August 2001 arXiv papers — page 7

K. Matsuda, Y. Koide, T. Fukuyama, H. Nishiura

Can the SO(10) model with one {\bf 10} and one {\bf 126} Higgs scalars give the observed masses and mixings of quarks and leptons without any other additional Higgs scalars? Recently, at least, for quarks and charged leptons, it has been demonstrated that it is possible. However, for the neutrinos, it is usually said that parameters which are determined from

Sergey Porsev, Andrei Derevianko

Relativistic many-body calculations of van der Waals coefficients C_6 for dimers correlating to two ground state alkaline-earth atoms at large internuclear separations are reported. The following values and uncertainties were determined : C_6 = 214(3) for Be, 627(12) for Mg, 2221(15) for Ca, 3170(196) for Sr, and 5160(74) for Ba in atomic units.

D. A. Glazov, V. M. Shabaev

The finite nuclear size correction to the bound-electron g factor in hydrogenlike atoms is investigated in the range Z=1-20. An analytical formula for this correction which includes the non-relativistic and dominant relativistic contributions is derived. In the case of the 1s state, the results obtained by this formula are compared with previous non-relativi

Michael B. Mensky, Alexander V. Yurkin

The distribution of radiation is investigated for the modeless laser having a multilobe mirror with the lobes (planes) inclined by small angles to optical axis. It is shown that change of the direction resulting from many passages of a ray through the optical system including a multilobe mirror may be described as Brownian walk of a point along the plane or

C. Providencia, D. P. Menezes, L. Brito

The caloric curve (excitation energy per particle as a function of temperature) for finite nuclei is calculated within the non-linear Walecka model for different proton fractions and different parameterizations. The results obtained are compared with published experimental data and other theoretical results. Other properties related with the droplet formatio

D. R. Entem, R. Machleidt

We present an accurate nucleon-nucleon ($NN$) potential based upon chiral effective Lagrangians. The model includes one- and two-pion exchange contributions up to chiral order three. We show that a quantitative fit of the $NN$ $D$-wave phase shifts requires contact terms (which represent the short range force) of order four. Within this framework, the $NN$ p

Alberto Polleri, Feng Yuan

We study the dependence of parton energy loss (quenching) on rapidity in ultra-relativistic nuclear collisions at RHIC. This can provides invaluable information on the density of the medium, which should be more dilute going away from mid-rapidity, thereby reducing the effect of quenching. We predict a clear effect at moderate transverse momenta $\sim$ 3 GeV

N. A. Orr

Clustering is a relatively widespread phenomena which takes on many guises across the nuclear landscape. Selected topics concerning the study of halo systems and clustering in light, neutron-rich nuclei are discussed here through illustrative examples taken from the Be isotopic chain.

Volker D. Burkert

Recent results from Jefferson Lab on measurement of inclusive double polarization asymmetries in the nucleon resonance region are discussed. Preliminary results on the first moment of the structure function g_1(x,Q^2) for protons, and on the generalized Gerasimov-Drell-Hearn integral for neutrons are presented as well. The first moment for protons shows a st

Sen-yue Lou, Shun-li Zhang, Xiao-yan Tang

Because of all the known integrable models possess Schwarzian forms with Möbious transformation invariance, it may be one of the best way to find new integrable models starting from some suitable Möbious transformation invariant equations. In this paper, the truncated Painlevé analysis is used to find high dimensional Schwarzian derivatives. Especially, a th

Thomas Prellberg

It is well established that the physical phenomenon of intermittency can be investigated via the spectral analysis of a transfer operator associated with the dynamics of an interval map with indifferent fixed point. We present here for the first time a complete spectral analysis for an example of such an intermittent map, the Farey map. We give a simple proo

Takeshi Fukuyama, Kiyoshi Kamimura, Kouichi Toda

We consider several integrable systems from a standpoint of the SL(2,R) invariant gauge theory. In the Drinfeld-Sokorov gauge, we get a one parameter family of nonlinear equations from zero curvature conditions. For each value of the parameter the equation is described by weak Lax equations. It is transformed to a set of coupled equations which pass the Pain

Thomas Chen

We consider the infrared problem in a model of a freely propagating, nonrelativistic charged particle of mass 1 in interaction with the quantized electromagnetic field. The hamiltonian of the system is regularized by an infrared cutoff $\ssig\ll 1$ and an ultraviolet cutoff $\Lambda\sim 1$ in the interaction term, in units of the mass of the charged particle

G. Sardanashvily

Any leafwise connection on a fibre bundle over a foliated manifold is proved to come from a connection on this fibre bundle.

