Results for "Masahiro Takeoka"

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Discrimination of binary coherent states using a homodyne detector and a photon number resolving detectorFeb 01 2010We investigate quantum measurement strategies capable of discriminating two coherent states probabilistically with significantly smaller error probabilities than can be obtained using non- probabilistic state discrimination. We apply a postselection strategy ... More
Lorentz invariant entanglement distribution for the space-based quantum networkApr 16 2017In recent years there has been a great deal of focus on a globe-spanning quantum network, including linked satellites for applications ranging from quantum key distribution to distributed sensors and clocks. In many of these schemes, relativistic transformations ... More
Classical simulation of boson sampling with sparse outputApr 11 2019Boson sampling can simulate physical problems for which classical simulations are inefficient. However, not all problems simulated by boson sampling are classically intractable. We consider a situation in which it is known that the outcome from boson ... More
Capacity of optical communication in loss and noise with general Gaussian receiversJan 21 2014Apr 11 2014Laser-light (coherent-state) modulation is sufficient to achieve the ultimate (Holevo) capacity of classical communication over a lossy and noisy optical channel, but requires a receiver that jointly detects long modulated codewords with highly nonlinear ... More
Conditional generation of an arbitrary superposition of coherent statesFeb 13 2007We present a scheme to conditionally generate an arbitrary superposition of a pair of coherent states from a squeezed vacuum by means of the modified photon subtraction where a coherent state ancilla and two on/off type detectors are used. We show that, ... More
Discrimination of the binary coherent signal: Gaussian-operation limit and simple non-Gaussian near-optimal receiversJun 07 2007Aug 14 2008We address the limit of the Gaussian operations and classical communication in the problem of quantum state discrimination. We show that the optimal Gaussian strategy for the discrimination of the binary phase shift keyed (BPSK) coherent signal is a simple ... More
Optimal estimation and discrimination of excess noise in thermal and amplifier channelsNov 28 2016We determine a fundamental upper bound on the performance of any adaptive protocol for discrimination or estimation of a channel which has an unknown parameter encoded in the state of its environment. Since our approach relies on the principle of data ... More
Inter-Core Crosstalk Impact of Classical Channels on CV-QKD in Multicore Fiber TransmissionJan 11 2019Crosstalk-induced excess noise is experimentally characterized for continuous-variable quantum key distribution, spatially multiplexed with WDM PM-16QAM channels in a 19-core fiber. The measured noise-sources are used to estimate the secret key rates ... More
Experimental transmission of quantum digital signatures over 90-km of installed optical fiber using a differential phase shift quantum key distribution systemAug 15 2016Quantum digital signatures apply quantum mechanics to the problem of guaranteeing message integrity and non-repudiation with information-theoretical security, which are complementary to the confidentiality realized by quantum key distribution. Previous ... More
Unambiguous quantum state filteringApr 04 2003In this paper, we consider the generalized measurement where one particular quantum signal is unambiguously extracted from a set of non-commutative quantum signals and the other signals are filtered out. Simple expressions for the maximum detection probability ... More
Practical scheme for the optimal measuremnet in quantum interferometric devicesDec 06 2002Mar 26 2003We apply a Kennedy-type detection scheme, which was originally proposed for a binary communications system, to interferometric sensing devices. We show that the minimum detectable perturbation of the proposed system reaches the ultimate precision bound ... More
Temporally multiplexed superposition states of continuous variablesApr 02 2008Apr 08 2008We study non-Gaussian states generated by two-photon subtraction from a cw squeezed light source. In a cw scheme one can subtract two photons from the source with a designated time separation and can genarate temporally multiplexed superposition states ... More
Invariance of the bit error rate in the ancilla-assisted homodyne detectionMar 22 2010We investigated the minimum achievable bit error rate of discriminating binary coherent states by homodyne measurements with the help of arbitrary ancilla states coupled via beam splitters. We took into account arbitrary pure ancillary states those were ... More
Towards practical device-independent quantum key distribution with spontaneous parametric downconversion sources, on-off photodetectors and entanglement swappingDec 21 2015Jan 13 2016Device-independent quantum key distribution (DIQKD) guarantees unconditional security of secret key without making assumptions about the internal workings of the devices used. It does so using the loophole-free violation of a Bell's inequality. The primary ... More
