Results for "Takahiro Misawa"

total 1466took 0.11s
One-dimensionalization by Geometrical Frustration in the Anisotropic Triangular Lattice of the 5d Quantum Antiferromagnet Ca3ReO5Cl2Apr 12 2019We report on the emergence of antiferromagnetic spin chains from two-dimensionally aligned spins on the anisotropic triangular lattice (ATL) in the insulating calcium rhenium oxychloride Ca3ReO5Cl2. The compound contains Re6+ ions each with one unpaired ... More
Quantum criticality around metal-insulator transitions of strongly correlated electronsDec 26 2006Quantum criticality of metal-insulator transitions in correlated electron systems is shownto belong to an unconventional universality class with violation of Ginzburg-Landau-Wilson(GLW) scheme formulated for symmetry breaking transitions. This unconventionality ... More
Origin of high-Tc superconductivity in doped Hubbard models and their extensions: Roles of uniform charge fluctuationsJun 06 2013Oct 01 2014Doped Hubbard model is a simple model for the high-Tc cuprate superconductors, while its ground state remains a challenge. Here, by performing state-of-the-art variational Monte Carlo calculations for the strong-coupling Hubbard model, we find evidences ... More
Superconductivity and its mechanism in an ab initio model for electron-doped LaFeAsOSep 23 2014Two families of high temperature superconductors whose critical temperatures are higher than 50K are known. One is the copper oxides and the other is the iron-based superconductors. Comparisons of mechanisms between these two in terms of common ground ... More
Nonequilibrium relaxation study of the anisotropic antiferromagnetic Heisenberg model on the triangular latticeApr 27 2010Effect of exchange anisotropy on the relaxation time of spin and vector chirality is studied for the antiferromagnetic classical Heisenberg model on the triangular lattice by using the nonequilibrium relaxation Monte Carlo method. We identify the Berezinskii-Kosterlitz-Thouless ... More
Finite-Temperature Signatures of Spin Liquids in Frustrated Hubbard ModelAug 31 2016Finite-temperature properties of the frustrated Hubbard model are theoretically examined by using the recently proposed thermal pure quantum state, which is an unbiased numerical method for finite-temperature calculations. By performing systematic calculations ... More
Quantum Tricriticality in Antiferromagnetic Ising Model with Transverse Field: A Quantum Monte-Carlo StudyJul 31 2015Quantum tricriticality of a $J_1$-$J_2$ antiferromagnetic Ising model on a square lattice is studied using the mean-field (MF) theory, scaling theory, and the unbiased world-line quantum Monte-Carlo (QMC) method based on the Feynman path integral formula. ... More
Spin Fluctuation Theory for Quantum Tricritical Point Arising in Proximity to First-Order Phase Transitions: Applications to Heavy-Fermion Systems, YbRh2Si2, CeRu2Si2, and beta-YbAlB4May 13 2009We propose a phenomenological spin fluctuation theory for antiferromagnetic quantum tricritical point (QTCP), where the first-order phase transition changes into the continuous one at zero temperature. Under magnetic fields, ferromagnetic quantum critical ... More
Unconventional quantum criticality emerging as a new common language of transition-metal compounds, heavy-fermion systems, and organic conductorsSep 03 2009Aug 21 2010We analyze and overview several different unconventional quantum criticalities. One origin of the unconventionality is the proximity to first-order transitions. The border between the first-order and continuous transitions is described by a quantum tricritical ... More
Tricritical Behavior in Charge-Order SystemMay 27 2006Tricritical point in charge-order systems and its criticality are studied for a microscopic model by using the mean-field approximation and exchange Monte Carlo method in the classical limit as well as by using the Hartree-Fock approximation for the quantum ... More
Charge Order in a Two-Dimensional Kondo Lattice ModelMar 13 2013The possibility of charge order is theoretically examined for the Kondo lattice model in two dimensions, which does not include bare repulsive interactions. Using two complementary numerical methods, we find that charge order appears at quarter filling ... More
Quantum Metamagnetic Transitions Induced by Changes in Fermi-Surface Topology -Applications to a Weak Itinerant-Electron Ferromagnet;ZrZn_2Mar 16 2007We clarify that metamagnetic transitions in three dimensions show unusual properties as quantum phase transitions if they are accompanied by changes in Fermi-surface topology. An unconventional universality deeply affected by the topological nature of ... More