A. S. Mazurenko, V. A. Savva

An excitation dynamics of new quantum systems of N equidistant energy levels in a monochromatic field has been investigated. To obtain exact analytical solutions of dynamic equations an analytical method based on orthogonal functions of a real argument has been proposed. Using the orthogonal Legendre functions we have found an exact analytical expression for

Christopher J. Pappacena

For a noncommutative space X, we study Inj(X), the set of isomorphism classes of indecomposable injective X-modules. In particular, we look at how this set, suitably topologized, can be viewed as an underlying "spectrum" for X. As applications we discuss noncommutative notions of irreducibility and integrality, and a way of associating an integral su

Timo Seppalainen

We study central limit theorems for a totally asymmetric, one-dimensional interacting random system. The models we work with are the Aldous-Diaconis-Hammersley process and the related stick model. The A-D-H process represents a particle configuration on the line, or a 1-dimensional interface on the plane which moves in one fixed direction through random loca

G. Lusztig

We prove a strong induction theorem for graded Hecke algebras and we classify the tempered and square integrable representations of such algebras using methods of equivariant homology.

G. Lusztig

These are notes for lectures given at MIT in 1999 (Fall). They contain a discussion of affine Hecke algebras with possibly unequal parameters including a theory of cells and a partly conjectural theory of J-rings.

Timo Seppalainen, Sunder Sethuraman

Consider a one-dimensional exclusion process with finite-range translation-invariant jump rates with non-zero drift. Let the process be stationary with product Bernoulli invariant distribution at density ρ. Place a second class particle initially at the origin. For the case ρdifferent from 1/2 we show that the time spent by the second class particle at the o

Emilio Musso, Lorenzo Nicolodi

We establish a correspondence between Darboux's special isothermic surfaces of type (A,0,C,D) and the solutions of the second order PDE : uΔ(u)-|\nabla(u)|^{2}+Φ^{4}=s, s \in R. We then use the classical Darboux transformation for isothermic surfaces to construct a Bäcklund transformation for this equation and prove a superposition formula for its soluti

Martin Schmoll

Asymptotic quadratic growth rates of saddle connections and families of periodic cylinders on translation tori with n marked points are studied. For any marking the existence of limits of the quadratic growth rate is shown using elementary methods (not Ratners theorem). We study the growth rate limit as function of the marking. We give precise formulas for t

Florin Ambro

We prove a precise inversion of adjunction formula for the log pair associated to a non-degenerate hypersurface. As a corollary, the minimal log discrepancies of non-degenerate normal hypersurface singularities are bounded from above by dimension.

S. K. Roushon

We ask if any finite type generalized braid group is a subgroup of some classical Artin braid group. We define a natural map from a given finite type generalized braid group to a classical braid group and ask if this map is an injective homomorphism. We prove that this map is a homomorphism for the braid groups of type A_n, B_n, I_2(k). The injectivity quest

Gunther Cornelissen, Fumiharu Kato

We compute the dimension of the tangent space to, and the Krull dimension of the pro-representable hull of two deformation functors. The first one is the ``algebraic'' deformation functor of an ordinary curve X over a field of positive charateristic with prescribed action of a finite group G, and the data are computed in terms of the ramification beh

Celso M. Doria

Considering that the Seiberg-Witten functional satisfies the Palais-Smale Condition, up to gauge equivalence, the Minimax Principle can be applied on the moduli space to prove the existence of critical points, which correspond to solutions of the second-order SW-equations, up to gauge equivalence.