Quantum channel of continuous variable teleportation and nonclassicality of quantum statesOct 05 2001Noisy teleportation of nonclassical quantum states via a two-mode squeezed-vacuum state is studied with the completely positive map and the Glauber-Sudarshan $P$-function. Using the nonclassical depth as a measure of transmission performance, we compare ... More
Fundamental rate-loss tradeoff for optical quantum key distributionApr 24 2015Since 1984, various optical quantum key distribution (QKD) protocols have been proposed and examined. In all of them, the rate of secret key generation decays exponentially with distance. A natural and fundamental question is then whether there are yet-to-be ... More
The squashed entanglement of a quantum channelOct 01 2013Jan 21 2014This paper defines the squashed entanglement of a quantum channel as the maximum squashed entanglement that can be registered by a sender and receiver at the input and output of a quantum channel, respectively. A new subadditivity inequality for the original ... More
Full analysis of multi-photon pair effects in spontaneous parametric down conversion based photonic quantum information processingOct 14 2014May 07 2015In spontaneous parametric down conversion (SPDC) based quantum information processing (QIP) experiments, there is a tradeoff between the coincide count rates (i.e. the pumping power of the SPDC), which limits the rate of the protocol, and the visibility ... More
Continuous variable teleportation as a generalized thermalizing quantum channelFeb 28 2002A quantum channel is derived for continuous variable teleportation which is performed by means of an arbitrary entangled state and the standard protocol. When a Gaussian entangled state such as a two-mode squeezed-vacuum state is used, the continuous ... More
Binary projective measurement via linear optics and photon countingMar 09 2006Mar 19 2006We investigate the implementation of binary projective measurements with linear optics. This problem can be viewed as a single-shot discrimination of two orthogonal pure quantum states. We show that any two orthogonal states can be perfectly discriminated ... More
Large amplitude coherent state superposition generated by a time-separated two-photon subtraction from a continuous wave squeezed vacuumApr 03 2008Jun 18 2008Theoretical analysis is given for a two-photon subtraction from a continuous wave (CW) squeezed vacuum with finite time separation between two detection events. In the CW photon subtraction process, the generated states are inevitably described by temporal ... More
PPM demodulation: On approaching fundamental limits of optical communicationsJan 14 2010May 08 2010We consider the problem of demodulating M-ary optical PPM (pulse-position modulation) waveforms, and propose a structured receiver whose mean probability of symbol error is smaller than all known receivers, and approaches the quantum limit. The receiver ... More
Heralded amplification of nonlocality via entanglement swapping for long-distance device-independent quantum key distributionApr 12 2019To realize the practical implementation of device-independent quantum key distribution~(DIQKD), the main difficulty is that its security relies on the detection-loophole-free violation of the Clauser-Horne-Shimony-Holt~(CHSH) inequality, i.e. the CHSH ... More
Entanglement evaluation of non-Gaussian states generated by photon subtraction from squeezed statesDec 09 2005Feb 22 2006We consider the problem of evaluating the entanglement of non-Gaussian mixed states generated by photon subtraction from entangled squeezed states. The entanglement measures we use are the negativity and the logarithmic negativity. These measures possess ... More
Unambiguous discrimination among oracle operatorsFeb 26 2007Jul 08 2007We address the problem of unambiguous discrimination among oracle operators. The general theory of unambiguous discrimination among unitary operators is extended with this application in mind. We prove that entanglement with an ancilla cannot assist any ... More
Entanglement quantification with Fisher informationDec 13 2006We show that the Fisher information associated with entanglement-assisted coding has a monotonic relationship with the logarithmic negativity, an important entanglement measure, for certain classes of continuous variable (CV) quantum states of practical ... More
Bounds on entanglement distillation and secret key agreement for quantum broadcast channelsMar 27 2015Mar 18 2016The squashed entanglement of a quantum channel is an additive function of quantum channels, which finds application as an upper bound on the rate at which secret key and entanglement can be generated when using a quantum channel a large number of times ... More
Implementation of projective measurements with linear optics and continuous photon countingOct 18 2004Mar 04 2005We investigate the possibility of implementing a given projection measurement using linear optics and arbitrarily fast feedforward based on the continuous detection of photons. In particular, we systematically derive the so-called Dolinar scheme that ... More