Quantum and Topological Criticalities of Lifshitz Transition in Two-Dimensional Correlated Electron SystemsAug 21 2006Aug 22 2006We study electron correlation effects on quantum criticalities of Lifshitz transitions at zero temperature, using the mean-field theory based on a preexisting symmetry-broken order, in two-dimensional systems. In the presence of interactions, Lifshitz ... More
Quantum critical "opalescence" around metal-insulator transitionsApr 16 2006Jul 16 2006Divergent carrier-density fluctuations equivalent to the critical opalescence of gas-liquid transitions emerge around a metal-insulator critical point at a finite temperature. In contrast to the gas-liquid transitions, however, the critical temperature ... More
Charge Order with a Noncoplanar Triple-Q Magnetic Order on a Cubic LatticeOct 08 2013Ground state of the periodic Anderson model on a cubic lattice is investigated by mean-field calculations, with focusing on the possibility of charge ordering. We show that three different charge-ordered phases appear at 3/2 filling, which are accompanied ... More
Ab initio Evidence for Strong Correlation Associated with Mott Proximity in Iron-based SuperconductorsDec 20 2011We predict that iron-based superconductors discovered near d6 configuration (5 Fe 3d orbitals filled by 6 electrons) is located on the foot of an unexpectedly large dome of correlated electron matter centered at the Mott insulator at d5 (namely, half ... More
Magnetization Step in Spatially Distorted Heisenberg Kagome AntiferromagnetsApr 14 2010Motivated by recent experiment for volborthite, a typical spin-1/2 antiferromagnet with kagome lattice structure, we study magnetization process of classical Heisenberg model on a spatially distorted kagome lattice using Monte Carlo (MC) method. We find ... More
Magnetic Properties of Ab initio Model for Iron-Based Superconductors LaFeAsOJun 24 2010By using variational Monte Carlo method, we examine an effective low-energy model for LaFeAsO derived from an ab initio downfolding scheme. We show that quantum and many-body fluctuations near a quantum critical point largely reduce the antiferromagnetic ... More
YbRh2Si2: Quantum tricritical behavior in itinerant electron systemsOct 17 2007Apr 24 2008We propose that proximity of the first-order transition manifested by the quantum tricritical point (QTCP) explains non-Fermi-liquid properties of YbRh2Si2. Here, at the QTCP, a continuous phase transition changes into first order at zero temperature. ... More
"Visible" 5d orbital states in a pleochroic oxychlorideApr 12 2019Transition metal compounds sometimes exhibit beautiful colors. We report here on a new oxychloride Ca3ReO5Cl2 which shows unusually distinct pleochroism; that is, the material exhibits different colors depending on viewing directions. This ple-ochroism ... More
Effective Hamiltonian for cuprate superconductors derived from multi-scale ab initio scheme with level renormalizationJan 02 2019Three-types (three-band, two-band and one-band) of effective Hamiltonians for the HgBa$_2$CuO$_4$ and three-band effective Hamiltonian for La$_2$CuO$_4$ are derived beyond the level of the constrained-GW approximation combined with the self-interaction ... More
Ab initio Studies of Magnetism in the Iron Chalcogenides FeTe and FeSeMay 14 2015Aug 16 2015The iron chalcogenides FeTe and FeSe belong to the family of iron-based superconductors. We study the magnetism in these compounds in the normal state using the ab initio downfolding scheme developed for strongly correlated electron systems. In deriving ... More
Finite-Temperature Variational Monte Carlo Method for Strongly Correlated Electron SystemsOct 19 2015Jan 25 2016A new computational method for finite-temperature properties of strongly correlated electrons is proposed by extending the variational Monte Carlo method originally developed for the ground state. The method is based on the path integral in the imaginary-time ... More
Mott Transition and Phase Diagram of $κ$-(BEDT-TTF)2Cu(NCS)2 Studied by Two-Dimensional Model Derived from Ab initio MethodOct 28 2011Feb 08 2012We present an ab initio analysis for the ground-state properties of a correlated organic compound $\kappa$-(BEDT-TTF)2Cu(NCS)2. First, we derive an effective two-dimensional low-energy model from first principles, having short-ranged transfers and short-ranged ... More
