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
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
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
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
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
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
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.
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
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.
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
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
A remark on the Wiener-Ikehara Tauberian theoremJun 02 2014In this paper we point out that the proof of Kable's extension of the Wiener-Ikehara Tauberian theorem can be applied to the case where the Dirichlet series has a pole of order "$l / m$" without much modification (Kable proved the case $l = 1$).
A characterization of modules locally of finite injective dimensionSep 25 2006In this note, finite modules locally of finite injective dimension over commutative Noetherian rings are characterized in terms of vanishing of Ext modules.
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
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
Conductance of telescoped double-walled nanotubes from perturbation calculationsMar 23 2009Aug 06 2010In a telescoped double-walled nanotube (TDWNT), with the inner tube partially extracted from the outer tube, the total current is forced to flow between the layers. Considering the interlayer Hamiltonian as a perturbation, we can obtain an analytic formula ... 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].
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
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
Delta edge-homotopy invariants of spatial graphs via disk-summing the constituent knotsMar 12 2007Aug 20 2007In this paper we construct some invariants of spatial graphs by disk-summing the constituent knots and show the delta edge-homotopy invariance of them. As an application, we show that there exist infinitely many slice spatial embeddings of a planar graph ... 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
Remarks on modules approximated by G-projective modulesSep 27 2005Let $R$ be a commutative Noetherian Henselian local ring. Denote by $\mathrm{mod} R$ the category of finitely generated $R$-modules, and by ${\mathcal G}$ the full subcategory of $\mathrm{mod} R$ consisting of all G-projective $R$-modules. In this paper, ... More
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
Relation between dispersion lines and conductance of telescoped armchair double-wall nanotubes analyzed using perturbation formulas and first-principles calculationsMar 15 2012Oct 18 2012The Landauer's formula conductance of the telescoped armchair nanotubes is calculated with the Hamiltonian defined by first-principles calculations (SIESTA code). Herein, partially extracting the inner tube from the outer tube is called 'telescoping'. ... More
Resonant spin current in nanotube double junctionsDec 02 2002Zero bias conductance per spin of nanotube double junction (NTDJ) is investigated theoretically using the tight binding model, unrestricted Hartree-Fock approximation and non-equilibrium Green's functions. NTDJ consists of two metallic nanotubes joined ... More
Backward diode composed of a metallic and semiconducting nanotubeJun 04 2001The conditions necessary for a nanotube junction connecting a metallic and semiconducting nanotube to rectify the current are theoretically investigated. A tight binding model is used for the analysis, which includes the Hartree-Fock approximation and ... 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.
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
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
Modules in resolving subcategories which are free on the punctured spectrumJan 09 2009Let R be a commutative noetherian local ring, and let X be a resolving subcategory of the category of finitely generated R-modules. In this paper, we study modules in X by relating them to modules in X which are free on the punctured spectrum of R. We ... More
Classification of categorical subspaces of locally noetherian schemesMay 18 2014Mar 14 2016We classify the prelocalizing subcategories of the category of quasi-coherent sheaves on a locally noetherian scheme. In order to give the classification, we introduce the notion of a local filter of subobjects of the structure sheaf. The essential part ... More
A characterization of certain irreducible symplectic 4-foldsOct 18 2002We give a characterization of irreducible symplectic fourfolds which are given as Hilbert scheme of points on a K3 surface.
