Results for "Ryo Nagai"

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Tree level unitarity and finiteness of electroweak oblique correctionsApr 29 2015We study perturbative unitarity and electroweak oblique corrections in the electroweak symmetry breaking models including an arbitrary number of neutral Higgs bosons. Requiring the perturbative unitarity of the high energy scattering amplitudes of weak ... More
Classification of simple heavy vector triplet modelsJul 13 2016We classify models beyond the standard model with extra spin-1 particles ($V'$) based on the dominant decay mode of $V'$. We find two categories in which $V'$ mainly decay into fermions or bosons. We study simple renormalizable models where the electroweak ... More
Does unitarity imply finiteness of electroweak oblique corrections at one-loop? - constraining extra neutral Higgs bosons -Sep 05 2014Jan 09 2015Introducing arbitrary number of neutral Higgs bosons in the electroweak symmetry breaking sector, we derive a set of conditions among Higgs couplings which need to be satisfied to maintain the unitarity of the high energy scattering amplitudes of weak ... More
Renormalization Effects on Electric Dipole Moments in Electroweakly Interacting Massive Particle ModelsFeb 14 2019We study the renormalization effects on electric dipole moments in the models with new electroweakly interacting massive fermions. The electric dipole moments are generated by the effective operators which arise from integrating out heavy particles at ... More
Effective Theories for Dark Matter Nucleon ScatteringFeb 08 2015May 11 2015We reformulate the calculation of the dark matter-nucleon scattering cross sections based on the method of effective field theories. We assume that the scatterings are induced by the exchange of colored mediators, and construct the effective theories ... More
Heavy Gravitino from Dynamical Generation of Right-Handed Neutrino Mass Scale, and Gravitational WavesMay 11 2018Jul 31 2018The absence of supersymmetric particles at the weak scale is a puzzle if supersymmetry solves the gauge hierarchy problem. We show that, if the right-handed neutrino masses arise from hidden gaugino condensation via GUT-suppressed operators, successful ... More
Symmetric products of a semistable degeneration of surfacesSep 08 2016We explicitly construct a $V$-normal crossing Gorenstein canonical model of the relative symmetric products of a local semistable degeneration of surfaces without a triple point by means of toric geometry. Using this model, we calculate the stringy $E$-polynomial ... More
On monodromies of a degeneration of irreducible symplectic Kähler manifoldsMay 09 2006May 07 2007We study the monodromy operators on the betti cohomologies associated to a good degeneration of irreducible symplectic manifold and we show that the unipotency of the monodromy operator on the middle cohomology is at least the half of the dimension.
Field-angle-dependent low-energy excitations around a vortex in the superconducting topological insulator CuxBi2Se3Apr 28 2014May 13 2014We study the quasiparticle excitations around a single vortex in the superconducting topological insulator Cu$_{x}$Bi$_{2}$Se$_{3}$, focusing on a superconducting state with point nodes. Inspired by the recent Knight shift measurements, we propose two ... More
Unitarity sum rules, three site moose model, and the ATLAS 2 TeV diboson anomaliesJul 05 2015Aug 25 2015We investigate $W'$ interpretations for the ATLAS 2 TeV diboson anomalies. The roles of the unitarity sum rules, which ensure the perturbativity of the longitudinal vector boson scattering amplitudes, are emphasized. We find the unitarity sum rules and ... More
Non-fragile superconductivity with nodes in the superconducting topological insulator CuxBi2Se3: Zeeman orbital field and non-magnetic impuritiesOct 17 2014Jan 26 2015We study the robustness against non-magnetic impurities in the topological superconductor with point nodes, focusing on an effective model of Cu$_{x}$Bi$_{2}$Se$_{3}$. We find that the topological superconductivity with point-nodes is not fragile against ... More
Non-locally-free locus of O'Grady's ten dimensional exampleJul 09 2010We give a completely explicit description of the fibers of the natural birational morphism from O'Grady's ten dimensional singular moduli space of sheaves on a K3 surface to the corresponding Donaldson-Uhlenbeck compactification.