R. Amorim, J. Barcelos-Neto

Free noncommutative fields constitute a natural and interesting example of constrained theories with higher derivatives. The quantization methods involving constraints in the higher derivative formalism can be nicely applied to these systems. We study real and complex free noncommutative scalar fields where momenta have an infinite number of terms. We show t

D. M. Ghilencea, S. Groot Nibbelink, H. P. Nilles

In the context of a five dimensional N=1 Kaluza Klein model compactified on S_1/Z_2 x Z_2' we compute the one-loop gauge corrections to the self energy of the (zero-mode) scalar field. The result is quadratically divergent due to the appearance of a Fayet-Iliopoulos term.

D. M. Ghilencea, H. P. Nilles, S. Stieberger

Effective field theories with (large) extra dimensions are studied within a physical regularization scheme provided by string theory. Explicit string calculations then allow us to consistently analyze the ultraviolet sensitivity of Kaluza--Klein theories in the presence or absence of low energy supersymmetry.

Jan Plefka, Matthias Staudacher

We present a full two-loop O(g^6) perturbative field theoretic calculation of the expectation value of two circular Maldacena-Wilson loops in D=4 N=4 supersymmetric U(N) gauge theory. It is demonstrated that, after taking into account very subtle cancellations of bulk and boundary divergences, the result is completely finite without any renormalization. As o

H. Weigel

For renormalizable models a method is presented to unambiguously compute the energy that is carried by localized field configurations (solitons). A variational approach for the total energy is utilized to search for soliton configurations. As an example a 1+1 dimensional model is considered. The quantum energy of configurations that are translationally invar

C. Shio

Due to unsuitable attempt to connect the base theory in hep-th/0106074 to noncommutative field theory, this paper has been withdrawn by the author.

V. P. Petrov, G. S. Sharov

For the linear string baryon model with three material points (three quarks) joined sequentially by the relativistic strings, the class of motions admitting linearizable boundary conditions is investigated. These motions may be represented as the Fourier series with eigenfunctions of some boundary-value problem. The two types of rotational motions are found

P. Z. Skands

In the Minimal Supersymmetric Standard Model (MSSM), the simultaneous appearance of lepton and baryon number violation causes the proton to decay much faster than the experimental bound allows. Customarily, a discrete symmetry known as R-parity is imposed to forbid these dangerous interactions. This work begins by arguing that there is no deep theoretical mo

Alexander Khodjamirian

Uses of QCD sum rules for heavy flavoured hadrons are discussed. "Standard" applications such as the determination of the $b$, $c$ quark masses, the calculation of $f_B$, $f_D$ and of the heavy-to-light form factors are overviewed. Furthermore, a new approach to calculate the $B\to ππ$ hadronic matrix elements from QCD light-cone sum rules is describ

H. Athar, Guey-Lin Lin

Absorption of high-energy $\barν_e$ over electrons above the W boson production threshold is reexamined. It is pointed out that, in the case of photon emissions along the direction of incident high-energy $\barν_e$, the kinematically allowed average energy carried by the final state hard photon can be $\leq 1%$ of the incident $\barν_e$ energy above the W bo

Masayasu Harada

In this talk I summarize our recent work on the vector dominance in QCD by using the the hidden local symmetry as an effective field theory of QCD.

L. C. Garcia de Andrade

Spin-polarised cylindrically symmetric solution are shown not to be compatible with teleparallel gravity.This can be done in two distinct manners.The first is to show that not all components of the orthonormal tetrad (OT).It is argue however that this result maybe done by a bad choice of the spin distribution along the cylinder.A cylindrically symmetric Riem

Rodolfo Gambini, Jorge Pullin

We consider discretizations of the Einstein action of general relativity such that the resulting discrete equations of motion form a consistent constrained system. Upon ``spin foam'' quantization of the system, consistency allows a natural way of recovering the correct semi-classical theory. A consistent set of approximations to the Einstein equation

Hajime Sotani, Kazuhiro Tominaga, Kei-ichi Maeda

We calculate quasi-normal f- and g-modes of a neutron star with density discontinuity, which may appear in a phase transition at extreme high density. We find that discontinuity will reflect largely on the f-mode, and that the g-mode could also be important for a less massive star.