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
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
Nonthermal dark matter in mirage mediationSep 25 2007Oct 24 2007In mirage-mediation models there exists a modulus field whose mass is O(1000) TeV and its late-decay may significantly change the standard thermal relic scenario of the dark matter. We study nonthermal production of the dark matter directly from the modulus ... More
Effect of Helium Sedimentation on X-ray Measurements of Galaxy ClustersAug 27 2008Nov 13 2008The uniformity of the helium-to-hydrogen abundance ratio in X-ray emitting intracluster medium (ICM) is one of the commonly adopted assumptions in X-ray analyses of galaxy clusters and cosmological constraints derived from these measurements. In this ... 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
Capture of planetesimals by waning circumplanetary gas disksApr 28 2016When gas giant protoplanets grow sufficiently massive, circumplanetary disks would form. While solid bodies captured by the circumplanetary disks likely contribute to the growth of the planets and regular satellites around them, some of captured bodies ... 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
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
$\triangle Y$-exchanges and the Conway-Gordon theoremsApr 05 2011Sep 23 2011Conway-Gordon proved 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 the Arf invariants ... 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
A Perspective on Classical Strings from Complex Sine-Gordon SolitonsSep 04 2006Oct 02 2007We study a family of classical string solutions with large spins on R x S^3 subspace of AdS_5 x S^5 background, which are related to Complex sine-Gordon solitons via Pohlmeyer's reduction. The equations of motion for the classical strings are cast into ... 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
Speed of Sound in the Mass Varying Neutrinos ScenarioJan 06 2006Jan 30 2006We discuss about the speed of sound squared in the Mass Varying Neutrinos scenario (MaVaNs). Recently, it was argued that the MaVaNs has a catastrophic instability which is the emergence of an imaginary speed of sound at the non-relativistic limit of ... 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
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
Products of Greek letter elements dug up from the third Morava stabilizer algebraFeb 12 2012Oka and the second author considered the cohomology of the second Morava stabilizer algebra to study nontriviality of the products of beta elements of the stable homotopy groups of spheres. In this paper, we use the cohomology of the third Morava stabilizer ... 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
Diffusion Monte Carlo methods applied to Hamaker Constant evaluationsMay 02 2016We applied diffusion Monte Carlo (DMC) methods to evaluate Hamaker constants of liquids for wettabilities, with practical size of a liquid molecule, Si$_6$H$_{12}$ (cyclohexasilane). The evaluated constant would be justified in the sense that it lies ... 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
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
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
Dark Energy and Neutrino Model in SUSYOct 26 2006Oct 30 2006We discuss the effect of the supersymmetry breaking on the Mass Varying Neutrinos(MaVaNs) scenario. Especially, the effect mediated by the gravitational interaction between the hidden sector and the dark energy sector is studied. A model including a chiral ... More
Model of Mass Varying Neutrinos in SUSYJul 12 2005Nov 10 2005We discuss the mass varying neutrino scenario in the supersymmetric theory. In the case of the model with the single superfield, one needs the soft SUSY breaking terms or the $\mu$ term. However, fine-tunings of some parameters are required to be consistent ... 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
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
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
Winding number and non-BPS bound states of walls in nonlinear sigma modelsMar 15 2002May 13 2002Non-supersymmetric multi-wall configurations are generically unstable. It is proposed that the stabilization in compact space can be achieved by introducing a winding number into the model. A BPS-like bound is studied for the energy of configuration with ... More
Hetero pairing and component-dependent pseudogap phenomena in an ultracold Fermi gas with mass imbalanceJul 27 2014We investigate the superfluid phase transition and single-particle excitations in the BCS (Bareen-Cooper-Schrieffer)-BEC (Bose-Einstein condensation) crossover regime of an ultracold Fermi gas with mass imbalance. In our recent paper [R. Hanai, et. al., ... More
Measurement of spin pumping voltage separated from extrinsic microwave effectsJul 16 2016Conversions between spin and charge currents are core technologies in recent spintronics. In this article, we provide methods for estimating inverse spin Hall effects (ISHEs) induced by using microwave-driven spin pumping (SP) as a spin-current generator. ... More
Single-Letter Characterization of Epsilon-Capacity for Mixed Memoryless ChannelsJul 01 2014For the class of mixed channels decomposed into stationary memoryless channels, single-letter characterizations of the $\varepsilon$-capacity have not been known except for restricted classes of channels such as the regular decomposable channel introduced ... More
Negative anomalous dimensions in N=4 SYMMar 20 2015Aug 05 2015We elucidate aspects of the one-loop anomalous dimension of $so(6)$-singlet multi-trace operators in $\mathcal{N}=4\ SU(N_c)$ SYM at finite $N_c$. First, we study how $1/N_c$ corrections lift the large $N_c$ degeneracy of the spectrum, which we call the ... More
Renormalization Group Improved Higgs Inflation with a Running Kinetic TermMar 24 2016Jul 20 2016We study a Higgs inflation model with a running kinetic term, taking account of the renormalization group evolution of relevant coupling constants. Specifically we study two types of the running kinetic Higgs inflation, where the inflaton potential is ... More