Ultradiscrete Permanent Solution to the Ultradiscrete KP EquationNov 28 2016We propose an ultradiscrete permanent solution to the ultradiscrete KP equation. The ultradiscrete permanent is an ultradiscrete analogue of the usual permanent. The elements on this ultradiscrete permanent solution are required some additional relations ... More
Teleportation stretching for lossy Gaussian channelsMar 16 2016If a quantum channel is commutable with a certain set of operators, a Choi state of the channel becomes a sufficient resource for any entanglement generation achieved by a single use of the channel with the help of local operation and classical communications ... More
Contravariantly finite resolving subcategories over commutative ringsFeb 02 2010Contravariantly finite resolving subcategories of the category of finitely generated modules have been playing an important role in the representation theory of algebras. In this paper we study contravariantly finite resolving subcategories over commutative ... More
Classifying thick subcategories of the stable category of Cohen-Macaulay modulesAug 02 2009Jun 21 2010Various classification theorems of thick subcategories of a triangulated category have been obtained in many areas of mathematics. In this paper, as a higher-dimensional version of the classification theorem of thick subcategories of the stable category ... More
Revisit on How to Derive Asymptotic Profiles to Some Evolution EquationsJun 16 2015We consider the Cauchy problem in ${\bf R}^{n}$ for heat and damped wave equations. We derive asymptotic profiles to those solutions with weighted $L^{1,1}({\bf R}^{n})$ data by presenting a simple method.
Downside risk minimization via a large deviations approachMay 03 2012We consider minimizing the probability of falling below a target growth rate of the wealth process up to a time horizon $T$ in an incomplete market model, and then study the asymptotic behavior of minimizing probability as $T\to\infty$. This problem can ... More
Birational geometry of O'Grady's six dimensional example over the Donaldson-Uhlenbeck compactificationJul 09 2010We determine the birational geometry of O'Grady's six dimensional example over the Donaldson-Uhlenbeck compactification, by looking at the locus of non-locally-free sheaves on the relevant moduli space.
Neural-network Kohn-Sham exchange-correlation potential and its out-of-training transferabilityFeb 08 2018We incorporate in the Kohn-Sham self consistent equation a trained neural-network projection from the charge density distribution to the Hartree-exchange-correlation potential $n \rightarrow V_{\rm Hxc}$ for possible numerical approach to the exact Kohn-Sham ... More
Contour deformation trick in hybrid NLIEFeb 17 2012Jun 15 2012The hybrid NLIE of AdS_5 x S^5 is applied to a wider class of states. We find that the Konishi state of the orbifold AdS_5 x (S^5/Z_S) satisfies A_1 NLIE with the source terms which are derived from contour deformation trick. For general states, we construct ... More
Giant Magnons on CP^3 by Dressing MethodFeb 19 2009May 18 2009We consider classical string spectrum of R x CP^3, and construct a family of solutions with residual SU(2) symmetry by the dressing method on SU(4)/U(3) sigma model. All of them obey the square-root type dispersion relation, as is expected from the su(2|2) ... More
Finiteness of the number of minimal atoms in Grothendieck categoriesMar 07 2015For a Grothendieck category having a noetherian generator, we prove that there exist only finitely many minimal atoms. This is a far-reaching generalization of the well-known fact that every commutative noetherian ring has only finitely many minimal prime ... More
An intrinsic non-triviality of graphsApr 26 2008Feb 01 2009We say that a graph is intrinsically non-trivial if every spatial embedding of the graph contains a non-trivial spatial subgraph. We prove that an intrinsically non-trivial graph is intrinsically linked, namely every spatial embedding of the graph contains ... More
A refinement of the Conway-Gordon theoremsJul 01 2009Aug 12 2009In 1983, Conway-Gordon showed that for every spatial complete graph on 6 vertices, the sum of the linking numbers over all of the constituent 2-component links is congruent to 1 modulo 2, and for every spatial complete graph on 7 vertices, the sum of ... More