Sandra Barsky, Mark O. Robbins

Nonequilibrium molecular dynamics simulations are used to study the shear thinning behavior of immiscible symmetric polymer blends. The phase separated polymers are subjected to a simple shear flow imposed by moving a wall parallel to the fluid-fluid interface. The viscosity begins to shear thin at much lower rates in the bulk than at the interface. The enti

Osame Kinouchi

Receptor cells with electrically coupled axons can improve both their input sensitivity and dynamical range due to collective non-linear wave properties. This mechanism is illustrated by a network of axons modeled by excitable maps subjected to a Poison signal process with rate r. We find that, in a network of N cells, the amplification factor A (number of c

Ulrich H. E. Hansmann, Jose N. Onuchic

We study the thermodynamics and kinetics of folding for a small peptide. Our data rely on Monte Carlo simulations where the interactions among all atoms are taken into account. Monte Carlo kinetics is used to study folding of the peptide at suitable temperatures. The results of these canonical simulations are compared with that of a generalized-ensemble simu

S. Picozzi, R. Asahi, C. B. Geller, A. Continenza

Results are presented of a fully ab-initio calculation of impact ionization rates in GaAs within the density functional theory framework, using a screened-exchange formalism and the highly precise all-electron full-potential linearized augmented plane wave (FLAPW) method. The calculated impact ionization rates show a marked orientation dependence in {\bf k}

Dafang Zheng, G. J. Rodgers, P. M. Hui, R. D'Hulst

We study self-organized models for information transmission and herd behavior in financial markets. Existing models are generalized to take into account the effect of size-dependent fragmentation and coagulation probabilities of groups of agents and to include a demand process. Non-universal scaling with a tunable exponent for the group size distribution is

Olivier Pouliquen, Yoel Forterre

The problem of the spreading of a granular mass released at the top of a rough inclined plane was investigated. We experimentally measure the evolution of the avalanche from the initiation up to the deposit using a Moiré image processing technique. The results are quantitatively compared with the prediction of an hydrodynamic model based on depth averaged eq

K. Ivanova, N. Gospodinova, H. N. Shirer, T. P. Ackerman

Cloud base height profiles measured with laser ceilometer are studied using multifractal approach. The irregular structure of the signals is a benchmark for nonlinear dynamical processes. A hierarchy of generalized dimensions determines the intermittency of the signal. The multi-affine properties are described by the $h(γ)$ function.

H. Sakaguchi

A random multiplicative process with additive noise is described by a Langevin equation. We show that the fluctuation-dissipation relation is satisfied in the Langevin model, if the noise strength is not so strong.

Beom Jun Kim, H. Hong, Petter Holme, Gun Sang Jeon

The phase transition in the XY model on one-dimensional small-world networks is investigated by means of Monte-Carlo simulations. It is found that long-range order is present at finite temperatures, even for very small values of the rewiring probability, suggesting a finite-temperature transition for any nonzero rewiring probability. Nature of the phase tran

W. Selke, F. Szalma, J. S. Hager

Fluctuations of isolated and pairs of ascending steps of monoatomic height are studied in the framework of SOS models, using mainly Monte Carlo techniques. Below the roughening transistion of the surface, the profiles of long steps show the same scaling features for terrace and surface diffusion. For a pair of short steps, their separation distance is found

Thomas Prellberg, Aleksander L. Owczarek

The coil-globule transition of an isolated polymer has been well established to be a second-order phase transition described by a standard tricritical O(0) field theory. We present Monte-Carlo simulations of interacting self-avoiding walks and interacting self-avoiding trails in four dimensions which provide compelling evidence that the approach to this (tri

Joonhyun Yeo, M. A. Moore

We study the thermodynamics of a model of pancake vortices in layered superconductors. The model is based on the effective pair potential for the pancake vortices derived from the London approximation of a version of the Lawrence-Doniach model which is valid for extreme type-II superconductors. Using the hypernetted-chain (HNC) approximation, we find that th

Subir Sachdev, Kwon Park

We explore the ground states and quantum phase transitions of two-dimensional, spin S=1/2, antiferromagnets by generalizing lattice models and duality transforms introduced by Sachdev and Jalabert (Mod. Phys. Lett. B 4, 1043 (1990), http://onsager.physics.yale.edu/p32.pdf). The `minimal' model for square lattice antiferromagnets is a lattice discretizati

