August 2003 arXiv papers — page 6

T. Kobayashi, Y. Komori, K. Yoshida, J. Nishimura

Evidences of non-thermal X-ray emission and TeV gamma-rays from the supernova remnants (SNRs) has strengthened the hypothesis that primary Galactic cosmic-ray electrons are accelerated in SNRs. High energy electrons lose energy via synchrotron and inverse Compton processes during propagation in the Galaxy. Due to these radiative losses, TeV electrons liberat

Myung Goon Lee, Hong Soo Park, Jang-Hyun Park, Young-Jong Sohn

We present deep wide field $VI$ CCD photometry of the Sextans dwarf spheroidal galaxy (dSph) in the Local Group, covering a field of 42' x 28' located at the center of the galaxy. Color-magnitude diagrams of the Sextans dSph show well-defined red giant branch (RGB), blue horizontal branch (BHB), prominent red horizontal branch (RHB), asymptotic giant

S. Rahvar, M. Moniez, R. Ansari, O. Perdereau

In this article, we have investigated the possibility to distinguish between different galactic models through the microlensing parallax studies. We show that a systematic search for parallax effects can be done using the currently running alert systems and complementary photometric telescopes, to distinguish between different lens distance distributions. We

Shin'ichi Nojiri, Sergei D. Odintsov

The modified gravity with $\ln R$ or $R^{-n} (\ln R)^m$ terms which grow at small curvature is discussed. It is shown that such a model which has well-defined newtonian limit may eliminate the need for dark energy and may provide the current cosmic acceleration. It is demonstrated that $R^2$ terms are important not only for early time inflation but also to a

G. M. Bernstein, D. E. Trilling, R. L. Allen, M. E. Brown

[Condensed] We search 0.02 deg^2 for trans-Neptunian objects (TNOs) with m<=29.2 (diameter ~15 km) using the ACS on HST. Three new objects are discovered, roughly 25 times fewer than expected from extrapolation of the differential sky density Sigma(m) of brighter objects. The ACS and other recent TNO surveys show departures from a power law size distribution

Anatoly Golub, Yshai Avishai

The physics of a system consisting of an Aharonov Bohm (AB) interferometer containing a single level interacting quantum dot (QD) on one of its arms, and attached to normal (N) and superconducting (S) leads is studied and elucidated. Here the focus is directed mainly on N-AB-S junctions but the theory is capable of studying S-AB-S junctions as well. The inte

Martin White, Subhabrata Majumdar

We look at the impact of Infra-Red (IR) and radio point sources on upcoming large yield Sunyaev-Zel&#39;dovich (SZ) cluster surveys such as APEX, SPT and ACT. The IR and radio point source counts are based on observations by the the SCUBA and WMAP instruments respectively. We show that the contributions from IR source counts, when extrapolated from the SCUBA

J. S. Alcaniz, J. A. S. Lima

An exotic dark component, named generalized Chaplygin gas (Cg) and parameterized by an equation of state $p = -A/ρ_{Cg}^α$ where $A$ and $α$ are arbitrary constants, is one of the possible candidates for dark energy as well as for a unified scenario of dark matter/energy. In this paper we investigate qualitative and quantitative aspects of the angular size -

Gor Sarkissian, Marija Zamaklar

We study classes of D-branes embedded in various AdS^m x S^n x S^p x T^q backgrounds, which nontrivially mix the target-space submanifolds. Mixing is achieved either via diagonal geometric embedding or through a mixed worldvolume flux which has one index in the sphere and one index in the AdS part. Branes of the former type wrap calibrated cycles in the targ

You-Quan Li, Guo-Qiang Zhu

The concurrence vectors are proposed by employing the fundamental representation of $A_n$ Lie algebra, which provides a clear criterion to evaluate the entanglement of bipartite system of arbitrary dimension for both pure and mixed states. Accordingly, a state is separable if the norm of its concurrence vector vanishes. The state vectors related to SU(3) sta

Thomas Keilen

Francesco Severi showed that equisingular families of plane nodal curves are T-smooth, i.e. smooth of the expected dimension, whenever they are non-empty. For families with more complicated singularities this is no longer true. Given a divisor D on a smooth projective surface it thus makes sense to look for conditions which ensure that the family V of irredu

Kazumi Okuyama

Following hep-th/0305177, we write the boundary state of half S-brane in bosonic string theory as a grand canonical partition function of a unitary matrix model. From this representation, it follows that the annulus amplitude can be written as a grand canonical partition function of a unitary two-matrix model. We also show that the contribution of the expone