Equivalences between weight modules via $\mathcal{N}=2$ coset constructionsMay 08 2016Nov 07 2016In this paper we introduce a variant of weight modules for certain conformal vertex superalgebras as an appropriate framework of the $\mathcal{N}=2$ supersymmetric coset construction. We call them weight-wise admissible modules. Motivated by the work ... More
Hybrid NLIE for the Mirror AdS_5 x S^5Jan 26 2011Oct 07 2011We revisit the derivation of hybrid nonlinear integral equations of the XXX model starting from the linearization of the T-system related to spinon variables. We obtain two sets of equations, corresponding to two linearly independent solutions of A_1 ... More
Separate seesaw and its applications to dark matter and baryogenesisMar 01 2013Jul 02 2013We propose a new seesaw model in an extra-dimensional setup where only right-handed neutrinos are bulk fields. In the model, localizations of an extra-dimensional wave function and brane Majorana mass of the right-handed neutrinos can be different among ... More
When is there a nontrivial extension-closed subcategory?Jan 05 2011Let R be a commutative Noetherian local ring, and denote by mod R the category of finitely generated R-modules. In this paper, we consider when mod R has a nontrivial extension-closed subcategory. We prove that this is the case if there are part of a ... More
Asymptotic profile of solutions for strongly damped Klein-Gordon equationsMay 29 2018We consider the Cauchy problem in the whole space for strongly damped Klein-Gordon equations. We derive asymptotic profles of solutions with weighted initial data by a simple method introduced by R. Ikehata. The obtained results show that the wave effect ... More
Non-exactness of direct products of quasi-coherent sheavesOct 20 2018For a noetherian scheme that has an ample family of invertible sheaves, we prove that direct products in the category of quasi-coherent sheaves are not exact unless the scheme is affine. This result can especially be applied to all quasi-projective schemes ... More
Curvature Perturbations from a Massive Vector CurvatonJul 23 2012Jul 30 2012We study a ghost-free model of massive vector curvaton proposed in the literature, where the quick decrease of the vector background expectation value is avoided by a suitable choice of kinetic and mass functions. The curvaton perturbations of this model ... More
The Yang-Mills gradient flow and lattice effective actionOct 28 2015Jul 28 2016Recently, the Yang-Mills gradient flow is found to be a useful concept not only in lattice simulations but also in continuous field theories. Since its smearing property is similar to the Wilsoninan "block spin transformation", there might be deeper connection ... More
Stabilizer group of generalized determinantJan 25 2017In this paper, we consider linear combination of determinant and permanent, which we call generalized determinant, and determine the stabilizer group of it.
Classifying Serre subcategories via atom spectrumDec 29 2011Sep 13 2012In this paper, we introduce the atom spectrum of an abelian category as a topological space consisting of all the equivalence classes of monoform objects. In terms of the atom spectrum, we give a classification of Serre subcategories of an arbitrary noetherian ... More
Thick subcategories over Gorenstein local rings that are locally hypersurfaces on the punctured spectraSep 14 2011Let R be a Gorenstein local ring which is locally a hypersurface on the punctured spectrum. In this paper, we classify thick subcategories of the bounded derived category of finitely generated R-modules. Moreover, using this classification, we also classify ... More
Extension groups between atoms and objects in locally noetherian Grothendieck categoryMay 14 2012Jan 09 2015We define the extension group between an atom and an object in a locally noetherian Grothendieck category as a module over a skew field. We show that the dimension of the i-th extension group between an atom and an object coincides with the i-th Bass ... More
Classifying subcategories of modules over a commutative noetherian ringAug 01 2008Let R be a quotient ring of a commutative coherent regular ring by a finitely generated ideal. Hovey gave a bijection between the set of coherent subcategories of the category of finitely presented R-modules and the set of thick subcategories of the derived ... More
On localizing subcategories of derived categoriesDec 12 2007Jul 14 2009Let A be a commutative noetherian ring. In this paper, we interpret localizing subcategories of the derived category of A by using subsets of Spec A and subcategories of the category of A-modules. We unify theorems of Gabriel, Neeman and Krause.