W. N. Brandt, D. M. Alexander, A. E. Hornschemeier, G. P. Garmire

An extremely deep X-ray survey (about 1 Ms) of the Hubble Deep Field North and its environs (about 450 arcmin^2) has been performed with the Advanced CCD Imaging Spectrometer on board the Chandra X-ray Observatory. This is one of the two deepest X-ray surveys ever performed; for point sources near the aim point it reaches 0.5-2.0 keV and 2-8 keV flux limits

Daniel Kasen, David Branch, E. Baron, David Jeffery

We show that the shape of P-Cygni line profiles of photospheric phase supernova can be analytically inverted to extract both the optical depth and source function of the line -- i.e. all the physical content of the model for the case when the Sobolev approximation is valid. Under various simplifying assumptions, we derive formulae that give S(r) and tau(r) i

Sean O'Neill, Angela V. Olinto, Pasquale Blasi

We consider the effects of the Galactic magnetic field on the propagation of ultra high energy cosmic rays (UHECRs). By employing two methods of trajectory simulation, we investigate the possibility that UHECRs are produced within the Galaxy with paths strongly influenced by the Galactic magnetic field. Such trajectories have the potential to reconcile the e

D. Grupe

X-ray transience is the most extreme form of variability observed in AGN or normal in-active galaxies. While factors of 2-3 on timescales of days to years are quite commen among AGN, X-ray transients appear only once and vanish from the X-ray sky years later. The ROSAT All-Sky Survey was the tool to discover these sources. X-ray transience in AGN or galaxies

Karen T. Lewis, David N. Burrows, John P. Hughes, Patrick Slane

We present new results from a 40.8 ks Chandra ACIS observation of the young supernova remnant (SNR) N103B located in the Large Magellanic Cloud. The high resolution Chandra image reveals structure at the sub-arcsecond level, including several bright knots and filaments. Narrow-band imaging and spatially resolved spectroscopy reveal dramatic spectral variatio

Simone Daflon, Katia Cunha, Keith Butler, Verne V. Smith

Elemental abundances of carbon, nitrogen, oxygen, magnesium, aluminum, and silicon are presented for a sample of twelve rapidly rotating OB star (v sin i > 60 km s^-1) members of the Cep OB2, Cyg OB3 and Cyg OB7 associations. The abundances are derived from spectrum synthesis, using both LTE and non-LTE calculations. As found in almost all previous studies o

M. Guainazzi, T. Oosterbroek

The PDS experiment onboard BeppoSAX is the most sensitive instrument ever above 10 keV. Preliminary results on the complete catalogue of AGN observed with it are presented in this paper.

P. R. Vishwanath

Monte Carlo calculations have been done to study the possibilities of using different spatial distributions, local fluctuations and the number of Cerenkov photons in gamma ray showers to increase the sensitivity of the PACT experiment. After matching the trigger rates in data with the predictions of simulations, the energy threshold of the array for gamma ra

R. Cowsik, P. N. Bhat, V. R. Chitnis, B. S. Acharya

Recently an Indian Astronomical Observatory has been set up at Hanle (32$^\circ$ 46$^\prime$ 46$^{\prime\prime}$ N, 78$^\circ$ 57$^\prime$ 51$^{\prime\prime}$ E, 4515m amsl) situated in the high altitude cold desert in the Himalayas. The Observatory has 2-m aperture optical-infrared telescope, recently built by the Indian Institute of Astrophysics. We have c

P. N. Bhat, V. R. Chitnis

In atmospheric Čerenkov technique $γ-$rays are detected against abundant background produced by hadronic showers. In order to improve signal to noise ratio of the experiment, it is necessary to reject a significant fraction of hadronic showers. The temporal and spectral differences, the lateral distributions and density fluctuations of Čerenkov photons gener

V. R. Chitnis, P. N. Bhat

Wavefront sampling experiments record arrival times of Čerenkov photons with high precision at various locations in Čerenkov pool using a distributed array of telescopes. It was shown earlier that this photon front can be fitted with a spherical surface traveling at a speed of light and originating from a single point on the shower axis. Radius of curvature