Quantum receivers with squeezing and photon-number-resolving detectorsFeb 12 2013Apr 16 2013We propose quantum receivers with optical squeezing and photon-number-resolving detector (PNRD) for the near-optimal discrimination of quaternary phase-shift-keyed coherent state signals. The basic scheme is similar to the previous proposals (e.g. Phys. ... More
Exceeding classical capacity limit in quantum optical channelApr 04 2003The amount of information transmissible through a communications channel is determined by the noise characteristics of the channel and by the quantities of available transmission resources. In classical information theory, the amount of transmissible ... More
Wavelength division multiplexed and double-port pumped time-bin entangled photon pair generation using Si ring resonatorFeb 09 2017We report a wavelength division multiplexed time-bin entangled photon pair source in telecom wavelength using a 10 {\mu}m radius Si ring resonator. This compact resonator has two add ports and two drop ports. By pumping one add port by a continuous laser, ... More
Effective squeezing enhancement via measurement-induced non-Gaussian operation and its application to dense coding schemeMar 04 2005May 18 2005We study the measurement-induced non-Gaussian operation on the single- and two-mode \textit{Gaussian} squeezed vacuum states with beam splitters and on-off type photon detectors, with which \textit{mixed non-Gaussian} states are generally obtained in ... More
Unconstrained distillation capacities of a pure-loss bosonic broadcast channelJan 21 2016Apr 07 2016Bosonic channels are important in practice as they form a simple model for free-space or fiber-optic communication. Here we consider a single-sender two-receiver pure-loss bosonic broadcast channel and determine the unconstrained capacity region for the ... More
Bounding the energy-constrained quantum and private capacities of phase-insensitive bosonic Gaussian channelsAug 24 2017Jun 15 2018We establish several upper bounds on the energy-constrained quantum and private capacities of all single-mode phase-insensitive bosonic Gaussian channels. The first upper bound, which we call the "data-processing bound," is the simplest and is obtained ... More
Quantum receiver beyond the standard quantum limit of coherent optical communicationMar 29 2011The most efficient modern optical communication is known as coherent communication and its standard quantum limit (SQL) is almost reachable with current technology. Though it has been predicted for a long time that this SQL could be overcome via quantum ... More
Sub-shot-noise-limit discrimination of on-off keyed coherent signals via a quantum receiver with a superconducting transition edge sensorFeb 15 2010We demonstrate a sub-shot-noise-limit discrimination of on-off keyed coherent signals by an optimal displacement quantum receiver in which a superconducting transition edge sensor is installed. Use of a transition edge sensor and a fiber beam splitter ... More
Highly efficient entanglement swapping and teleportation at telecom wavelengthOct 01 2014Entanglement swapping at telecom wavelengths is at the heart of quantum networking in optical fiber infrastructures. Although entanglement swapping has been demonstrated experimentally so far using various types of entangled photon sources both in near-infrared ... More
Displacement receiver for phase-shift-keyed coherent statesAug 09 2012Quantum receiver is an important tool for overcoming the standard quantum limit (SQL) of discrimination errors in optical communication. We theoretically study the quantum receivers for discriminating ternary and quaternary phase shift keyed coherent ... More
Optical phase estimation via coherent state and displaced photon countingApr 15 2016Jun 21 2016We consider the phase sensing via weak optical coherent state at quantum limit precision. A new detection scheme for the phase estimation is proposed which is inspired by the suboptimal quantum measurement in coherent optical communication. We theoretically ... More
Conclusive Precision Bounds for SU(1,1) InterferometersOct 18 2018In this paper, we revisit the quantum Fisher information (QFI) calculation in SU(1,1) interferometer considering different phase configurations. When one of the input modes is a vacuum state, we show by using phase averaging, different phase configurations ... More
Generation of large-amplitude coherent-state superposition via ancilla-assisted photon-subtractionJun 18 2008Dec 05 2008We propose and demonstrate a novel method to generate a large-amplitude coherent-state superposition (CSS) via ancilla-assisted photon-subtraction. The ancillary mode induces quantum interference of indistinguishable processes, widening the controllability ... More
Optimal conditions for Bell test using spontaneous parametric down-conversion sourcesAug 25 2018We theoretically and experimentally investigate the optimal conditions for the Bell experiment using spontaneous parametric down conversion (SPDC) sources. In theory, we show that relatively large average photon number (typically $\sim$0.5) is desirable ... More