S. Sharma, J. K. Dewhurst, C. Ambrosch-Draxl

In this work the mechanism of Li insertion/intercalation in the anode materials InSb and Cu$_2$Sb is investigated by means of the first principles total energy calculations. The total charge densities for the lithiated products of the two compounds are presented. Based on these results the change in the bonding character on lithiation is discussed. Further,

A. De Martino, M. Marsili, R. Mulet

We introduce a simple lattice model of traffic flow in a city where drivers optimize their route-selection in time in order to avoid traffic jams, and study its phase structure as a function of the density of vehicles and of the drivers&#39; behavioral parameters via numerical simulations and mean-field analytical arguments. We identify a phase transition be

G. P. Dubois-Felsmann, D. G. Hitlin, F. C. Porter, G. Eigen

There is now a rapidly growing body of experimental data relevant to the question of whether the standard model CKM quark mixing matrix is a correct description of \CP-violation as well as of non--\CP-violating flavor decay processes. In the detailed comparisons with theoretical predictions that are required to investigate this, a key challenge has been the

Sung Joon Moon, J. B. Swift, Harry L. Swinney

Particles in granular flows are often modeled as frictionless (smooth) inelastic spheres; however, there exist no frictionless grains, just as there are no elastic grains. Our molecular dynamics simulations reveal that friction is essential for realistic modeling of vertically oscillated granular layers: simulations of frictionless particles yield patterns w

Wim van Saarloos

This paper is an introductory review of the problem of front propagation into unstable states. Our presentation is centered around the concept of the asymptotic linear spreading velocity v*, the asymptotic rate with which initially localized perturbations spread into an unstable state according to the linear dynamical equations obtained by linearizing the fu

E. A. Paschos

I present the theoretical basis for Leptogenesis and its implications for the structure of the universe. It is suggested that density fluctuations grow during the transition period and remnants of this effect should be sought in the universe. The relation between theories with Majorana neutrinos and low energy phenomena, including oscillations, advanced cons

F. E. Meijer, A. F. Morpurgo, T. M. Klapwijk, J. Nitta

We discuss a statistical analysis of Aharonov-Bohm conductance oscillations measured in a two-dimensional ring, in the presence of Rashba spin-orbit interaction. Measurements performed at different values of gate voltage are used to calculate the ensemble-averaged modulus of the Fourier spectrum and, at each frequency, the standard deviation associated to th

Dong-Sheng Du, Jing-Wu Li, Mao-Zhi Yang

We calculate $D_s^+\to ϕ$ transition form factors $V$, $A_0$, $A_1$ and $A_2$, and study semileptonic decay of $D_s^+\to ϕ\bar{\ell}ν$ based on QCD sum rule method. We compare our results of the ratios of $V(0)/A_1(0)$, $A_2(0)/A_1(0)$, $Γ_L/Γ_T$, and the total decay branching ratio of $D_s^+\to ϕ\bar{\ell}ν$ with experimental data, and find that they are co

Anastasia Niarchou, Andrew H. Jaffe, Levon Pogosian

One of the most tantalizing results from the WMAP experiment is the suggestion that the power at large scales is anomalously low when compared to the prediction of the ``standard&#39;&#39; Lambda-CDM model. The same anomaly, although with somewhat larger uncertainty, was also previously noted in the COBE data. In this work we discuss possible alternate model

Ali Imaanpur

We study zero modes of N=1/2 supersymmetric Yang-Mills action in the background of instantons. In this background, because of a quartic antichiral fermionic term in the action, the fermionic solutions of the equations of motion are not in general zero modes of the action. Hence, when there are fermionic solutions, the action is no longer minimized by instant

Silvia Petroni, Giuseppe Bono, Marcella Marconi, Robert F. Stellingwerf

We constructed several sequences of classical Cepheid envelope models at solar chemical composition ($Y=0.28, Z=0.02$) to investigate the dependence of the pulsation properties predicted by linear and nonlinear hydrodynamical models on input physics. To study the dependence on the equation of state (EOS) we performed several numerical experiments by using th

Vestislav Apostolov, Tedi Draghici, Andrei Moroianu

An odd-dimensional version of the Goldberg conjecture was formulated and proved by Boyer and Galicki, using an orbifold analogue of Sekigawa&#39;s formulas, and an approximation argument of K-contact structures with quasi-regular ones. We provide here another proof of this result and give some applications.