Self-Optimized Superconductivity Attainable by Interlayer Phase Separation at Cuprate InterfacesAug 22 2016Stabilizing superconductivity at high temperatures and elucidating its mechanism have long been major challenges of materials research in condensed matter physics. Meanwhile, recent progress in nanostructuring offers unprecedented possibilities for designing ... More
Frequency Dependence of Polarization of Zebra Pattern in Type-IV Solar Radio BurstsAug 11 2015We investigated the polarization characteristics of a zebra pattern (ZP) in a type-IV solar radio burst observed with AMATERAS on 2011 June 21 for the purpose of evaluating the generation processes of ZP. Analyzing highly resolved spectral and polarization ... More
3D Dirac Electrons on a Cubic Lattice with Noncoplanar Multiple-Q OrderMay 22 2013Feb 04 2014Noncollinear and noncoplanar spin textures in solids manifest themselves not only in their peculiar magnetism but also in unusual electronic and transport properties. We here report our theoretical studies of a noncoplanar order on a simple cubic lattice ... More
Electromagnetic spin polarization on the surface of topological insulatorAug 08 2011We study the spin polarization of the electrons on the surface of topological insulators under a dc electric field or a circularly polarized light by using Keldysh Green's function formalism. When a dc electric field $E_x \sim 10^{3} {\rm V/m}$ is applied, ... More
Heat conduction in the diatomic Toda lattice revisitedNov 28 1998The problem of the diverging thermal conductivity in one-dimensional (1-D) lattices is considered. By numerical simulations, it is confirmed that the thermal conductivity of the diatomic Toda lattice diverges, which is opposite to what one has believed ... More
Rheology and dynamical heterogeneity in frictionless beads at jamming densityApr 03 2008Dec 20 2015We investigate the rheological properties of an assembly of inelastic (but frictionless) particles close to the jamming density using numerical simulation, in which uniform steady states with a constant shear rate $\dot\gamma$ is realized. The system ... More
Power-law friction in closely-packed granular materialsDec 14 2006May 08 2007In order to understand the nature of friction in closely-packed granular materials, a discrete element simulation on granular layers subjected to isobaric plain shear is performed. It is found that the friction coefficient increases as the power of the ... More
Dynamics of a dislocation bypassing an impenetrable precipitate: the Hirsch mechanism revisitedNov 15 2005May 08 2006Dynamical process where an edge dislocation in fcc copper bypasses an impenetrable precipitate is investigated by means of molecular dynamics simulation. A mechanism which is quite different from the Orowan mechanism is observed, where a dislocation leaves ... More
Homotopy types of Hom complexes of graphsSep 13 2015Apr 19 2016The Hom complex ${\rm Hom}(T,G)$ of graphs is a CW-complex associated to a pair of graphs $T$ and $G$. It is known that certain homotopy invariants of ${\rm Hom}(T,G)$ sometimes give lower bounds for the chromatic number of $G$. On the other hand, we ... More
Morphism complexes of sets with relationsFeb 03 2014Apr 19 2016Let $r$ be a positive integer. An $r$-set is a pair $X= (V(X),R(X))$ consisting of a set $V(X)$ with a subset $R(X)$ of the direct product $V(X)^r$. The object of this paper is to investigate the Hom complexes of $r$-sets, which were introduced for graphs ... More
Answers of some problems about graph coloring test graphsMar 06 2013We give answers of two problems about graph coloring test graphs suggested by Kozlov. We prove that a graph whose chromatic number is 2 is a homotopy test graph. We prove there is a graph $T$ with two involutions $\gamma_1$ and $\gamma_2$ where $(T,\gamma_1)$ ... More
Extinction Map of the Galactic center: OGLE-II Galactic bulge fieldsSep 06 2003Dec 01 2003We present the reddening (E(V-I)) and Extinction maps in V-band (A_V) and I-band (A_I) for 48 Optical Gravitational Lensing Experiment II (OGLE-II) Galactic bulge (GB) fields, covering a range of $-11^\circ <l< 11^\circ$, with the total area close to ... More
Higher-dimensional contact manifolds with infinitely many Stein fillingsAug 04 2016Nov 17 2016For any integer $n\geq 2$, we construct an infinite family of Stein fillable contact $(4n-1)$-manifolds each of which admits infinitely many pairwise homotopy inequivalent Stein fillings.