Non-Gaussian entanglement distillation for continuous variablesJul 13 2009Entanglement distillation is an essential ingredient for long distance quantum communications. In the continuous variable setting, Gaussian states play major roles in quantum teleportation, quantum cloning and quantum cryptography. However, entanglement ... More
Fundamental precision limit of a Mach-Zehnder interferometric sensor when one of the inputs is the vacuumMay 26 2017In the lore of quantum metrology, one often hears (or reads) the following no-go theorem: If you put vacuum into one input port of a balanced Mach-Zehnder Interferometer, then no matter what you put into the other input port, and no matter what your detection ... More
Optical continuous-variable qubitFeb 17 2010In a new branch of quantum computing, information is encoded into coherent states, the primary carriers of optical communication. To exploit it, quantum bits of these coherent states are needed, but it is notoriously hard to make superpositions of such ... More
Practical purification scheme for decohered coherent-state superpositions via partial homodyne detectionOct 31 2005Aug 02 2006We present a simple protocol to purify a coherent-state superposition that has undergone a linear lossy channel. The scheme constitutes only a single beam splitter and a homodyne detector, and thus is experimentally feasible. In practice, a superposition ... More
Photon subtraction from traveling fields - recent experimental demonstrationsApr 21 2011We review our most recent results on application of the photon subtraction technique for optical quantum information processing primitives, in particular entanglement distillation and generation of squeezed qubit states. As an introduction we provide ... More
Projective measurement onto arbitrary superposition of coherent state basesFeb 21 2017Feb 15 2018One of the peculiar features in quantum mechanics is that a superposition of macroscopically distinct states can exits. In optical system, this is highlighted by a superposition of coherent states (SCS), i.e. a superposition of classical states. Recently ... More
Demonstration of Coherent State Discrimination Using a Displacement Controlled Photon Number Resolving DetectorJun 16 2009Feb 01 2010We experimentally demonstrate a new measurement scheme for the discrimination of two coherent states. The measurement scheme is based on a displacement operation followed by a photon number resolving detector, and we show that it outperforms the standard ... More
Ultrabroadband direct detection of nonclassical photon statistics at telecom wavelengthAug 08 2013Broadband light sources play essential roles in diverse fields, such as high-capacity optical communications, optical coherence tomography, optical spectroscopy, and spectrograph calibration. Though an ultrabroadband nonclassical state from standard spontaneous ... More
Two-lane traffic-flow model with an exact steady-state solutionSep 07 2010We propose a stochastic cellular-automaton model for two-lane traffic flow based on the misanthrope process in one dimension. The misanthrope process is a stochastic process allowing for an exact steady-state solution; hence we have an exact flow-density ... More
Ground-State Entanglement Bound for Quantum Energy Teleportation of General Spin-Chain ModelsJan 01 2013Feb 28 2013Many-body quantum systems in the ground states have zero-point energy due to the uncertainty relation. In many cases, the system in the ground state accompanies spatially-entangled energy density fluctuation via the noncommutativity of the energy density ... More
Quantum Energy Teleportation with Trapped IonsAug 20 2009Sep 30 2009We analyse a protocol of quantum energy teleportation that transports energy from the left edge of a linear ion crystal to the right edge by local operations and classical communication at a speed considerably greater than the speed of a phonon in the ... More
Wakefield Acceleration by Radiation Pressure in Relativistic Shock WavesSep 12 2007A particle acceleration mechanism by radiation pressure of precursor waves in a relativistic shock is studied. For a relativistic, perpendicular shock with the upstream bulk Lorentz factor of $\gamma_1 \gg 1$, large amplitude electromagnetic (light) waves ... More
Fusion rules and macroscopic loops from discretized approach to two-dimensional gravityMar 13 1997Apr 04 1997We investigate the multi-loop correlators and the multi-point functions for all of the scaling operators in unitary minimal conformal models coupled to two-dimensional gravity from the two-matrix model. We show that simple fusion rules for these scaling ... More
Combined effect of successive competition periods on population dynamicsJul 05 2010This study investigates the effect of competition between individuals on population dynamics when they compete for different resources during different seasons or during different growth stages. Individuals are assumed to compete for a single resource ... More
D0-branes in an H-field Background and Noncommutative GeometryMay 08 1999Sep 10 1999It is known that if we compactify D0-branes on a torus with constant B-field, the resulting theory becomes SYM theory on a noncommutative dual torus. We discuss the extension to the case of a H-field background. In the case of constant H-field on a three-torus, ... More