M. J. Page

We investigate the relationship between the present day optical luminosity function of galaxies and the X-ray luminosity function of Seyfert 1s to determine the fraction of galaxies which host Seyfert 1 nuclei and their Eddington ratios. The local type 1 AGN X-ray luminosity function is well reproduced if ~ 1% of all galaxies are type 1 Seyferts which have E

Sabine Schindler

The effects of cluster mergers on the metal enrichment of the intra-cluster gas in clusters of galaxies are reviewed. Mergers can influence the metal production as well as the gas ejection processes, which transport the gas from the galaxy potential wells into the intra-cluster gas. Several processes are discussed: ram-pressure stripping, galactic winds and

Rick Edelson, T. J. Turner, Ken Pounds, Simon Vaughan

The bright, soft X-ray spectrum Seyfert 1 galaxies Ark 564 and Ton S180 were monitored for 35 days and 12 days with ASCA and RXTE (and EUVE for Ton S180). The short time scale (hours-days) variability patterns were very similar across energy bands, with no evidence of lags between any of the energy bands studied. The fractional variability amplitude was almo

Ian I. Kogan

This is a talk presented at XXXVIth Rencontres de Moriond, ElectroWeak Interactions and Unified Theories, March 2001. A short review of modern status of multigravity, i.e. modification of gravity at both short and large distances is given.

Eric Braaten, Yu Jia, Thomas Mehen

This paper explores a new mechanism for B production in which a b quark combines with a light parton from the hard-scattering process before hadronizing into the B hadron. This recombination mechanism can be calculated within perturbative QCD up to a few nonperturbative constants. Though suppressed at large transverse momentum by a factor Lambda_QCD m_b/p_t^

G. Barenboim, L. Borissov, J. Lykken, A. Yu Smirnov

CPT violation has the potential to explain all three existing neutrino anomalies without enlarging the neutrino sector. CPT violation in the Dirac mass terms of the three neutrino flavors preserves Lorentz invariance, but generates independent masses for neutrinos and antineutrinos. This specific signature is strongly motivated by braneworld scenarios with e

Eric Braaten, H. -W. Hammer, Thomas Mehen

We study a dilute Bose gas of atoms whose scattering length a is large compared to the range of their interaction. We calculate the energy density of the homogeneous Bose-Einstein condensate to second order in the low-density expansion, expressing it in terms of a and a second parameter Lambda_* that determines the low-energy observables in the 3-body sector

L. -A. Wu, M. S. Byrd, D. A. Lidar

We propose a polynomial-time algorithm for simulation of the class of pairing Hamiltonians, e.g., the BCS Hamiltonian, on an NMR quantum computer. The algorithm adiabatically finds the low-lying spectrum in the vicinity of the gap between ground and first excited states, and provides a test of the applicability of the BCS Hamiltonian to mesoscopic supercondu

C. S. Lam

The characteristics and phenomenology of neutrino oscillation in extra dimensions are briefly reviewed

Steven Corley, David A. Lowe

As a step toward constructing realistic brane world models in string theory, we consider the interactions of a pair of non-BPS branes. We construct a dyonic generalization of the non-BPS branes first constructed by Bergman, Gaberdiel and Sen as orbifolds of D-branes on $T^4/\BZ_2$. The force between a dyonic brane and an electric brane is computed and is fou

G. Baskaran

Doped divalent hexaborides such as $Sr_{1-x}La_xB_6$ exhibit high \tc ferromagnetism. We isolate a degenerate pair of $2p$-orbitals of boron with two valence electrons, invoke electron correlation and Hund coupling, to suggest that the undoped state is better viewed as a spin-1 Mott insulator; it is predicted to be a type of 3d Haldane gap phase with a spin

J. Ashkenazi

The quasiparticles of the high-T_c cuprates are found to consist of: polaron-like "stripons" carrying charge, and associated primarily with large-U orbitals in stripe-like inhomogeneities; "quasielectrons" carrying charge and spin, and associated with hybridized small-U and large-U orbitals; and "svivons" carrying spin and lattice dis

Borut Bajc, Ilia Gogoladze, Ramon Guevara, Goran Senjanovic

We discuss a supersymmetric SU(6) grand unified theory with the GUT flat direction being lifted by soft supersymmetry breaking, and the doublet-triplet splitting being achieved with Higgs as a pseudo-Goldstone boson. The theory offers a simple solution to the false vacuum and monopole problems.

