May 1998 arXiv papers — page 6

A. Pineda, J. Soto

We discuss in detail potential NRQED (pNRQED), a previously proposed effective field theory for ultrasoft photons. The pNRQED lagrangian for the equal mass case is presented and it is shown that it correctly reproduces the positronium spectrum at order $mα^5$. The pNRQED lagrangian for the unequal mass case is also presented at the same order. Dimensional re

Claus Wilke, Thomas Martinetz

A generalization of the coherent-noise models [M. E. J. Newman and K. Sneppen, Phys. Rev. E{\bf54}, 6226 (1996)] is presented where the agents in the model are subjected to a multitude of stresses, generated in a hierarchy of different contexts. The hierarchy is realized as a Cayley-tree. Two different ways of stress propagation in the tree are considered. I

Patricia Ball, V. M. Braun

We present the first complete results for the semileptonic and rare radiative form factors of B-mesons weak decay into a light vector-meson (rho, omega, K*, phi) in the light-cone sum-rule approach. The calculation includes radiative corrections, higher-twist corrections and SU(3)-breaking effects. The theoretical uncertainty is investigated in detail. A sim

R. Stompor, G. Efstathiou

Gravitational lensing, caused by matter perturbations along the line-of-sight to the last scattering surface, can modify the shape of the cosmic microwave background (CMB) anisotropy power spectrum. We discuss the detectability of lensing distortions to the temperature, polarisation and temperature-polarisation cross-correlation power spectra and we analyse

P. D. Olmsted, O. Radulescu, C. -Y. D. Lu

We study the Johnson-Segalman (JS) model as a paradigm for some complex fluids which are observed to phase separate, or ``shear-band'' in flow. We analyze the behavior of this model in cylindrical Couette flow and demonstrate the history dependence inherent in the local JS model. We add a simple gradient term to the stress dynamics and demonstrate ho

R. Manvelyan, A. Melikyan, R. Mkrtchyan

The 12d supersymmetry algebra is considered, and classification of BPS states for some canonical form of second-rank central charge is given. It is shown, that possible fractions of survived supersymmetry can be 1/16, 1/8, 3/16, 1/4, 5/16 and 1/2, the values 3/8, 7/16 cannot be achieved in this way. The consideration of a special case of non-zero sixth-rank

Kwan-tai Leung, Jian-Sheng Wang

We study the standard three-dimensional driven diffusive system on a simple cubic lattice where particle jumps along a given lattice direction are biased by an infinitely strong field, while those along other directions follow the usual Kawasaki dynamics. Our goal is to determine which of the several existing theories for critical behavior is valid. We analy

T. Osada, M. Maruyama, F. Takagi

A new statistical model for multiparticle production in $e^+e^-$ annihilation is proposed based on the idea of the longitudinal phase space with limited transverse momentum. The longitudinal rapidity space is divided into cells of equal size in order to take into account the Bose-Einstein correlations(BEC) with a finite correlation length $δy$. The maximum e

Beatrice Paladini, James C. Sexton

The asymptotic expansion of the massive scalar field propagator on a n-dimensional lattice is derived. The method used is based on the evaluation of the asymptotic expansion of the modified Bessel function $I_ν(ν^{2} β)$ as the order $ν$ grows to infinity.

Sergei Yu. Sakovich

A (2+1)-dimensional perturbed KdV equation, recently introduced by W.X. Ma and B. Fuchssteiner, is proven to pass the Painlevé test for integrability well, and its 4$\times $4 Lax pair with two spectral parameters is found. The results show that the Painlevé classification of coupled KdV equations by A. Karasu should be revised.

George Triantaphyllou

Dynamical mass generation in a three-dimensional version of finite-temperature QED is studied with the help of Schwinger-Dyson equations in the real-time formalism. We go beyond the bare-vertex approximation and include wave-function renormalization effects. This introduces a system of two integral equations which are solved numerically. In order to increase

Christoph P. Hofmann

Nonrelativistic systems exhibiting collective magnetic behavior are analyzed in the framework of effective Lagrangians. The method, formulating the dynamics in terms of Goldstone bosons, allows to investigate the consequences of spontaneous symmetry breaking from a unified point of view. Low energy theorems concerning spin-wave scattering in ferro- and antif

R. Conte, M. Musette

We investigate the question of finding discrete Lax pairs for the six discrete Painlevé equations (Pn). The choice we make is to discretize the pairs of Garnier, once converted to matricial form.