The Euler number of the Jacobi factor of a plane curve singularity whose semigroup is $\langle4,6,13\rangle$Oct 10 2013Dec 15 2014Piontkowski calculated the Euler number of Jacobi factors of plane curve singularities with semigroups $< p, q>$, $< 4, 2q, s>$, $< 6,8,s>$ and $< 6,10, s>$. %His analysis was done by decomposing the Jacobi factors into affine cells. In this paper, we ... More
The density function for the value-distribution of Lerch zeta-functions and its applicationsMay 28 2018Sep 12 2018The probabilistic study of the value-distribution of zeta-functions is one of the modern topics in analytic number theory. In this paper, we study a probability density function related to the value-distribution of Lerch zeta-functions. We prove a limit ... More
A parametrized generalization of Ohno's relation for multiple zeta valuesAug 18 2009Apr 20 2011In this paper, we prove that certain parametrized multiple series which generalize multiple zeta values satisfy the same relation as Ohno's relation for multiple zeta values. This is a parametrized generalization of Ohno's relation for multiple zeta values. ... More
PL and differential topology in o-minimal structureFeb 08 2010Feb 17 2010Arguments on PL,(=piecewise linear) topology work over any ordered field in the same way as over the real field, and those on differential topology do over a real closed field R in an o-minimal structure that expands (R,<,0,1,+,cdot). One of the most ... More
The polynomial representation of the double affine Hecke algebra of type $(C^\vee_n, C_n)$ for specialized parametersJul 17 2008In this paper, we study the polynomial representation of the double affine Hecke algebra of type $(C^\vee_n, C_n)$ for specialized parameters. Inductively and combinatorially, we give a linear basis of the representation in terms of linear combinations ... More
Quantum enigma machines and the locking capacity of a quantum channelJul 20 2013Nov 09 2013The locking effect is a phenomenon which is unique to quantum information theory and represents one of the strongest separations between the classical and quantum theories of information. The Fawzi-Hayden-Sen (FHS) locking protocol harnesses this effect ... More
A Solution to the Missing Link in the Press-Schechter FormalismAug 29 2001The Press-Schechter (PS) formalism for mass functions of the gravitationally collapsed objects is reanalyzed. It has been suggested by many authors that the PS mass function agrees well with the mass function given by $N$-body simulations, while many ... More
Generation of Alfvénic Waves and Turbulence in Reconnection JetsMay 18 2015The magnetohydrodynamic linear stability with the localized bulk flow oriented parallel to the neutral sheet is investigated, by including the Hall effect and the guide magnetic field. We observe three different unstable modes: a "streaming tearing" mode ... More
Lensing-induced Non-Gaussian Signatures in the Cosmic Microwave BackgroundJan 25 2001Apr 30 2001We propose a new method for extracting the non-Gaussian signatures on the isotemperature statistics in the cosmic microwave background (CMB) sky, which is induced by the gravitational lensing due to the intervening large-scale structure of the universe. ... More
Determination of |V_cb| and Related Results from BABARJun 17 2004The CKM matrix element amplitude |V_cb| was determined using the data collected by the BABAR detector. The partial branching fraction, lepton-energy moments, and hadron-mass moments were measured in inclusive semileptonic decays B -> X_c l nu. A global ... More
An Intuitionistic Set-theoretical Model of the Extended Calculus of ConstructionsDec 06 2014Feb 16 2015Werner's set-theoretical model is one of the most intuitive models of ECC. It combines a functional view of predicative universes with a collapsed view of the impredicative sort Prop. However this model of Prop is so coarse that the principle of excluded ... More
Low-lying magnon excitations in integer-spin ladders and tubesOct 16 2004Sep 17 2005We consider low-energy excitation structures of N-leg integer-spin ladder and tube systems with an antiferromagnetic (AF) intrachain coupling and a uniform external field. The tube means the ladder with the periodic boundary condition along the interchain ... More
Nef vector bundles on a projective space with first Chern class 3 and second Chern class less than 8Apr 20 2016Aug 26 2016We classify nef vector bundles on a projective space with first Chern class three and second Chern class less than eight over an algebraically closed field of characteristic zero; we see, in particular, that, except for one possibly occurring case in ... More
Energy-Entanglement Relation for Quantum Energy TeleportationFeb 01 2010Jun 25 2010Protocols of quantum energy teleportation (QET), while retaining causality and local energy conservation, enable the transportation of energy from a subsystem of a many-body quantum system to a distant subsystem by local operations and classical communication ... More
Asymptotic Isometry and Two Dimensional Anti-de Sitter GravitySep 09 1998We analyze canonical asymptotic isometry of two dimensional AdS dilaton gravity in detail.