Yeo-Yie Charng, Hsiang-nan Li

We propose a parametrization for two-body nonleptonic $B$ meson decays, in which the various topologies of amplitudes are counted in terms of powers of the Wolfenstein parameter $λ\sim 0.22$. The weak phases and the amplitudes are determined by comparing this parametrization with available measurements. It is possible to obtain the phase $ϕ_3$ from the $B\to

Carsten Henkel, Karl Joulain, Jean-Philippe Mulet, Jean-Jacques Greffet

The Casimir force between metallic plates made of realistic materials is evaluated for distances in the nanometer range. A spectrum over real frequencies is introduced and shows narrow peaks due to surface resonances (plasmon polaritons or phonon polaritons) that are coupled across the vacuum gap. We demonstrate that the Casimir force originates from the att

Qing-Guo Huang, Miao Li

The first year results of WMAP tentatively indicate running of the spectral index as well as a deficit of power in the low multipoles in the CMB spectrum. The former can be rather easily understood in the noncommutative inflation model, and the latter, as we shall show in this paper, still appears to be an anomaly, even though the noncommutative inflation mo

Lars M. Johansen

Hall&#39;s recent derivation of an exact uncertainty relation [Phys. Rev. A64, 052103 (2001)] is revisited. It is found that the Bayes estimator of an observable between pre- and postselection equals the real part of the weak value. The quadratic loss function equals the expectation of the squared imaginary part of the weak value.

T. Nagata, M. Urata, H. Kawano-Furukawa, H. Yoshizawa

It has been proposed that Sr_2RuO_4 exhibits spin triplet superconductivity mediated by ferromagnetic fluctuations. So far neutron scattering experiments have failed to detect any clear evidence of ferromagnetic spin fluctuations but, instead, this type of experiments has been successful in confirming the existence of incommensurate spin fluctuations near q=

Junji Hisano, Yasuhiro Shimizu

The correlation between the CP asymmetry in $B\to ϕK_s$ ($S_{ϕK_s}$) and the chromoelectric dipole moment (CEDM) of strange quark ($d_s^C$), which is constrained by the electric dipole moment (EDM) of $^{199}$Hg, is studied in the supersymmetric (SUSY) models with the right-handed squark mixing. It is known that, if the right-handed bottom and strange squark

Charles L. Steinhardt

Recent theoretical ideas and observational claims suggest that the fine structure constant alpha may be variable. We examine a spectrum of models in which alpha is a function of a scalar field. Specifically, we consider three scenarios: oscillating alpha, monotonic time variation of alpha, and time-independent alpha that is spatially varying. We examine the

R. Foot

Mirror atoms are expected to be a significant component of the galactic dark matter halo if mirror matter is identified with the non-baryonic dark matter in the Universe. Mirror matter can interact with ordinary matter via gravity and via the photon-mirror photon kinetic mixing interaction -- causing mirror charged particles to couple to ordinary photons wit

M. Atakan Gürkan, Marc Freitag, Frederic A. Rasio

We study the early dynamical evolution of young, dense star clusters using Monte Carlo simulations for systems with up to N~10^7 stars. Rapid mass segregation of massive main-sequence stars and the development of the Spitzer instability can drive these systems to core collapse in a small fraction of the initial half-mass relaxation time. If the core collapse

A. V. Dodonov, E. V. Dodonov, V. V. Dodonov

We study the influence of fluctuations in periodic motion of boundaries of an ideal three-dimensional cavity on the rate of photon generation from vacuum due to the nonstationary Casimir effect.

Cecilia Noguez, Carlos E. Roman-Velazquez, R. Esquivel-Sirvent, C. Villarreal

We show that the dispersive force between a spherical nanoparticle (with a radius $\le$ 100 nm) and a substrate is enhanced by several orders of magnitude when the sphere is near to the substrate. We calculate exactly the dispersive force in the non-retarded limit by incorporating the contributions to the interaction from of all the multipolar electromagneti

Zai-Zhe Zhong

In this Letter we find the new criteria of separability of multipartite qubit density matrixes. Especially, we discuss in detail the criteria of separability for tripartite qubit density matrixes. We find the sufficient and necessary conditions of separability for tripartite qubit density matrixes, and give two corollaries. The second corollary can be taken