Recent Results on High-Q2 Neutral and Charged Current Cross Sections at HERAJun 07 2001High-Q^2 NC and CC DIS cross sections have been measured by H1 and ZEUS at HERA. Both NC and CC results based on data taken during the year 1994-2000 are in good agreement with Standard Model expectations. The structure function xF_3 is extracted from ... More
Wall-crossing, Toric divisor and Seiberg dualityApr 30 2013We study the wall-crossing phenomena of BPS D4-D2-D0 states on the conifold and orbifold C^2/Z_2, from the viewpoint of the quiver quantum mechanics on the D-branes. The Kahler moduli dependence of the BPS index is translated into the FI parameter dependence ... More
On non-abelian Lubin-Tate theory for GL(2) in the odd equal characteristic caseApr 29 2016In this paper, we define a family of affinoids in the tubular neighborhoods of CM points in the Lubin-Tate curve with suitable level structures, and compute the reductions of them in the equal characteristic case. By using etale cohomology theory of adic ... More
$L^2$ estimates and vanishing theorems for holomorphic vector bundles equipped with singular Hermitian metricsFeb 28 2018We investigate singular Hermitian metrics on vector bundles, especially strictly Griffiths positive ones. $L^2$ esitimates and vanishing theorems usually require an assumption that vector bundles are Nakano positive. However there is no general definition ... More
A comment on trans-Planckian physics in inflationary universeDec 20 2000Feb 21 2001There are several works searching for a clue of trans-Planckian physics on the primordial density perturbation spectrum. Here we would like to point out an important aspect which has been overlooked so far. When we consider a model in which the primordial ... More
Coribbon Hopf (face) algebras generated by lattice modelsApr 16 1999By studying ``points of the underlying quantum groups''of coquasitriangular Hopf (face) algebras, we construct ribbon categories for each lattice models without spectral parameter of both vertex and face type. Also, we give a classification of the braiding ... More
Zon-Cohen singularity and negative inverse temperature in a trapped particle limitMay 09 2012Jun 22 2012We study a Brownian particle on a moving periodic potential. We focus on the statistical properties of the work done by the potential and the heat dissipated by the particle. When the period and the depth of the potential are both large, by using a boundary ... More
Ample canonical heights for endomorphisms on projective varietiesOct 15 2017Feb 02 2018We define an "ample canonical height" for an endomorphism on a projective variety, which is essentially a generalization of the canonical heights for polarized endomorphisms introduced by Call--Silverman. We formulate a dynamical analogue of the Northcott ... More
Symmetry of Reidemeister torsion on $SU_2$-representation spaces of knotsJan 24 2008Sep 17 2009We study two sorts of actions on the space of conjugacy classes of irreducible $SU_2$-representations of a knot group. One of them is an involution which comes from the algebraic structure of $SU_2$ and the other is the action by the outer automorphism ... More
Fourier and Cauchy-Stieltjes transforms of power laws including stable distributionsJul 20 2011Oct 16 2011We introduce a class of probability measures whose densities near infinity are mixtures of Pareto distributions. This class can be characterized by the Fourier transform which has a power series expansion including real powers, not only integer powers. ... More
Rate and state friction law as derived from atomistic processes at asperitiesDec 16 2015A theoretical account is given of the microscopic basis of the rate- and state-dependent friction (RSF) law. The RSF law describes rock friction quantitatively and therefore it is commonly used to model earthquakes and the related phenomena. But the RSF ... More
Scaling of the critical slip distance in granular layersJun 20 2009We investigate the nature of friction in granular layers by means of numerical simulation focusing on the critical slip distance, over which the system relaxes to a new stationary state. Analyzing a transient process in which the sliding velocity is instantaneously ... More
On localizations of the characteristic classes of l-adic sheaves and conductor formula in characteristic p>0May 12 2009The Grothendieck-Ogg-Shafarevich formula calculates the l-adic Euler-Poincare number of an l-adic sheaf on a curve by an invariant produced by the wild ramification of the l-adic sheaf named Swan class. A. Abbes, K. Kato and T. Saito generalize this formula ... More
Box complexes and homotopy theory of graphsMay 20 2016We introduce a model structure on the category of graphs, and showed that it is Quillen equivalent to the category of $\mathbb{Z}_2$-spaces. A weak equivalence of the model structure is a graph homomorphism which induces a $\mathbb{Z}_2$-homotopy equivalence ... More
Some examples of non-tidy spacesApr 23 2014Apr 26 2014We construct a free $\mathbb{Z}_2$-manifold $X_n$ for a positive integer $n$ such that $w_1(X_n)^n \neq 0$, but there is no $\mathbb{Z}_2$-equivariant map from $S^2$ to $X_n$.