On the value-distributions of logarithmic derivatives of Dedekind zeta functionsMay 22 2017Sep 21 2017We study the distributions of values of the logarithmic derivatives of the Dedekind zeta functions on a fixed vertical line. The main object is determining and investigating the density functions of such value-distributions for any algebraic number field. ... More
Semialgebraic metric spcaes and resolution of singularities of definable setsJan 14 2017Aug 30 2017Consider the semialgebraic structure over the real field. More generally, let an ominimal structure be over a real closed field. We show that a definable metric space X with a definable metric d is embedded into a Euclidean space so that its closure is ... More
Classification of generalized polarized manifolds by their nef valuesMar 07 2005Let (M,E) be a generalized polarized manifold, i.e., a pair of an n-dimensional smooth projective variety and an ample vector bundle E of rank r on M. Let t be the nef value of a polarized manifold (M, det E), i.e., the minimum of the set of real numbers ... More
Index of fibrations and Brauer classes that never obstruct the Hasse principleJun 21 2017Jul 04 2017Let $X$ be a smooth projective variety with a fibration into varieties that either satisfy a condition on representability of zero-cycles or that are torsors under an abelian variety. We study the classes in the Brauer group that never obstruct the Hasse ... More
Coexistence of Continuous Variable Quantum Key Distribution and 7 $\times$ 12.5 Gbit/s Classical ChannelsSep 05 2018We study coexistence of CV-QKD and 7 classical 12.5 Gbit/s on-off keying channels in WDM transmission over the C-band. We demonstrate key generation with a distilled secret key rate between 20 to 50 kbit/s in experiments running continuously over 24 hours. ... More
Lifespan of solutions for the nonlinear Schrödinger equation without gauge invarianceNov 29 2012Dec 06 2012We study the lifespan of solutions for the nonlinear Schr\"odinger equation id_{t}u+{\Delta}u={\lambda}|u|^{p}, (t,x)\in[0,T)\timesR^{n}, with the initial condition, where 1<p\leq 1+2/n and {\lambda}\in C. Our main aim in this paper is to prove an upper ... More
Electron Surfing Acceleration in Magnetic ReconnectionJul 22 2005We discuss that energetic electrons are generated near the X-type magnetic reconnection region due to a surfing acceleration mechanism. In a thin plasma sheet, the polarization electric fields pointing towards the neutral sheet are induced around the ... More
Particle Acceleration during Magnetorotational Instability in a Collisionless Accretion DiskJun 28 2013Particle acceleration during the magnetorotational instability (MRI) in a collisionless accretion disk was investigated by using a particle-in-cell (PIC) simulation. We discuss the important role that magnetic reconnection plays not only on the saturation ... More
Can a galaxy redshift survey measure dark energy clustering?Jun 21 2006Aug 23 2006(abridged) A wide-field galaxy redshift survey allows one to probe galaxy clustering at largest spatial scales, which carries an invaluable information on horizon-scale physics complementarily to the cosmic microwave background (CMB). Assuming the planned ... More
Small steps towards Grand Unification and the electron/positron excesses in cosmic-ray experimentsJun 25 2009We consider a small extension of the standard model by adding two Majorana fermions; those are adjoint representations of the SU(2)_L and SU(3)_c gauge groups of the standard model. In this extension, the gauge coupling unification at an energy scale ... More
Semileptonic B Decays and Determination of |Vub|May 24 2005Aug 03 2005Semileptonic decays of the B mesons provide an excellent probe for the weak and strong interactions of the bottom quark. The large data samples collected at the B Factories have pushed the experimental studies of the semileptonic B decays to a new height ... More
Condition for Primordial Black Hole Formation in Randall-Sundrum CosmologyMar 30 2004Apr 19 2004We consider spherical collapse in the Randall-Sundrum type II model and estimate the critical over density for black hole formation in the radiation dominated era. It is found that when (density)$^{2}$-term is dominant in the modified Friedmann equation ... More
Moduli problem and Q-ball baryogenesis in gauge-mediated SUSY breaking modelsFeb 04 2002We investigate whether the Affleck-Dine mechanism can produce sufficient baryon number of the universe in the gauge-mediated SUSY breaking models, while evading the cosmological moduli problem by late-time entropy production. We find that the Q-ball formation ... More
