional ... More
Quantum moment maps and invariants for G-invariant star productsMar 20 2002We study a quantum moment map and propose an invariant for $G$-invariant star products on a $G$-transitive symplectic manifold. We start by describing a new method to construct a quantum moment map for $G$-invariant star products of Fedosov type. We use ... More
Criteria for D_4 singularities of wave frontsJun 29 2009Jul 04 2010We give useful and simple criteria for determining D_4 singularities of wave fronts. As an application, we investigate behaviors of singular curvatures of cuspidal edges near D_4^+ singularities.
Quasi-Bell entangled coherent states and its quantum discrimination problem in the presence of thermal noiseAug 07 2015The so-called quasi-Bell entangled coherent states in a thermal environment are studied. In the analysis, we assume thermal noise affects only one of the two modes of each state. First the matrix representation of the density operators of the quasi-Bell ... More
Broad Balmer-line Absorption in SDSS J172341.10+555340.5Mar 24 2010Aug 03 2010I present the discovery of Balmer-line absorption from H alpha to H9 in iron low-ionizaton broad absorption line (FeLoBAL) quasar, SDSS~J172341.10+555340.5 by near-infrared spectroscopy with the Cooled Infrared Spectrograph and Camera for OHS (CISCO) ... More
Nonclasscial interference between independent intrinsically pure single photons at telecom wavelengthMar 12 2013Jul 24 2013We demonstrate a Hong-Ou-Mandel interference between two independent, intrinsically pure, heralded single photons from spontaneous parametric down conversion (SPDC) at telecom wavelength. A visibility of $85.5\pm8.3%$ was achieved without using any bandpass ... More
On Weyl modules of cyclotomic $q$-Schur algebrasJan 04 2011We study on Weyl modules of cyclotomic $q$-Schur algebras. In particular, we give the character formula of the Weyl modules by using the Kostka numbers and some numbers which are computed by a generalization of Littlewood-Richardson rule. We also study ... More
Pisot conjecture and Rauzy fractalsOct 11 2016Oct 14 2016We provide a proof of Pisot conjecture, a classification problem in Ergodic Theory on recurrent sequences generated by irreducible Pisot substitutions.
Zariski density of crystalline representations for any p-adic fieldApr 10 2011Nov 25 2013The aim of this article is to prove Zariski density of crystalline representations in the rigid analytic space associated to the universal deformation ring of a d-dimensional mod p representation of Gal(\bar{K}/K) for any d and for any p-adic field K. ... More
Publicly Verifiable Blind Quantum ComputationApr 01 2016Blind quantum computation protocols allow a user with limited quantum technology to delegate an intractable computation to a quantum server while keeping the computation perfectly secret. Whereas in some protocols a user can verify that calculated outcomes ... More
The relative Gel'fand-Kalinin-Fuks cohomology groups of the formal Hamiltonian vector fields on 6-dimensional planeFeb 27 2014Using Crystal basis theory, we study the relative Gel'fand-Kalinin-Fuks cohomology groups of the formal Hamiltonian vector fields on 6-dimensional plane with weight =2,4,6.
On pairs of geometric foliations on a cuspidal edgeMar 27 2017We study the topological configurations of the lines of principal curvature, the asymptotic and characteristic curves on a cuspidal edge, in the domain of a parametrization of this surface as well as on the surface itself. Such configurations are determined ... More
Exotic projective structures and quasifuchsian spaces IIMar 03 2006Let $P(S)$ be the space of projective structures on a closed surface $S$ of genus $g >1$ and let $Q(S)$ be the subset of $P(S)$ of projective structures with quasifuchsian holonomy. It is known that $Q(S)$ consists of infinitely many connected components. ... More
Deformations of trianguline B-pairs and Zariski density of two dimensional crystalline representationsJun 25 2010Nov 25 2013The aim of this article is to study deformation theory of trianguline B-pairs for any p-adic field. For benign B-pairs, a special good class of trianguline B-pairs, we prove a main theorem concerning tangent spaces of these deformation spaces. These are ... More
Classification of two dimensional split trianguline representations of $p$-adic fieldsJan 08 2008Nov 01 2008The aim of this paper is to classify two dimensional split trianguline representations of $p$-adic fields. This is a generalization of a result of Colmez who classified two dimensional split trianguline representations of $\mathrm{Gal}(\bar{\mathbb{Q}}_p/\mathbb{Q}_p)$ ... More
Donaldson-Thomas theory and cluster algebrasFeb 26 2010May 17 2011We provide a transformation formula of non-commutative Donaldson-Thomas invariants under a composition of mutations. Consequently, we get a description of a composition of cluster transformations in terms of quiver Grassmannians. As an application, we ... More
Minimizing CM degree and slope stability of projective varietiesNov 29 2018Feb 09 2019We discuss a minimization problem of the degree of the CM line bundle among all possible fillings of a polarized family with fixed general fibers. We show that such minimization implies the slope semistability of the fiber if the central fiber is smooth. ... More