Stephen D. Bartlett, H. M. Wiseman

Bipartite entanglement may be reduced if there are restrictions on allowed local operations. We introduce the concept of a generalized superselection rule (SSR) to describe such restrictions, and quantify the entanglement constrained by it. We show that ensemble quantum information processing, where elements in the ensemble are not individually addressable,

S. Horvat, O. Kortner, H. Kroha, A. Manz

ATLAS is a detector under construction to explore the physics at the Large Hadron Collider at CERN. It has a muon spectrometer with an excellent momentum resolution of 3-10%, provided by three layers of precision monitored-drift-tube chambers in a toroidal magnetic field. A single drift tube measures a track point with a mean resolution close to 100 micron,

A. Mary Selvam

The complex spatiotemporal patterns of atmospheric flows resulting from the cooperative existence of fluctuations ranging in size from millimeters to thousands of kilometers are found to exhibit long-range spatial and temporal correlations manifested as the selfsimilar fractal geometry to the global cloud cover pattern and the inverse power law form for the

M. T. Yamashita, T. Frederico, R. S. Marques de Carvalho, Lauro Tomio

A renormalized three-body model with zero-range potential is used to estimate the mean-square radii of three-body halo nuclei and molecular systems. The halo nuclei ($^6$He, $^{11}$Li, $^{14}$Be and $^{20}$C) are described as point-like inert cores and two neutrons. The molecular systems, with two helium atoms, are of the type $^4$He$_2-$X, where X$=^4$He, $

Gentaro Watanabe, Kei Iida

Screening effects of electrons on inhomogeneous nuclear matter, which includes spherical, slablike, and rodlike nuclei as well as spherical and rodlike nuclear bubbles, are investigated in view of possible application to cold neutron star matter and supernova matter at subnuclear densities. Using a compressible liquid-drop model incorporating uncertainties i

M. M. Mustafa, E. M. Darwish, E. A. M. Sultan, E. M. Hassan

A new value $b=0.0205\pm0.0017$ fm$^2$ of the slope of the neutron form factor $G_{En}(q^2)$ at $q^2=0$ compatible with deuteron properties has been extracted by using a linear relation between $b$ and $A^2_S(1+η^2)$ we found for a class of nonlocal potential models having the experimental values of both $r_D$ and $Q$. Another {\it model dependent} value $b^

S. Strauch

I argue that the double ratio of proton-recoil polarization-transfer coefficients, P&#39;_x and P&#39;_z, of the quasielastic 4He(e,e&#39;p)3H reaction with respect to the elastic 1H(e,e&#39;p) reaction is sensitive to possible medium modifications of the proton form factor in 4He. Recent measurements at both Mainz and Jefferson Lab of this double ratio at f

K. -H. Glander, J. Barth, W. Braun, J. Hannappel

The reactions gamma p --> K+ Lambda and gamma p --> K+ Sigma0 were measured in the energy range from threshold up to a photon energy of 2.6 GeV. The data were taken with the SAPHIR detector at the electron stretcher facility, ELSA. Results on cross sections and hyperon polarizations are presented as a function of kaon production angle and photon energy. The

A. M. Rucklidge, A. R. Champneys

It is well established that the onset of spatially periodic vortex states in the Taylor-Couette flow between rotating cylinders occurs at the value of Reynold&#39;s number predicted by local bifurcation theory. However, the symmetry breaking induced by the top and bottom plates means that the true situation should be a disconnected pitchfork. Indeed, experim

W. -S. Son, I. Kim, Y. -J. Park, C. -M. Kim

The intermittency is investigated when the current reversal occurs in a deterministic inertia ratchet system. To determine which type the intermittency belongs to, we obtain the return map of velocities of particle using stroboscopic recording, and numerically calculate the distribution of average laminar length ${<}l{>}$. The distribution follows the scalin

Soeren Koester

We study inclusions of local, chiral, conformal quantum theories C which are contained in an ambient theory B and commute with another given subtheory A. These subtheories C are called Coset models. Most of our results are model-independent, although our analysis is motivated by the inclusions of current algebras and their Coset models. We prove that to ever

Eric Weber

In this short note we show two results concerning sampling translation invariant subspaces of $\ltwod$ on unions of lattices. The first result shows that the sampling transform on a union of lattices is a constant times an isometry if and only if the sampling transform on each individual lattice is so. The second result demonstrates that the sampling transfo

Akram Aldroubi, David Larson, Wai-Shing Tang, Eric Weber

We consider frames arising from the action of a unitary representation of a discrete countable abelian group. We show that the range of the analysis operator can be determined by computing which characters appear in the representation. This allows one to compare the ranges of two such frames, which is useful for determining similarity and also for multiplexi

Xianzhe Dai

We prove a positive mass theorem for spaces which asymptotically approach a flat Euclidean space times a Calabi-Yau manifold (or any special honolomy manifold except the quaternionic Kähler). This is motivated by the very recent work of Hertog-Horowitz-Maeda.