On the Wu invariants for immersions of a graph into the planeAug 21 2009Feb 14 2010We give an explicit calculation of the Wu invariants for immersions of a finite graph into the plane and classify all generic immersions of a graph into the plane up to regular homotopy by the Wu invariant. This result is a generalization of the fact ... More
Homotopy on spatial graphs and generalized Sato-Levine invariantsOct 19 2007Dec 27 2008Edge-homotopy and vertex-homotopy are equivalence relations on spatial graphs which are generalizations of Milnor's link-homotopy. Fleming and the author introduced some edge (resp. vertex)-homotopy invariants of spatial graphs by applying the Sato-Levine ... More
Syzygy modules with semidualizing or G-projective summandsJan 21 2005Let R be a commutative Noetherian local ring with residue class field k. In this paper, we mainly investigate direct summands of the syzygy modules of k. We prove that R is regular if and only if some syzygy module of k has a semidualizing summand. After ... More
The gonality and the Clifford index of curves on a toric surfaceOct 19 2013We determine the gonality and the Clifford index for curves on a compact smooth toric surface. Moreover, it is shown that their gonality are computed by pencils on the ambient surface. From the geometrical view point, this means that the gonality can ... More
Asymptotic Profiles for wave equations with strong dampingFeb 25 2014We consider the Cauchy problem in ${\bf R}^{n}$ for strongly damped wave equations. We derive asymptotic profiles of these solutions with weighted $L^{1,1}({\bf R}^{n})$ data by using a method introduced in [10].
Equivalences between weight modules via $\mathcal{N}=2$ coset constructionsMay 08 2016Sep 17 2016In this paper we introduce a variant of weight modules for certain conformal vertex superalgebras as an appropriate framework of the $\mathcal{N}=2$ supersymmetric coset construction. We call them weight-wise admissible modules. Motivated by the work ... More
Tilting modules of affine quasi-hereditary algebrasOct 09 2016We discuss tilting modules of affine quasi-hereditary algebras. We present an existence theorem of indecomposable tilting modules when the algebra has a large center and use it to deduce a criterion for an exact functor between two affine highest weight ... More
Prior Emission Model for X-ray Plateau Phase of Gamma-Ray Burst AfterglowsOct 07 2008Dec 15 2008The two-component emission model to explain the plateau phase of the X-ray afterglows of gamma-ray bursts (GRBs) is proposed. One component, which is responsible for the plateau and subsequent normal decay phase of the X-ray afterglow, is the prior emission ... More
The existence of finitely generated modules of finite Gorenstein injective dimensionJun 13 2005In this note, we study commutative Noetherian local rings having finitely generated modules of finite Gorenstein injective dimension. In particular, we consider whether such rings are Cohen-Macaulay.