New realization of cyclotomic $q$-Schur algebras IApr 15 2015We introduce a Lie algebra $\mathfrak{g}_{\mathbf{Q}}(\mathbf{m})$ and an associative algebra $\mathcal{U}_{q,\mathbf{Q}}(\mathbf{m})$ associated with the Cartan data of $\mathfrak{gl}_m$ which is separated into $r$ parts with respect to $\mathbf{m}=(m_1, ... More
Ultrabroadband direct detection of nonclassical photon statistics at telecom wavelengthAug 08 2013Broadband light sources play essential roles in diverse fields, such as high-capacity optical communications, optical coherence tomography, optical spectroscopy, and spectrograph calibration. Though an ultrabroadband nonclassical state from standard spontaneous ... More
Efficient detection of a highly bright photon source using superconducting nanowire single photon detectorsSep 05 2013May 06 2014We investigate the detection of an ultra-bright single-photon source using highly efficient superconducting nanowire single-photon detectors (SNSPDs) at telecom wavelengths. Both the single-photon source and the detectors are characterized in detail. ... More
Pulsed Sagnac polarization-entangled photon source with a PPKTP crystal at telecom wavelengthNov 14 2013May 06 2014We demonstrate pulsed polarization-entangled photons generated from a periodically poled $\mathrm{KTiOPO_4}$ (PPKTP) crystal in a Sagnac interferometer configuration at telecom wavelength. Since the group-velocity-matching (GVM) condition is satisfied, ... More
Polynomial invariants for a semisimple and cosemisimple Hopf algebra of finite dimensionJul 01 2009We introduce new polynomial invariants of a finite-dimensional semisimple and cosemisimple Hopf algebra A over a field by using the braiding structures of A. We investigate basic properties of the polynomial invariants including stability under extension ... More
Heralded amplification of nonlocality via entanglement swapping for long-distance device-independent quantum key distributionApr 12 2019To realize the practical implementation of device-independent quantum key distribution~(DIQKD), the main difficulty is that its security relies on the detection-loophole-free violation of the Clauser-Horne-Shimony-Holt~(CHSH) inequality, i.e. the CHSH ... More
Experimental demonstration of quantum teleportation of a squeezed stateNov 10 2003Apr 19 2005Quantum teleportation of a squeezed state is demonstrated experimentally. Due to some inevitable losses in experiments, a squeezed vacuum necessarily becomes a mixed state which is no longer a minimum uncertainty state. We establish an operational method ... More
Association schemoids and their categoriesApr 25 2013Aug 13 2013We propose the notion of association schemoids generalizing that of association schemes from small categorical points of view. In particular, a generalization of the Bose-Mesner algebra of an association scheme appears as a subalgebra in the category ... More
Weyl semimetal phase in solid-solution narrow-gap semiconductorsApr 21 2014We theoretically investigate ferromagnetic ordering in magnetically doped solid-solution narrow-gap semiconductors with the strong spin-orbit interaction such as Cr-doped Bi$_2$(Se$_x$Te$_{1-x}$)$_3$. We compute the spontaneous magnetization of impurities ... More
Aspects of Non-Abelian Gauge Dynamics in Two-Dimensional N=(2,2) TheoriesSep 05 2006Mar 01 2007We study various aspects of N=(2,2) supersymmetric non-Abelian gauge theories in two dimensions, with applications to string vacua. We compute the Witten index of SU(k) SQCD with N>0 flavors with twisted masses; the result is presented as the solution ... More
Light Gauginos and Conformal SequesteringMar 29 2010Apr 02 2010In a wide class of direct and semi-direct gauge mediation models, it has been observed that the gaugino masses vanish at leading order. It implies that there is a hierarchy between the gaugino and sfermion masses, invoking a fine-tuning problem in the ... More
Strong consistency of MLE for finite uniform mixtures when the scale parameters are exponentially smallSep 13 2004We consider maximum likelihood estimation of finite mixture of uniform distributions. We prove that maximum likelihood estimator is strongly consistent, if the scale parameters of the component uniform distributions are restricted from below by exp(-n^d), ... More
Geometric invariants of $5/2$-cuspidal edgesOct 16 2017Feb 16 2019We introduce two invariants called the secondary cuspidal curvature and the bias on $5/2$-cuspidal edges, and investigate their basic properties. While the secondary cuspidal curvature is an analog of the cuspidal curvature of (ordinary) cuspidal edges, ... More
The second Betti number of doubly weighted homology groups of some pre Lie superalgebraFeb 25 2019We already showed that Betti numbers are all zero when w is not equal to h for (w,h)-doubly weighted homology groups of some special pre Lie superalgebra and showed the first Betti number is 0 when w = h. In this note, we show that the second Betti number ... More
An extension of the Maskit slice for 4-dimensional Kleinian groupsJul 17 2007Oct 27 2008Let $\Gamma$ be a 3-dimensional Kleinian punctured torus group with ccidental parabolic transformations. The deformation space of $\Gamma$ in the group of M\"{o}bius transformations on the 2-sphere is well-known as the Maskit slice of punctured torus ... More
Logarithmic good reduction and the indexNov 30 2017Dec 01 2017Let $K$ be the fraction field of a complete discrete valuation ring, with algebraically closed residue field of characteristic $p > 0$. This paper studies the index of a smooth, proper $K$-variety $X$ with logarithmic good reduction. We prove that it ... More