P. H. Chavanis

We complete the existing literature on the structure and stability of polytropic gas spheres reported in the classical monograph of Chandrasekhar (1942). For isolated polytropes with index $1<n<5$, we provide a new, alternative, proof that the onset of instability occurs for $n=3$ and we express the perturbation profiles of density and velocity at the point

Maurice H. P. M. van Putten

Numerical relativity describes a discrete initial value problem for general relativity. A choice of gauge involves slicing space-time into space-like hypersurfaces. This introduces past and future gauge relative to the hypersurface of present time. Here, we propose solving the discretized Einstein equations with a choice of gauge in the future and a dynamica

O. Dauchot, F. Lechenault, C. Gasquet, F. Daviaud

We demonstrate the feasibility of studying dunes in a laboratory experiment. It is shown that an initial sand pile, under a wind flow carrying sand, flattens and gets a shape recalling barchan dunes. An evolution law is proposed for the profile and the summit of the dune. The dune dynamics is shown to be shape invariant. The invariant shape, the ``dune funct

L. Degiovanni, G. Magnano

We show that for a class of dynamical systems, Hamiltonian with respect to three distinct Poisson brackets (P_0, P_1, P_2), separation coordinates are provided by the common roots of a set of bivariate polynomials. These polynomials, which generalise those considered by E. Sklyanin in his algebro-geometric approach, are obtained from the knowledge of: (i) a

Hartmuth Arenhoevel, Michael Schwamb

We propose a new method for the construction of a consistent meson exchange current in $r$-space for the spin-isospin dependent central and tensor part of phenomenological nucleon-nucleon potentials by using a Laplace transformation, which allows the representation by a finite number of Yukawa functions. This method is applied to the Paris and the recent Arg

Kikuo Harigaya, Naoki Kawatsu, Toshiaki Enoki

Nanographite systems, where graphene sheets of the orders of the nanometer size are stacked, show novel magnetic properties, such as, spin-glass like behaviors, and the change of ESR line widths while gas adsorptions. Recently, it has been found that magnetic moments decrease with the decrease of the interlayer distance while water molecules are attached phy

F. Krzakala, M. Mezard, M. Mueller

We characterize the low temperature phase of a simple model for RNA secondary structures by determining the typical energy scale E(l) of excitations involving l bases. At zero temperature, we find a scaling law E(l) \sim l^θwith θ\approx 0.23, and this same scaling holds at low enough temperatures. Above a critical temperature, there is a different phase cha

M. Governale, D. Boese, U. Zuelicke, C. Schroll

We show how momentum-resolved tunneling between parallel electron wave guides can be used to observe and exploit lifting of spin degeneracy due to Rashba spin-orbit coupling. A device is proposed that achieves spin filtering without using ferromagnets or the Zeeman effect.

P. Huber, J. W. F. Valle

We consider the potential of a generic neutrino factory (NUFACT) in probing non-standard neutrino-matter interactions (NSI). We find that the sensitivity to flavour-changing (FC) NSI can be substantially improved with respect to present atmospheric neutrino data, especially at energies higher than approximately 50 GeV, where the effect of the tau mass is sma

M. V. Garzelli, C. Giunti

We present the results of a Bayesian analysis of solar neutrino data in terms of nu_e->nu_{mu,tau} and nu_e->nu_s oscillations, where nu_s is a sterile neutrino. We perform a Rates Analysis of the rates of solar neutrino experiments, including the first SNO CC result, and spectral data of the CHOOZ experiment, and a Global Analysis that takes into account al

Juha-Pekka Pellonpaa

We study the mathematical structure of covariant phase observables. Such an observable can alternatively be expressed as a phase matrix, as a sequence of unit vectors, as a sequence of phase states, or as an equivalent class of covariant trace-preserving operations. Covariant generalized operator measures are defined by structure matrices which form a W*-alg