Yi-Zhi Huang, Liang Kong

We introduce notions of open-string vertex algebra, conformal open-string vertex algebra and variants of these notions. These are ``open-string-theoretic,&#39;&#39; ``noncommutative&#39;&#39; generalizations of the notions of vertex algebra and of conformal vertex algebra. Given an open-string vertex algebra, we show that there exists a vertex algebra, which

Regis Pellissier

This thesis is devoted to the proof of a theorem showing the existence of a closed model category structure for weakly enriched categories. It requires first of all the definitions of weakly enriched categories and equivalences of weakly enriched categories such that these definitions recover some existing notions of higher order weak categories, for example

Michael Skeide

Starting from elementary considerations about independence and Markov processes in classical probability we arrive at the new concept of conditional monotone independence (or operator-valued monotone independence). With the help of product systems of Hilbert modules we show that monotone conditional independence arises naturally in dilation theory.

C. Bartocci, I. Mencattini

We prove that an integrable system over a symplectic manifold, whose symplectic form is covariantly constant w.r.t. the Gauss-Manin connection, carries a natural hyper-symplectic structure. Moreover, a special Kaehler structure is induced on the base manifold.

Barbu Berceanu, Martin Markl, Stefan Papadima

W. Fulton and R. MacPherson described a Sullivan dg-algebra model for the space of n-configurations of labeled points in a smooth compact complex algebraic variety X. I. Kriz then gave a simpler model that depends only on the cohomology ring of X. We construct an even simpler and substantially smaller model for this configuration space. Using this smaller mo

Victor Shulman, Lyudmila Turowska

The interplay between the invariant subspace theory and spectral synthesis for locally compact abelian group discovered by Arveson is extended to include other topics as harmonic analysis for Varopoulos algebras and approximation by projection-valued measures. We propose a &#39;&#39;coordinate&#39;&#39; approach which nevertheless does not use the technique

Igor Rivin

We investigate the space of simplices in Euclidean Space

Peter Friz, Nicolas Victoir

A geometric p-rough path can be seen to be a genuine path of finite p-variation with values in a Lie group equipped with a natural distance. The group and its distance lift (R^{d},+,0) and its Euclidean distance. This approach allows us to easily get a precise modulus of continuity for the Enhanced Brownian Motion (the Brownian Motion and its Levy Area). As

Andrey Todorov

In this paper the relations between the existence of Lagrangian fibration of Hyper-Kähler manifolds and the existence of the Large Radius Limit is established. It is proved that if the the rank of the second homology group of a Hyper-Kähler manifold N of complex dimension $2n\geq4$ is at least 5, then there exists an unipotent element T in the mapping class

I. A. Batalin, A. M. Semikhatov

We show that the associative algebra structure can be incorporated in the BRST quantization formalism for gauge theories such that extension from the corresponding Lie algebra to the associative algebra is achieved using operator quantization of reducible gauge theories. The BRST differential that encodes the associativity of the algebra multiplication is co

Eva Silverstein

Flux compactifications of string theory exhibiting the possibility of discretely tuning the cosmological constant to small values have been constructed. The highly tuned vacua in this discretuum have curvature radii which scale as large powers of the flux quantum numbers, exponential in the number of cycles in the compactification. By the arguments of Susski

Jennie Traschen

We study transverse asymptotically flat spacetimes without horizons that arise from brane matter sources. We assume that asymptotically there is a spatial translation Killing vector that is tangent to the brane. Such spacetimes are characterized by a tension, analogous to the ADM mass, which is a gravitational charge associated with the asymptotic spatial tr

Kunihito Uzawa

We investigate dilaton stabilization in a higher-dimensional theory. The background geometry is based on an eleven-dimensional Kaluza-Klein/supergravity model, which is assumed to be a product of four-dimensional de Sitter (dS_4) spacetime and a seven sphere. The dilaton potential has a local minimum resulting from contributions of the cosmological constant,

T. G. Philbin

This paper has been withdrawn because of serious errors.