Quantum Energy Teleportation in Spin Chain SystemsMar 04 2008Dec 22 2008We propose a protocol for quantum energy teleportation which transports energy in spin chains to distant sites only by local operations and classical communication. By utilizing ground-state entanglement and notion of negative energy density region, energy ... More
Quantum Energy Teleportation: An Introductory ReviewJan 20 2011The development of techniques for manipulation of quantum information has opened the door to a variety of protocols for accomplishing unprecedented tasks. In particular, a new protocol of quantum teleportation was proposed in 2008 to achieve effective ... More
Ground-State Entanglement gives birth to Quantum Energy TeleportationNov 17 2009Ground-state entanglement induces emergence of negative-energy-density regions in quantum systems by squeezing zero-point oscillation, keeping total energy of the systems nonnegative. By use of the negativity of quantum energy density, protocols of quantum ... More
Quantum Measurement Information as a key to Energy Release from Local VacuumsMar 15 2008Jul 16 2008In this paper, a protocol is proposed in which energy extraction from local vacuum states is possible by using quantum measurement information for the vacuum state of quantum fields. In the protocol, Alice, who stays at a spatial point, excites the ground ... More
Realization of the open-boundary totally asymmetric simple exclusion process on a ringApr 21 2014We propose a misanthrope process, defined on a ring, which realizes the totally asymmetric simple exclusion process with open boundaries. In the misanthrope process, particles have no exclusion interactions in contrast to those in the simple exclusion ... More
Search for Physics Beyond Standard Model at HERAOct 11 1999The latest status of searches at HERA for physics beyond the Standard Model is summarized on behalf of the H1 and ZEUS collaborations. Emphasis is put on production of resonant particles accessible within the HERA center-of-mass energy, such as leptoquarks, ... More
Three Generations or More for an Attractive Gravity?Apr 08 1995We calculate the induced Einstein action from supersymmetric models in general space-time. Supersymmetric models consist of two kinds of supermultiplets, called scalar supermultiplets and vector supermultiplets, respectively. We show that the vector multiplets ... More
The Heat Operator of a Transversally Elliptic OperatorMay 25 2017Let $G$ be a connected compact Lie group. We study the heat operator of a $G$-transversally elliptic operator. After we review the spectral properties of a $G$-transversally elliptic operator, we define the character, that is a distribution on $G$ generalizing ... More
Note on relations among multiple zeta-star valuesJun 02 2011Nov 13 2011In this note, by using several ideas of other researchers, we derive several relations among multiple zeta-star values from the hypergeometric identities of C. Krattenthaler and T. Rivoal.
QPSK coherent state discrimination via a hybrid receiverApr 04 2012Jun 26 2012We propose and experimentally demonstrate a near-optimal discrimination scheme for the quadrature phase shift keying protocol (QPSK). We show in theory that the performance of our hybrid scheme is superior to the standard scheme - heterodyne detection ... More
RNA interference and Register Machines (extended abstract)Nov 17 2012RNA interference (RNAi) is a mechanism whereby small RNAs (siRNAs) directly control gene expression without assistance from proteins. This mechanism consists of interactions between RNAs and small RNAs both of which may be single or double stranded. The ... More
Quantum Energy Teleportation with Electromagnetic Field: Discrete vs. Continuous VariablesAug 19 2009Jan 21 2010It is well known that usual quantum teleportation protocols cannot transport energy. Recently, new protocols called quantum energy teleportation (QET) have been proposed, which transport energy by local operations and classical communication with the ... More
A Protocol for Quantum Energy DistributionMar 11 2008Jul 10 2008A new protocol, quantum energy distribution (QED), is proposed in which multiple parties can simultaneously extract positive energy from spin chains by common secret keys shared by an energy supplier. QED is robust against impersonation; an adversary, ... More
Adaptive Learning in Cartesian Product of Reproducing Kernel Hilbert SpacesAug 05 2014Nov 05 2014We propose a novel adaptive learning algorithm based on iterative orthogonal projections in the Cartesian product of multiple reproducing kernel Hilbert spaces (RKHSs). The task is estimating/tracking nonlinear functions which are supposed to contain ... More
Triangulations of non-proper semialgebraic Thom mapsJun 24 2010In [5] I solved the Thom's conjecture that a proper Thom map is triangulable. In this paper I drop the properness condition in the semialgebraic case and, moreover, in the definable case in an o-minimal structure.