Box complex and Kronecker double coveringApr 06 2014Sep 13 2015The box complex $B(G)$ is a $\mathbb{Z}_2$-poset associated with a graph $G$, which was introduced in the context of the graph coloring problem. We study the poset structure of box complex. Our main theorem states that, up to isolated vertices, the $\Z_2$-poset ... More
Fundamental groups of neighborhood complexesOct 10 2012Sep 13 2015We introduce the notions of $r$-neighborhood complexes, $r$-fundamental groups and $r$-covering maps of graphs, for a positive integer $r$. The $r$-neighborhood complex $N_r(G)$ is a natural generalization of the neighborhood complex introduced by Lov\'asz. ... More
Supremum of the function $S_1(t)$ on short intervalsJan 01 2013Nov 18 2013We prove a lower bound on the supremum of the function $S_1(T)$ on short intervals, defined by the integration of the argument of the Riemann zeta-function. The same type of result on the supremum of $S(T)$ have already been obtained by Karatsuba and ... More
Multiple D4-D2-D0 on the Conifold and Wall-crossing with the FlopOct 28 2010Dec 22 2010We study the wall-crossing phenomena of D4-D2-D0 bound states with two units of D4-brane charge on the resolved conifold. We identify the walls of marginal stability and evaluate the discrete changes of the BPS indices by using the Kontsevich-Soibelman ... More
Macroscopic Expression Connecting the Rate of Energy Dissipation and Violation of the Fluctuation-Response RelationNov 03 2008Feb 14 2009A direct connection between the magnitude of the violation of the fluctuation-response relation (FRR) and the rate of energy dissipation is presented in terms of field variables of nonequilibrium systems. Here, we consider the density field of a colloidal ... More
AdS/CFT correspondence in a Friedmann-Lemaitre-Robertson-Walker braneFeb 15 2004Aug 30 2004According to the AdS/CFT correspondence conjecture, the Randall-Sundrum infinite braneworld is equivalent to four dimensional Einstein gravity with ${\cal N}=4$ super Yang-Mills fields at low energies. Here we derive a four dimensional effective equation ... More
Compact Stein surfaces as branched covers with same branch setsAug 05 2015Jan 21 2016Loi and Piergallini showed that a smooth compact, connected $4$-manifold $X$ with boundary admits a Stein structure if and only if $X$ is a simple branched cover of a $4$-disk $D^4$ branched along a positive braided surface $S$ in a bidisk $D_{1}^{2} ... More
Twisted Alexander polynomials and incompressible surfaces given by ideal pointsDec 15 2014We study incompressible surfaces constructed by Culler-Shalen theory in the context of twisted Alexander polynomials. For a $1$st cohomology class of a $3$-manifold the coefficients of twisted Alexander polynomials induce regular functions on the $SL_2(\mathbb{C})$-character ... More
White noise analysis on manifolds and the energy representation of a gauge groupMay 09 2008Jan 15 2011The energy representation of a gauge group on a Riemannian manifold has been discussed by several authors. Y. Shimada has shown the irreducibility for compact Riemannian manifold, using white noise analysis. In this paper we extend its technique to noncompact ... More
Free infinite divisibility for beta distributions and related onesMay 04 2013Sep 18 2014We prove that many of beta, beta prime, gamma, inverse gamma, Student t- and ultraspherical distributions are freely infinitely divisible, but some of them are not. The latter negative result follows from a local property of probability density functions. ... More
Spatiotemporal Behavior of Void Collapse in Shocked SolidsJun 25 2003Sep 08 2003Molecular dynamics simulations on a three dimensional defective Lennard-Jones solid containing a void are performed in order to investigate detailed properties of hot spot generation. In addition to the temperature, I monitor the number of energetically ... More
Deformations of box complexesDec 11 2013Jun 28 2015Box complex is a $\mathbb{Z}_2$-space associated to a graph, and it is known that a certain $\mathbb{Z}_2$-homotopy invariant of it, called the $\mathbb{Z}_2$-index, gives an effective lower bound for the chromatic number. On the other hand, we show that ... More