O. Linnyk, S. Leupold, U. Mosel

Non-perturbative corrections to the LO cross section formulae for DIS and the Drell-Yan process were calculated. The interaction of partons was taken into account via dressing the incoming quark lines with spectral functions. We found the effect of ground state correlation in DIS to be large in the region of small Bjorken x and low momentum transfer Q. For a

J. Hofmann, M. F. M. Lutz

We study heavy-light meson resonances with quantum numbers J^P=0^+ and J^P=1^+ in terms of the non-linear chiral SU(3) Lagrangian. Adjusting the free parameters that arise at subleading order to reproduce the mass of the D(2420) resonance as well as the new states established recently by the BABAR, CLEO and BELLE collaborations we obtain refined masses for t

A. G. Akeroyd

We investigate the effect of a charged Higgs boson (H^\pm) on the decays D^\pm_s\to μ^\pmνand D^\pm_s\to τ^\pmν, which will be measured with high precision at forthcoming CLEO-c. We show that a H^\pm can suppress the branching ratios by 10% \to 15% from the Standard Model prediction, and we emphasize that such contributions should not be overlooked when comp

Masako Bando, Taichiro Kugo

Under the assumptions that 1) the quark/lepton mass matrices take Froggatt-Nielsen&#39;s factorized power form λ^{ψ_i+ψ_j} with anomalous U(1) charges ψ_i, and 2) the U(1) charges ψ_i respect the SU(5) GUT structure, we show that the quark mass data and the mass-squared difference ratio of solar and atmospheric neutrinos, as inputs, necessarily imply that bo

Gongru Lu, Rumin Wang, Yadong Yang

We investigate the physics potential of the annihilation decays $\bar{B}^0_{s,d} \to J/ψ$ $γ$ in the Standard Model and beyond. In naive factorization approach, the branching ratios are estimated to be $\mathcal{B}(\bar{B}^0_s \to J/ψγ)=1.40\times 10^{-6}$ and $\mathcal{B}(\bar{B}^0_d \to J/ψγ)=5.29\times 10^{-8}$. In the framework of QCD factorization, we c

David N. Walters, Simon Hands

Monte Carlo simulations of the 3+1 dimensional NJL model are performed with baryon chemical potential mu>0. For mu>Sigma_0, the constituent quark mass in vacuum, chiral symmetry is restored and a diquark condensate <qq_+> forms. We analyse the fermion propagator and find evidence for particle-hole mixing in the vicinity of the Fermi surface and an energy gap

I. Horvath, S. J. Dong, T. Draper, F. X. Lee

Lattice topological charge associated with Ginsparg-Wilson fermions exhibits generic topological stability over quantum ensemble of configurations contributing to the QCD path integral. Moreover, the underlying chiral symmetry leads to the suppression of ultraviolet noise in the associated topological charge densities (&#34;chiral smoothing&#34;). This provi

William Morse

A precision measurement of the anomalous magnetic moment (g-2) of the muon has been made by the E821 collaboration at BNL. This paper is a written version of a ``hot topics&#39;&#39; talk at ICAP2002 (Cambridge, MA). The principles of the experiment are discussed, especially the beam dynamics aspects.

Y. K. Semertzidis, M. Aoki, M. Auzinsh, V. Balakin

In this paper a new method is presented for particles in storage rings which could reach a statistical sensitivity of 10**(-27) e cm for the deuteron EDM. This implies an improvement of two orders of magnitude over the present best limits on the T-odd nuclear forces ksi parameter.

Hartmut Abele

Measurements by various international groups of researchers determine the strength of the weak interaction of the neutron, which gives us unique information on the question of the quark mixing. Neutron decay experiments now challenge the Standard Model of elementary particle physics with a deviation, 2.7 times the stated error.