Direct summands of syzygy modules of the residue class fieldMar 07 2007Let R be a commutative Noetherian local ring. This paper deals with the problem asking whether R is Gorenstein if the n-th syzygy of the residue field of R has a nontrivial direct summand of finite G-dimension for some n. It is proved that if n is at ... More
Discovery of a new subparsec counterjet in NGC 1275: the inclination angle and the environmentSep 13 2016We report the detection of a new feature at the centre of NGC 1275 in the Perseus cluster, hosting the radio source 3C 84. This feature emerges 2 mas (~ 0.7 pc) north of the central core in recent 15 and 43 GHz VLBA images, and seems to be the counterjet ... More
Discrete soliton equations and convergence acceleration algorithmsNov 07 1995Some of the well-known convergence acceleration algorithms, when viewed as two-variable difference equations, are equivalent to discrete soliton equations. It is shown that the $\eta-$algorithm is nothing but the discrete KdV equation. In addition, one ... More
Multi-band Eilenberger theory of superconductivity: Systematic low-energy projectionJul 22 2015Apr 20 2016We propose the general multi-band quasiclassical Eilenberger theory of superconductivity to describe quasiparticle excitations in inhomogeneous systems. With the use of low-energy projection matrix, the $M$-band quasiclassical Eilenberger equations are ... More
Determination of the pairing state in iron-based superconductors through neutron scatteringMar 03 2011Jul 11 2011We calculate the spin susceptibility in the s_{+-} and s_{++} superconducting states of the iron pnictides using the effective five orbital model and considering the quasiparticle damping. For the experimentally evaluated magnitude of the quasiparticle ... More
Q-scan-analysis of the neutron scattering in iron-based superconductorsJan 12 2012May 28 2012We propose a way to determine the pairing state of the iron pnictide superconductors exploiting the momentum (Q) scan of the neutron scattering data. We investigate the spin susceptibility in the s+- and s++ superconducting states for various doping levels ... More
Mass-scaling replica-exchange molecular dynamics optimizes computational resources with simpler algorithmMay 14 2014May 29 2014We develop a novel method of replica-exchange molecular dynamics (REMD) simulation, mass-scaling REMD (MSREMD) method, which improves trajectory accuracy at high temperatures, and thereby contributes to numerical stability. In addition, the MSREMD method ... More
Electromagnetic Response of a $k_x\pm ik_y$ Superconductor: Effect of Order Parameter Collective ModesMar 14 2000Effects of order parameter collective modes on electromagnetic response are studied for a clean spin-triplet superconductor with $k_x\pm ik_y$ orbital symmetry, which has been proposed as a candidate pairing symmetry for Sr$_2$RuO$_4$. It is shown that ... More
The domain-wall model in an asymptotic-free dynamicsNov 30 1997We investigate a possibility that the rough gauge problem, which have appeared to be a main reason for failures of lattice chiral gauge theories, is cured by an asymptotic-free dynamics. Taking the domain-wall model in 2(+1) dimensions with SU(2) gauge ... More
Domain-wall fermions with U(1) dynamical gauge fields in (4+1)-dimensionsSep 02 1996We carry out a numerical simulation of a domain-wall model in (4+1) dimensions, in the presence of a quenched U(1) dynamical gauge field only in an extra dimension, corresponding to the weak coupling limit of a (4-dimensional) physical gauge coupling. ... More
Direct/indirect detection signatures of nonthermally produced dark matterJul 10 2008Sep 22 2008We study direct and indirect detection possibilities of neutralino dark matter produced non-thermally by e.g. the decay of long-lived particles, as is easily implemented in the case of anomaly or mirage mediation models. In this scenario, large self-annihilation ... More
Chiral zero modes on the domain-wall model in 4+1 dimensionsOct 24 1996We investigate an original domain-wall model in 4+1 dimensions numerically in the presence of U(1) dynamical gauge field only in an extra dimension, corresponding to a weak coupling limit of 4-dimensional physical gauge coupling. Using a quenched approximation ... More
Comment on arXiv:1105.6233 entitled "Neutron-Inelastic-Scattering Peak by Dissipationless Mechanism in the s++-wave State in Iron-based Superconductors" by S. Onari and H. KontaniJun 13 2011Recently, Onari and Kontani submitted a paper [arXiv:1105.6233] which criticizes our recent theoretical study [arXiv:1103.0586] on the neutron scattering experiment as a probe for determining the superconducting gap in the iron pnictides. In their paper, ... More
Predictions via large theta13 from cascadesJun 29 2011Aug 11 2011We investigate a relation among neutrino observables, three mixing angles and two mass squared differences, from a cascade texture of neutrino mass matrix. We show an allowed region of the correlation by use of current data of neutrino oscillation experiments. ... More