$r$-fundamental groups of graphsJan 30 2013Sep 13 2015In this paper, we introduce the notions of $r$-fundamental groups of graphs, $r$-covering maps, and $r$-neighborhood complexes of graphs for a positive integer $r$. There is a natural correspondence between $r$-covering maps and $r$-fundamental groups ... More
The gravity duals of SO/USp superconformal quiversFeb 29 2012Apr 19 2012We study the gravity duals of SO/USp superconformal quiver gauge theories realized by M5-branes wrapping on a Riemann surface ("G-curve") together with a Z_2-quotient. When the G-curve has no punctures, the gravity solutions are classified by the genus ... More
Calogero-Moser hierarchy and KP hierarchyFeb 03 1994The space of solutions of the rational Calogero-Moser hierarchy, and the space of solutions of the KP hierarchy whose tau functions are monic polynomials in $t_1$ with coefficients depending on $t_n$, $n > 1$, are identified, generalizing earlier results ... More
Loop space construction of bigraphs and box complexesOct 19 2016Dochtermann introduced the loop space construction of a based graph $(G,v)$ whose basepoint is a looped vertex. He showed that the complex $C(\Omega(G,v))$ is homotopy equivalent to the loop space $\Omega(C(G),v)$ of $C(G)$. Here we write $C(G)$ to mean ... More
On prolongations of second-order regular overdetermined systems with two independent and one dependent variablesOct 18 2012The purpose of this present paper is to investigate the geometric structure of regular overdetermined systems of second order with two independent and one dependent variables from the point of view of rank 2 prolongations. Utilizing this notion of prolongations, ... More
Specific heat of the ideal gas obeying the generalized exclusion statisticsMay 20 2000Feb 02 2001We calculate the specific heat of the ideal gas obeying the generalized exclusion statistics (GES) in the continuum model and the tight binding model numerically. In the continuum model of 3-d space, the specific heat increases with statistical parameter ... More
Weak gravity in DGP braneworld modelMay 08 2003May 12 2003We analyze the weak gravity in the braneworld model proposed by Dvali-Gabadadze-Porrati, in which the unperturbed background spacetime is given by five dimensional Minkowski bulk with a brane which has the induced Einstein Hilbert term. This model has ... More
Classical black hole evaporation in Randall-Sundrum infinite braneworldMar 24 2002Apr 03 2002After the gravity induced on the brane in the Randall-Sundrum (RS) infinite braneworld is briefly reviewed, we discuss the possibility that black holes evaporate as a result of classical evolution in this model based on the AdS/CFT correspondence. If ... More
The No-Negative Mode Theorem in False Vacuum Decay with GravityJan 28 1999Feb 23 1999The so-called negative mode problem in the path integral approach to the false vacuum decay with the effect of gravity has been an unsolved problem. Several years ago, we proposed a conjecture which is to be proved in order to give a consistent solution ... More
Face algebras and unitarity of SU(N)_L-TQFTApr 16 1999Using face algebras (i.e. algebras of L-operators of IRF models), we construct modular tensor categories with positive definite inner product, whose fusion rules and S-matrices are the same as (or slightly different from) those obtained by $U_q (\frak{sl}_{N})$ ... More
Conditionally monotone independence II: Multiplicative convolutions and infinite divisibilityOct 07 2009Mar 26 2011We study the multiplicative convolution for c-monotone independence. This convolution unifies the monotone, Boolean and orthogonal multiplicative convolutions. We characterize convolution semigroups for the c-monotone multiplicative convolution on the ... More
Conditionally monotone independence I: Independence, additive convolutions and related convolutionsJul 31 2009Mar 26 2011We define a product of algebraic probability spaces equipped with two states. This product is called a conditionally monotone product. This product is a new example of independence in non-commutative probability theory and unifies the monotone and Boolean ... More