Julien Sylvestre, Massimo Tinto

We consider the general problem of estimating the inflight LISA noise power spectra and cross-spectra, which are needed for detecting and estimating the gravitational wave signals present in the LISA data. For the LISA baseline design and in the long wavelength limit, we bound the error on all spectrum estimators that rely on the use of the fully symmetric S

J. W. Maluf, J. F. da Rocha-Neto

Considering the vacuum as characterized by the presence of only the gravitational field, we show that the vacuum energy density of the de Sitter space, in the realm of the teleparallel equivalent of general relativity, can acquire arbitrarily high values. This feature is expected to hold in the consideration of realistic cosmological models, and may possibly

Robin W. Tucker

With the aid of a Fermi-Walker chart associated with an orthonormal frame attached to a time-like curve in spacetime, a discussion is given of relativistic balance laws that may be used to construct models of massive particles with spin, electric charge and a magnetic moment,interacting with background electromagnetic fields and gravitation described by non-

Zvonimir Dogic

We study the kinetics of the isotropic-smectic phase transition in a colloidal rod/polymer mixture by visualizing individual smectic layers. First, we show that the bulk isotropic-smectic phase transition is preceded by a surface freezing transition in which a quasi two-dimensional smectic phase wets the isotropic-nematic interface. Next, we identify a two s

S. N. Klimin, J. T. Devreese

Cyclotron-resonance (CR) spectra of a gas of interacting polarons confined in a GaAs/AlAs quantum well are theoretically investigated taking into account the magneto-plasmon-phonon mixing and band nonparabolicity. Contributions of different magneto-plasmon-phonon modes to the total magneto-polaron coupling strength are investigated as a function of the elect

Carlos E. Roman-Velazquez, Cecilia Noguez, Ignacio L. garzon

Circular dichroism (CD) spectra of chiral bare and thiol-passivated gold nanoclusters have been calculated within the dipole approximation. The calculated CD spectra show features that allow us to distinguish between clusters with different indexes of chirality. The main factor responsible of the differences in the CD lineshapes is the distribution of intera

A. C. Graham, K. J. Thomas, M. Pepper, N. R. Cooper

We report conductance measurements of ballistic one-dimensional (1D) wires defined in GaAs/AlGaAs heterostructures in an in-plane magnetic field, B. When the Zeeman energy is equal to the 1D subband energy spacing, the spin-split subband N(up-spin) intersects (N+1)(down-spin), where N is the index of the spin-degenerate 1D subband. At the crossing of N=1(up-

R. Meyer, L. J. Lewis, S. Prakash, P. Entel

The vibrational density of states (VDOS) of nanoclusters and nanocrystalline materials are derived from molecular-dynamics simulations using empirical tight-binding potentials. The results show that the VDOS inside nanoclusters can be understood as that of the corresponding bulk system compressed by the capillary pressure. At the surface of the nanoparticles

Jorgen Vitting Andersen

It is suggested to consider long term trends of financial markets as a growth phenomenon. The question that is asked is what conditions are needed for a long term sustainable growth or contraction in a financial market? The paper discuss the role of traditional market players of long only mutual funds versus hedge funds which take both short and long positio

Shirish M. Chitanvis

Using a continuum description, we account for fluctuations in the ionic solvent surrounding a Gaussian, charged chain and derive an effective short-ranged potential between the charges on the chain. This potential is repulsive at short separations and attractive at longer distances. The chemical potential can be derived from this potential. When the chemical

A. Zheludev, S. M. Shapiro, Z. Honda, K. Katsumata

We report the results of elastic and inelastic neutron scattering experiments on the Haldane gap quantum antiferromagnet Ni(C5D14N2)2N3(PF6) performed at mK temperatures in a wide range of magnetic field applied parallel to the S = 1 spin chains. Even though this geometry is closest to an ideal axially symmetric configuration, the Haldane gap closes at the c

Petter Holme

Many recent large-scale studies of interaction networks have focused on networks of accumulated contacts. In this paper we explore social networks of ongoing relationships with an emphasis on dynamical aspects. We find a distribution of response times (times between consecutive contacts of different direction between two actors) that has a power-law shape ov

F. Picaud, V. Pouthier, C. Girardet, E. Tosatti

Recent experiments showed that the last, single channel conductance step in monatomic gold contacts exhibits significant fluctuations as a function of stretching. From simulations of a stretched gold nanowire linked to deformable tips, we determine the distribution of the bond lengths between atoms forming the nanocontact and analyze its influence on the ele

R Suryanarayanan, V Gasumyants

Measurements of Seebeck effect in 0 and 1.5 T and Nernst coefficient in 0.3,0.9 and 1.8 T as a function of temperature on a polycrystalline sample Sm0.55Sr0.45MnO3 are presented. The data point out conclusively that an increase inboth the carrier density and the mobility of the charge carriers is responsible for the observed colossal magnetoresistance