Alok Kumar, Rashmi Rekha Nayak, Kamal Lochan Panigrahi

We show the existence of non-threshold bound states of (p, q) string networks and D3-branes, preserving 1/4 of the full type IIB supersymmetry, interpreted as string networks dissolved in D3-branes. We also write down the expression for the mass density of the system and discuss the extension of the construction to other Dp-branes. Differences in our constru

L. S. Georgiev

We review a recent development in the theoretical understanding of the nu=5/2 quantum Hall plateau and propose a new conformal field theory, slightly different from the Moore-Read one, to describe another universality class relevant for this plateau. The ground state is still given by the Pfaffian and is completely polarized, however, the elementary quasihol

Lev N. Shchur, Oleg A. Vasilyev

We present a new way of probing the universality class of the site-diluted two-dimensional Ising model. We analyse Monte Carlo data for the magnetic susceptibility, introducing a new fitting procedure in the critical region applicable even for a single sample with quenched disorder. This gives us the possibility to fit simultaneously the critical exponent, t

Shin&#39;ichi Nojiri, Sergei D. Odintsov, Sachiko Ogushi

General model of multidimensional $R^2$-gravity including Riemann tensor square term (non-zero $c$ case) is considered. The number of brane-worlds in such model is constructed (mainly in five dimensions) and their properties are discussed. Thermodynamics of S-AdS BH (with boundary) is presented when perturbation on $c$ is used. The entropy, free energy and e

V. V. Flambaum, F. M. Izrailev

We study the time evolution of occupation numbers for interacting Fermi-particles in the situation when exact compound states are &#34;chaotic&#34;. This situation is generic for highly excited many-particles states in heavy nuclei, complex atoms, quantum dots, spin systems and quantum computer models. Numerical data show perfect agreement with a simple theo

John Calsamiglia

I give a first characterization of the class of generalized measurements that can be exactly realized on a pair of qudits encoded in indistinguishable particles, by using only linear elements and particle detectors. Two immediate results follow from this characterization. (i) The Schmidt number of each POVM element cannot exceed the number of initial particl

K. Inoue, M. Ohya, I. V. Volovich

Quantum baker`s map is a model of chaotic system. We study quantum dynamics for the quantum baker&#39;s map. We use the Schack and Caves symbolic description of the quantum baker`s map. We find an exact expression for the expectation value of the time dependent position operator. A relation between quantum and classical trajectories is investigated. Breakdow

Edward B. Fel&#39;dman, Serge Lacelle

A quantum information processing device, based on bulk solid state NMR of the quasi-one dimensional material hydroxyapatite, is proposed following the magnetic resonance force microscopy work of Yamamoto et al (quant-ph/0009122). In a macroscopic sample of hydroxyapatite, our solid state NMR model yields a limit of 10^8 qubits imposed by physics, while devel

David A. Meyer, Nolan R. Wallach

We define a polynomial measure of multiparticle entanglement which is scalable, i.e., which applies to any number of spin-1/2 particles. By evaluating it for three particle states, for eigenstates of the one dimensional Heisenberg antiferromagnet and on quantum error correcting code subspaces, we illustrate the extent to which it quantifies global entangleme

C. Wellard, L. C. L. Hollenberg, H. C. Pauli

The method of iterated resolvents is used to obtain an effective Hamiltonian for neighbouring qubits in the Kane solid state quantum computer. In contrast to the adiabatic gate processes inherent in the Kane proposal we show that free evolution of the qubit-qubit system, as generated by this effective Hamiltonian, combined with single qubit operations, is su

R. Bijker, A. Frank

Random interactions are used to investigate to what extent the low-lying behavior of even-even nuclei depend on particular nucleon-nucleon interactions. The surprising results that were obtained for the interacting boson model, i.e. the dominance of ground states with L=0 and the occurrence of both vibrational and rotational structure, are interpreted and ex

Yaoming Shi, W. M. McClain, J. E. Hearst

We introduce a spectral parameter into the geometrically exact Hamiltonian equations for the elastic rod in a way that creates a Lax pair. This assures integrability and permits application of the inverse scattering transform solution method. If the method can be carried through, the solution of the original problem is recovered by setting the spectral param