Analytic continuations of Fourier and Stieltjes transforms and generalized moments of probability measuresSep 08 2010Jan 15 2011We consider analytic continuations of Fourier transforms and Stieltjes transforms. This enables us to define what we call complex moments for some class of probability measures which do not have moments in the usual sense. There are two ways to generalize ... More
Hilbertian matrix cross normed spaces arising from normed idealsJul 31 2006Jan 14 2007Generalizing Pisier's idea, we introduce a Hilbertian matrix cross normed space associated with a pair of symmetric normed ideals. When the two ideals coincide, we show that our construction gives an operator space if and only if the ideal is the Schatten ... More
New associative product of three states generalizing free, monotone, anti-monotone, Boolean, conditionally free and conditionally monotone productsSep 08 2010We define a new independence in three states called indented independence which unifies many independences: free, monotone, anti-monotone, Boolean, conditionally free, conditionally monotone and conditionally anti-monotone independences. This unification ... More
Equivalence Problem for Second Order Partially Differential Equations and Double Fibration as a Flat Model SpaceMar 26 2007In this paper, we consider an equivalence problem of second order partially differential equations (PDE) and a duality of the flat differential equation. For the equivalence problem, explicit form of invariants (curvatures) are given. We also investigate ... More
Non-commutative Reidemeister torsion and Morse-Novikov theoryJun 23 2009Jul 07 2010Given a circle-valued Morse function of a closed oriented manifold, we prove that Reidemeister torsion over a non-commutative formal Laurent polynomial ring equals the product of a certain non-commutative Lefschetz-type zeta function and the algebraic ... More
Free infinite divisibility for powers of random variablesSep 29 2015Mar 10 2016We prove that $X^r$ follows a free regular distribution, i.e. the law of a nonnegative free L\'evy process if: (1) $X$ follows a free Poisson distribution without an atom at 0 and $r\in(-\infty,0]\cup[1,\infty)$; (2) $X$ follows a free Poisson distribution ... More
Normalization of twisted Alexander invariantsMay 16 2007Jul 05 2015Twisted Alexander invariants of knots are well-defined up to multiplication of units. We get rid of this multiplicative ambiguity via a combinatorial method and define normalized twisted Alexander invariants. We then show that the invariants coincide ... More
Obstruction of $C_\infty$-algebra models and characteristic classesSep 02 2018In this paper, we consider an obstruction-theoretical construction of characteristic classes of fiber bundles by simplicial method. We can get a certain obstruction class for a deformation of $C_\infty$-algebra models of fibers and a characteristic map ... More
Jordan Matsuo algebras over fields of characteristic 3Aug 07 2017The Matsuo algebra associated with a connected Fischer space is shown to be a Jordan algebra over a field of characteristic 3 if and only if the Fischer space is isomorphic to either the affine space of order 3 or the Fischer space associated with the ... More
On localizations of characteristic classes of l-adic sheaves of rank 1May 13 2009The Grothendieck-Ogg-Shafarevich formula is generalized to any dimensional scheme by Abbes-Kato-Saito. In this paper, we introduce two methods of localization of the characteristic classes for sheaves of rank 1 and compare them. As a corollary of this ... More
Radiative Corrections to Low-Energy Neutrino-Deuteron Reactions RevisitedJan 11 2006Jan 20 2006The one-loop QED and electroweak radiative corrections to neutrino-deuteron scattering induced by the neutral current are reexamined, paying a particular attention to the constant term which has never been treated properly in literature. This problem ... More
Friction laws from dimensional-analysis point of viewAug 20 2015Friction laws, which are a key to the understanding of the diversity of earthquakes, are considered theoretically. Using dimensional analysis, the logarithmic dependence of the friction coefficient on the slip velocity and the state variable is derived ... More