Faruque M. Hossain, J. Nishii, S. Takagi, A. Ohtomo

Thin film transistors (TFTs) made of transparent channel semiconductors such as ZnO are of great technological importance, because their insensitivity to visible light makes device structures simple. In fact, several demonstrations are made on ZnO TFT achieving reasonably good field effect mobilities of 1-10 cm2/Vs, but reveal insufficient device performance

Antonio Siber

The structures of long-range ordered physisorbed monolayer on a carbon nanotube are examined. Geometrical and energetical constraints determining the order of such monolayers are discussed. A number of symmetrically different, strongly bound adsorbate structures is found for Xe adsorbates, some of which differ very little in energy. The presented results sug

Silvana Mercone, Vincent Hardy, Christine Martin, Charles Simon

We have studied by small angle neutron scattering the evolution induced by the application of magnetic field of the coexistence of ferromagnetism (F) and antiferromagnetism (AF) in a crystal of Pr$_{0.67}$Ca$_{0.33}$MnO$_3$. The results are compared to magnetic measurements which provide the evolution of the ferromagnetic fraction. These results show that th

R. Gilardi, J. Mesot, A. J. Drew, U. Divakar

We report on a small angle neutron scattering study of the vortex lattice in overdoped La{2-x}Sr{x}CuO{4} (x=0.2) up to high magnetic fields (9.5 Tesla) applied perpendicular to the CuO2 planes. At low magnetic fields we observe a crossover from hexagonal to square coordination of the vortex lattice. This field-induced transition confirms the results obtaine

S. Moss de Oliveira, D. Stauffer, P. M. C de Oliveira, J. S. Sa Martins

We twice modify the Penna model for biological ageing. First we introduce back (good) mutations and a memory for them into the model. It allows us to observe an improvement of the species fitness over long time scales as well as punctuated equilibrium. Second we adopt a food/space competition factor that depends on the number of accumulated mutations in the

D. Marenduzzo, E. Orlandini, J. M. Yeomans

We use lattice Boltzmann simulations of the Beris--Edwards formulation of nematodynamics to probe the response of a nematic liquid crystal with conflicting anchoring at the boundaries under shear and Poiseuille flow. The geometry we focus on is that of the hybrid aligned nematic (HAN) cell, common in devices. In the nematic phase, backflow effects resulting

Yashodhan Hatwalne, Sriram Ramaswamy, Madan Rao, R. Aditi Simha

We study the interplay of activity, order and flow through a set of coarse-grained equations governing the hydrodynamic velocity, concentration and stress fields in a suspension of active, energy-dissipating particles. We make several predictions for the rheology of such systems, which can be tested on bacterial suspensions, cell extracts with motors and fil

D. Katayama, A. Sumiyama, Y. Oda

The diamagnetism of platinum metals (N: Rh, Pt, Pd), which is induced by the proximity effect of a superconductor (S: Nb), has been investigated for N-S double layers. Notwithstanding the strong spin fluctuation in platinum metals, the screening distance ρin N increases with a decrease in temperature and reaches a value which is expected in comparison with ρ

B. Sanyal, O. Bengone, S. Mirbt

Mn doped semiconductors are extremely interesting systems due to their novel magnetic properties suitable for the spintronics applications. It has been shown recently by both theory and experiment that Mn doped GaN systems have a very high Curie temperature compared to that of Mn doped GaAs systems. To understand the electronic and magnetic properties, we ha

S. Heinze, J. Tersoff, Ph. Avouris

With decreasing device dimensions, the performance of carbon nanotube field-effect transistors (CNFETs) is limited by high Off currents except at low drain voltages. We show that an asymmetric design improves the performance, reducing Off currents and extending the usable range of drain voltage. The improvement is most dramatic for ambipolar Schottky-barrier

P. M. C. de Oliveira, R. A. Nobrega, D. Stauffer

A 1/L-expansion for percolation problems is proposed, where L is the lattice finite length. The square lattice with 27 different sizes L = 18, 22 ... 1594 is considered. Certain spanning probabilities were determined by Monte Carlo simulations, as continuous functions of the site occupation probability p. We estimate the critical threshold pc by applying the

B. Sanyal, L. Bergqvist, O. Eriksson

New materials are currently sought for use in spintronics applications. Ferromagnetic materials with half metallic properties are valuable in this respect. Here we present the electronic structure and magnetic properties of binary compounds consisting of 3d transition metals and group V elements viz. P, Sb and As in the zinc-blende structure. We demonstrate