Pre-reheating Magnetogenesis in the Kinetic Coupling ModelFeb 18 2016Apr 04 2016Recent blazar observations provide growing evidence for the presence of magnetic fields in the extragalactic regions. While a natural speculation is to associate the production to inflationary physics, it has been known that magnetogenesis solely from ... More
Quantum Benchmark via an Uncertainty Product of Canonical VariablesApr 09 2014Mar 27 2015We present an uncertainty-relation-type quantum benchmark for continuous-variable (CV) quantum channels that works with an input ensemble of Gaussian distributed coherent states and homodyne measurements. It determines an optimal trade-off relation between ... More
Superconducting proximity effect on a two-dimensional Dirac electron systemJan 21 2014The superconducting proximity effect on two-dimensional massless Dirac electrons is usually analyzed using a simple model consisting of the Dirac Hamiltonian and an energy-independent pair potential. Although this conventional model is plausible, it is ... More
Strong-Coupling Effects and Single-Particle Properties in an Ultracold Fermi Gas with Mass ImbalanceJul 10 2013We investigate single-particle properties of a strongly interacting ultracold Fermi gas with mass imbalance. Using an extended $T$-matrix theory, we calculate the density of states, as well as the single-particle spectral weight, in the unitarity limit ... More
Outward Motion of Porous Dust Aggregates by Stellar Radiation Pressure in Protoplanetary DisksNov 18 2014We study the dust motion at the surface layer of protoplanetary disks. Dust grains in surface layer migrate outward due to angular momentum transport via gas-drag force induced by the stellar radiation pressure. In this study, we calculate mass flux of ... More
On the Subclasses in Swift Long Gamma-Ray Bursts: A Clue to Different Central EnginesNov 06 2013Dec 06 2013Analyzing light curves of a complete sample of bright Swift long gamma-ray bursts (LGRBs) of which the peak photon fluxes constructed with the bin width of 1 second in the Swift 15-350 keV energy band exceed 2.6 photons cm$^{-2}$s$^{-1}$, we confirm that ... More
Gravitational potential and X-ray luminosities of early-type galaxies observed with XMM-Newton and ChandraMar 14 2009Mar 31 2009We study dark matter content in early-type galaxies and investigate whether X-ray luminosities of early-type galaxies are determined by the surrounding gravitational potential. We derived gravitational mass profiles of 22 early-type galaxies observed ... More
More anomaly-free models of six-dimensional gauged supergravityDec 01 2005Sep 04 2006We construct a huge number of anomaly-free models of six-dimensional N = (1,0) gauged supergravity. The gauge groups are products of U(1) and SU(2), and every hyperino is charged under some of the gauge groups. It is also found that the potential may ... More
Finite-Size Effects for Dyonic Giant MagnonsJan 06 2008Oct 15 2008We compute finite-size corrections to dyonic giant magnons in two ways. One is by examining the asymptotic behavior of helical strings of hep-th/0609026 as elliptic modulus k goes to unity, and the other is by applying the generalized Luscher formula ... More
Maximal Cohen-Macaulay approximations and Serre's conditionDec 27 2014This paper studies the relationship between Serre's condition $(\R_n)$ and Auslander--Buchweitz's maximal Cohen--Macaulay approximations. It is proved that a Gorenstein local ring satisfies $(\R_n)$ if and only if every maximal Cohen--Macaulay module ... More
Classification of resolving subcategories and grade consistent functionsFeb 25 2012Jun 14 2013We classify certain resolving subcategories of finitely generated modules over a commutative noetherian ring R by using integer-valued functions on Spec R. As an application we give a complete classification of resolving subcategories when R is a locally ... More
Algorithmic canonical stratifications of simplicial complexesAug 20 2018We introduce a new algorithm for the structural analysis of finite abstract simplicial complexes based on local homology. Through an iterative and top-down procedure, our algorithm computes a stratification $\pi$ of the poset $P$ of simplices of a simplicial ... More
Generators and dimensions of derived categoriesJun 01 2011Oct 27 2011Several years ago, Bondal, Rouquier and Van den Bergh introduced the notion of the dimension of a triangulated category, and Rouquier proved that the bounded derived category of coherent sheaves on a separated scheme of finite type over a perfect field ... More
Upper bounds for dimensions of singularity categoriesMar 08 2012This paper gives upper bounds for the dimension of the singularity category of a Cohen-Macaulay local ring with an isolated singularity. One of them recovers an upper bound given by Ballard, Favero and Katzarkov in the case of a hypersurface.