Expansion of a Bose-Einstein Condensate with VorticesNov 30 2013The expansion of Bose-Einstein condensates (BECs) is numerically studied. Usually, the aspect ratio of a condensate is inverted due to the anisotropy of the uncertainty principle. In turbulent BECs, however, the aspect ratio remains constant. The reason ... More
A good universal weight for nonconventional ergodic averages in normMar 30 2015Sep 02 2015We will show that the sequence appearing in the double recurrence theorem is a good universal weight for the Furstenberg averages. That is, given a system $(X, \mathcal{F}, \mu, T)$ and bounded functions $f_1, f_2 \in L^\infty(\mu)$, there exists a set ... More
Extension of Wiener-Wintner double recurrence theorem to polynomialsAug 25 2014Sep 02 2015We extend our result on the convergence of double recurrence Wiener-Wintner averages to the case where we have a polynomial exponent. We will show that there exists a single set of full measure for which the averages \[ \frac{1}{N} \sum_{n=1}^N f_1(T^{an}x)f_2(T^{bn}x)\phi(p(n)) ... More
Fast energy decay for wave equations with variable damping coefficients in the 1-D half lineJun 16 2015We derive fast decay estimates of the total energy for wave equations with localized variable damping coefficients, which are dealt with in the one dimensional half line $(0,\infty)$. The variable damping coefficient vanishes near the boundary $x = 0$, ... More
Auslander-Reiten conjecture and Auslander-Reiten dualityDec 28 2011Feb 08 2013Motivated by a result of Araya, we extend the Auslander-Reiten duality theorem to Cohen-Macaulay local rings. We also study the Auslander-Reiten conjecture, which is rooted in Nakayama's work on finite dimensional algebras. One of our results detects ... 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
Rotational motion of magnon and thermal Hall effectJun 10 2011Due to the Berry curvature in momentum space, the magnon wavepacket undergoes two types of orbital motions in analogy with the electron system: the self-rotation motion and a motion along the boundary of the sample (edge current). The magnon edge current ... More
Theoretical prediction of rotating magnon wavepacket in ferromagnetsMar 07 2011Apr 28 2011We theoretically show that the magnon wavepacket has a rotational motion in two ways; a self-rotation and a motion along the boundary of the sample (edge current). They are similar to cyclotron motion of electrons, but unlike electrons the magnons have ... 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
Gate-controlled ultraviolet photo-etching of graphene edgesNov 14 2013The chemical reactivity of graphene under ultraviolet (UV) light irradiation is investigated under positive and negative gate electric fields. Graphene edges are selectively etched when negative gate voltages are applied, while the reactivity is significantly ... More
Relation between the transmission rates and the wave functions in the carbon nanotube junctionsMar 18 1999Electron transmission and wave functions through junctions with a pair of a pentagonal defect and a heptagonal defect connecting two metallic carbon nanotubes are analyzed by the analytical calculation with the effective mass equation. The energy region ... More
Substituent-Controlled Reversible Switching of Charge-Injection-Barrier Heights at Metal/Organic-Semiconductor Contacts Modified with Disordered Molecular MonolayersAug 03 2016Electrically stimulated switching of a charge injection barrier at the interface between an organic semiconductor and an electrode modified with a disordered monolayer (DM) is studied by using various benzenethiol derivatives as DM molecules. The switching ... More
Variable-Length Coding with Cost Allowing Non-Vanishing Error ProbabilityOct 06 2016We derive a general formula of the minimum achievable rate for fixed-to-variable length coding with a regular cost function by allowing the error probability up to a constant $\varepsilon$. For a fixed-to-variable length code, we call the set of source ... More
Conway-Gordon type theorem for the complete four-partite graph $K_{3,3,1,1}$Nov 17 2012May 08 2014We give a Conway-Gordon type formula for invariants of knots and links in a spatial complete four-partite graph $K_{3,3,1,1}$ in terms of the square of the linking number and the second coefficient of the Conway polynomial. As an application, we show ... More
Renormalization of two-dimensional XQCDOct 15 2015Recently, Kaplan proposed an interesting extension of QCD named Extended QCD or XQCD with bosonic auxiliary fields [1]. While its partition function is kept exactly the same as that of QCD, XQCD naturally contains properties of low-energy hadrons. We ... More
Security of quantum cryptography using balanced homodyne detectionMay 31 2002Feb 27 2003In this paper we investigate the security of a quantum cryptographic scheme which utilizes balanced homodyne detection and weak coherent pulse (WCP). The performance of the system is mainly characterized by the intensity of the WCP and postselected threshold. ... More
Jahn-Teller effect and Electron correlation in manganitesFeb 18 2002Jahn-Teller (JT) effect both in the absence and presence of the strong Coulomb correlation is studied theoretically focusing on the reduction $\Delta K$ of the kinetic energy gain which is directly related to the spin wave stiffness. Without the Coulomb ... More
Complex orbital state in manganitesMay 27 2000The $e_g$-orbital states with complex coefficients of the linear combination of $x^2-y^2$ and $3z^2-r^2$ are studied for the ferromagnetic state in doped manganites. Especially the focus is put on the competition among uniform complex, staggered complex, ... More
Two-Dimensional Island Shape Determined by DetachmentMay 25 2007Effect of an anisotropic detachment on a heteroepitaxial island shape is studied by means of a kinetic Monte Carlo simulation of a square lattice gas model. Only with molecular deposition followed by surface diffusion, islands grow in a ramified dendritic ... More