Jarzynski equality for the transitions between nonequilibrium steady statesMay 03 1999Jul 28 1999Jarzynski equality [Phys. Rev. E {\bf 56}, 5018 (1997)] is found to be valid with slight modefication for the transitions between nonequilibrium stationary states, as well as the one between equilibrium states. Also numerical results confirm its validity. ... More
Generalization of neighborhood complexesMay 11 2013We introduce the notion of r-neighborhood complex for a positive integer r, which is a natural generalization of Lovasz neighborhood complex. The topologies of these complexes give some obstructions of the existence of graph maps. We applied these complexes ... More
An explicit upper bound of the argument of Dirichlet $L$-functions on the generalized Riemann hypothesisJun 11 2014Jul 25 2014We prove an explicit upper bound of the function $S(t,\chi)$, defined by the argument of Dirichlet $L$-functions. An explicit upper bound of the function $S_1(t)$, defined by the integral of the argument of the Riemann zeta-function, have already been ... More
Asymptotic Behavior of Perturbations in Randall-Sundrum Brane-WorldJun 06 2000The asymptotic behavior of metric perturbations in Randall-Sundrum infinite brane world is carefully investigated. Perturbations generated by matter fields on the brane are shown to be regular even at the future Cauchy horizon.
Implication of Classical Black Hole Evaporation Conjecture to Floating Black HolesSep 23 2007Mar 13 2009In Randall-Sundrum single-brane (RS-II) model, it was conjectured that there is no static large black hole localized on the brane based on adS/CFT correspondence. Here we consider the phase diagram of black objects in the models extended from the RS-II ... More
Gravitational radiation reactionAug 28 2005Oct 04 2005We give a short personally-biased review on the recent progress in our understanding of gravitational radiation reaction acting on a point particle orbiting a black hole. The main motivation of this study is to obtain sufficiently precise gravitational ... More
Stein fillings of homology $3$-spheres and mapping class groupsJul 20 2014In this article, using combinatorial techniques of mapping class groups, we show that a Stein fillable integral homology $3$-sphere supported by an open book decomposition with page a $4$-holed sphere admits a unique Stein filling up to diffeomorphism. ... More
On generic vanishing for pluricanonical bundlesJul 12 2015Jan 29 2016We study cohomology support loci and higher direct images of (log) pluricanonical bundles of smooth projective varieties or log canonical pairs. We prove that the 0-th cohomology support loci of log pluricanonical bundles are finite unions of torsion ... More
A canonical Tannaka duality for finite seimisimple tensor categoriesApr 15 1999Apr 16 1999For each finite semisimple tensor category, we associate a quantum group (face algebra) whose comodule category is equivalent to the original one, in a simple natural manner. To do this, we also give a generalization of the Tannaka-Krein duality, which ... More
Growing length and time scales in a suspension of athermal particlesJul 23 2008Feb 03 2009We simulate a relaxation process of non-brownian particles in a sheared viscous medium; the small shear strain is initially applied to a system, which then undergoes relaxation. The relaxation time and the correlation length are estimated as functions ... More
Scaling properties of granular rheology near the jamming transitionMar 15 2008Nov 02 2008Rheological properties of a dense granular material consisting of frictionless spheres are investigated. It is found that the shear stress, the pressure, and the kinetic temperature obey critical scaling near the jamming transition point, which is considered ... More
Dislocation nucleation in shocked fcc solids: effects of temperature and preexisting voidsJan 14 2004Mar 01 2005Quantitative behaviors of shock-induced dislocation nucleation are investigated by means of molecular dynamics simulations on fcc Lennard-Jones solids: a model Argon. In perfect crystals, it is found that Hugoniot elastic limit (HEL) is a linearly decreasing ... More