The radius of a subcategory of modulesNov 12 2011Sep 23 2013We introduce a new invariant for subcategories X of finitely generated modules over a local ring R which we call the radius of X. We show that if R is a complete intersection and X is resolving, then finiteness of the radius forces X to contain only maximal ... More
New Detections of Galactic Molecular Absorption Systems toward ALMA Calibrator SourcesOct 16 2015We report on Atacama Large Millimeter/submillimeter Array (ALMA) detections of molecular absorption lines in Bands 3, 6 and 7 toward four radio-loud quasars, which were observed as the bandpass and complex gain calibrators. The absorption systems, three ... More
Nuclear magnetic relaxation rates of unconventional superconductivity in doped topological insulatorsMay 26 2016We study the temperature dependence of nuclear magnetic relaxation (NMR) rates to detect a sign of topological superconductivity in doped topological insulators, such as $M$($=$Cu,Nb,Sr)$_{x}$Bi$_{2}$Se$_{3}$ and Sn$_{1-x}$In$_{x}$Te. The Hebel-Slichter ... More
Efficient-phase-encoding protocols for continuous-variable quantum key distribution using coherent states and postselectionAug 18 2006We propose efficient-phase-encoding protocols for continuous-variable quantum key distribution using coherent states and postselection. By these phase encodings, the probability of basis mismatch is reduced and total efficiency is increased. We also propose ... More
Security of Continuous-variable quantum cryptography using coherent states: Decline of postselection advantageJun 23 2005We investigate the security of continuous-variable (CV) quantum key distribution (QKD) using coherent states in the presence of quadrature excess noise. We consider an eavesdropping attack which uses a linear amplifier and beam splitter. This attack makes ... More
Spin and orbital ordering in double-layered manganitesApr 29 1999We study theoretically the phase diagram of the double-layered perovskite manganites taking into account the orbital degeneracy, the strong Coulombic repulsion, and the coupling with the lattice deformation. Observed spin structural changes as the increased ... More
Testing two-component jet models of GRBs with orphan afterglowsApr 18 2010May 13 2011In the \swift era, two-component jet models were introduced to explain the complex temporal profiles and the diversity of early afterglows. In this paper, we concentrate on the two-component jet model; first component is the conventional afterglow and ... More
Gravitational Wave Probe of High Supersymmetry Breaking ScaleJan 31 2012Apr 02 2012A supersymmetric standard model with heavier scalar particles is very interesting from various viewpoints, especially Higgs properties. If the scalar mass scale is O(10-10^4) TeV, the standard model-like Higgs with mass around 125 GeV, which is implied ... More
Path of the current flow at the metal contacts of graphene field-effect transistors with distorted transfer characteristicsJul 24 2014Graphene field-effect transistors with source/drain contacts made of metals that can be easily oxidized such as ferromagnetic metals often display a double dip structure in the transfer characteristics because of charge density depinning at the contacts. ... More
Relationship Between Gravity and Gauge Scattering in the High Energy LimitOct 30 2012Nov 12 2012Investigations of high-energy graviton-graviton and gluon-gluon scattering are performed in the leading eikonal approximation for the kinematic regime of large center of mass energy and low momentum transfer. We find a double copy relation between the ... More
Sequential optimizing investing strategy with neural networksFeb 11 2010In this paper we propose an investing strategy based on neural network models combined with ideas from game-theoretic probability of Shafer and Vovk. Our proposed strategy uses parameter values of a neural network with the best performance until the previous ... More
Lensing reconstruction from a patchwork of polarization mapsMay 26 2014Aug 23 2014The lensing signals involved in CMB polarization maps have already been measured with ground-based experiments such as SPTpol and POLARBEAR, and would become important as a probe of cosmological and astrophysical issues in the near future. Sizes of polarization ... More
Large time behaivor of global solutions to nonlinear wave equations with frictional and viscoelastic damping termsMay 23 2016In this paper, we study the Cauchy problem for a nonlinear wave equation with frictional and viscoelastic damping terms. As is pointed out by [8], in this combination, the frictional damping term is dominant for the viscoelastic one for the global dynamics ... More
Structure of irreducible homomorphisms to/from free modulesJun 08 2016The primary goal of this paper is to investigate the structure of irreducible monomorphisms to and irreducible epimorphisms from finitely generated free modules over a noetherian local ring. Then we show that over such a ring, self-vanishing of Ext and ... More
Endofunctors of singularity categories characterizing Gorenstein ringsMay 18 2014In this paper, we prove that certain contravariant endofunctors of singularity categories characterize Gorenstein rings.
Coherent IC-sheaves on type $A_{n}$ affine Grassmannians and dual canonical basis of affine type $A_{1}$Jan 17 2019Feb 27 2019The convolution ring $K^{GL_n(\mathcal{O})\rtimes\mathbb{C}^\times}(\mathrm{Gr}_{GL_n})$ was identified with a quantum unipotent cell of the loop group $LSL_2$ in [Cautis-Williams, arXiv:1801.08111]. We identify the basis formed by the classes of irreducible ... More
Homotopy on spatial graphs and the Sato-Levine invariantSep 01 2005Sep 23 2008Edge-homotopy and vertex-homotopy are equivalence relations on spatial graphs which are generalizations of Milnor's link-homotopy. We introduce some edge (resp. vertex)-homotopy invariants of spatial graphs by applying the Sato-Levine invariant for the ... More
On Conway-Gordon type theorems for graphs in the Petersen familySep 10 2012Jul 11 2013For every spatial embedding of each graph in the Petersen family, it is known that the sum of the linking numbers over all of the constituent 2-component links is congruent to 1 modulo 2. In this paper, we give an integral lift of this formula in terms ... More
Regular projections of graphs with at most three double pointsAug 29 2008May 07 2009A generic immersion of a planar graph into the 2-space is said to be knotted if there does not exist a trivial embedding of the graph into the 3-space obtained by lifting the immersion with respect to the natural projection from the 3-space to the 2-space. ... More
On Large Homomorphisms of Local RingsMar 10 2019We study ideals in a local ring $R$ whose quotient rings induce large homomorphisms of local rings. We characterize such ideals over complete intersections, Koszul rings, and over some classes of Golod rings.
A subspecies of region crossing change, region freeze crossing changeJun 22 2016We introduce a local move on a link diagram named a region freeze crossing change which is close to a region crossing change, but not the same. We study similarity and difference between region crossing change and region freeze crossing change.
Rational orbits of the space of pairs of exceptional Jordan algebrasMar 02 2016Let $k$ be a field of characteristic not equal to $2,3$, $\mathbb{O}$ an octonion over $k$ and $\mathcal{J}$ the exceptional Jordan algebra defined by $\mathbb{O}$. We consider the prehomogeneous vector space $(G,V)$ where $G=GE_6\times \mathrm{GL}(2)$ ... More
Schmidt-number benchmark for genuine quantum memories and gatesFeb 02 2012We propose to apply the notion of the Schmidt number in order to show that a quantum memory or gate process is capable of maintaining a genuine multi-level quantum coherence. We present a simple criterion in terms of an average gate fidelity with respect ... More
Band-Renormalization Effects and Predominant Antiferromagnetic Order in Two-Dimensional Hubbard ModelMay 15 2016Band renormalization effects (BRE) are comprehensively studied for a mixed state of dx2-y2-wave superconducting (d-SC) and antiferromagnetic (AF) orders, in addition to simple d-SC, AF, and normal (paramagnetic) states, by applying a variational Monte ... More