Chi-Sheng Niu, Robert B. Griffiths

A quantum copying machine producing two (in general non-identical) copies of an arbitrary input state of a two-dimensional Hilbert space (qubit) is studied using a quality measure based on distinguishability of states, rather than fidelity. The problem of producing optimal copies is investigated with the help of a Bloch sphere representation, and shown to ha

Pawel Horodecki, Ryszard Horodecki, Michal Horodecki

We provide some new properties of entanglement of formation. In particular, we obtain an additive lower bound for entanglement of formation. Subsequently we develop the concept of local orthogonality of ensembles which leads to the mixed states with distillable entanglement equal to entanglement of formation. Then we consider thermodynamical analogies within

W. T. Buttler, R. J. Hughes, P. G. Kwiat, S. K. Lamoreaux

A working free-space quantum key distribution (QKD) system has been developed and tested over an outdoor optical path of ~1 km at Los Alamos National Laboratory under nighttime conditions. Results show that QKD can provide secure real-time key distribution between parties who have a need to communicate secretly. Finally, we examine the feasibility of surface

J. A. Jones, R. H. Hansen, M. Mosca

We demonstrate how NMR can in principle be used to implement all the elements required to build quantum computers, and briefly discuss the potential applications of insights from quantum logic to the development of novel pulse sequences with applications in more conventional NMR experiments.

J. A. Jones, M. Mosca, R. H. Hansen

We demonstrate an implementation of a quantum search algorithm on a two qubit NMR quantum computer based on cytosine.

W. A. Majewski

We shortly review the progress in the domain of deterministic chaos for quantum dynamical systems. With the appropriately extended definition of quantum Lyapunov exponent we analyze various quantum dynamical maps. It is argued that, within Quantum Mechanics, irregular evolution for properly chosen observables can coexist with regular and predictable evolutio

A. E. Allahverdyan, D. B. Saakian

It is well known that quantum theory forbids the exact copying of an unknown quantum state. Therefore in broadcasting of classical information by a quantum channel an additional contribution to the error in the decoding is expected. We consider the optimal copying transformation which is adapted to classical information transmission by two linearly independe

G. Hofer-Szabo, M. Redei, L. E. Szabo

It is shown that, given any finite set of pairs of random events in a Boolean algebra which are correlated with respect to a fixed probability measure on the algebra, the algebra can be extended in such a way that the extension contains events that can be regarded as common causes of the correlations in the sense of Reichenbach's definition of common cau

P. J. Dortmans, K. Amos, S. Karataglidis, J. Raynal

Nonlocal coordinate space optical potentials for the scattering of 65 MeV protons from nuclei ranging in mass from 6Li to 238U have been defined by folding a complex, medium dependent effective interaction with the density matrix elements of each target. The effective interaction is based upon solutions of the Lippmann--Schwinger and Brueckner--Bethe--Goldst

Florian Nill

Let A be a finite dimensional unital associative algebra over a field K, which is also equipped with a coassociative counital coalgebra structure (Δ,\eps). A is called a Weak Bialgebra if the coproduct Δis multiplicative. We do not require Δ(1) = 1 \otimes 1 nor multiplicativity of the counit \eps. Instead, we propose a new set of counit axioms, which are mo

Dan Edidin

The purpose of these notes is to give an introduction to Deligne-Mumford stacks and their moduli spaces, with emphasis on the moduli problem for curves. The paper has 4 sections. In section 1 we discuss the general problem of constructing a moduli "space" of curves. In section 2 we give an introduction to Deligne-Mumford stacks and their moduli space

Jonathan Fine

Although intersection homology lacks a ring structure, certain expressions (called uniform) in the intersection homology of an irreducible projective variety $X$ always give the same value, when computed via the decomposition theorem on any resolution $X_r\to X$. This paper uses uniform (and non-uniform) expressions to define what is believed to be the usual

Kieran G. O'Grady

In preprint alg-geom/9708009 we have constructed a (ten-dimensional) symplectic desingularization of the moduli space of rank-two torsion-free semistable sheaves on a $K3$, with trivial determinant and second Chern class equal to 4. In the present paper we prove that (every deformation of) this desingularization is a new irreducible symplectic variety. More

A. M. Perelomov, E. Ragoucy, P. Zaugg

Quantum integrable systems generalizing Calogero-Sutherland systems were introduced by Olshanetsky and Perelomov (1977). Recently, it was proved that for systems with trigonometric potential, the series in the product of two wave functions is a deformation of the Clebsch-Gordan series. This yields recursion relations for the wave functions of those systems.

C. P. Constantinidis, F. P. Devecchi, F. Toppan

Two-dimensional N=1,2 supersymmetric chiral models and their dual extensions are introduced and canonically quantized. Working within a superspace formalism, the non-manifest invariance under 2D-superPoincare' transformations is proven. The N=1,2 superVirasoro algebras are recovered as current algebras. The non-anomalous quantum invariances under 1D-supe

Cong-Feng Qiao, Feng Yuan, Kuang-Ta Chao

We investigate the SM Higgs decays into heavy quarkonia J/ψand Υin both color-singlet and color-octet mechanisms. It is found that in J/ψproduction the contribution through color-octet processes overwhelm that in color-singlet processes all the intermediate region M_Z<M_{H^0}<2 M_w and the fraction ratio is comparatively large, but in Υproduction the contrib

B. Borasoy, B. R. Holstein

The non-leptonic hyperon decays are analyzed up to one-loop order including all counterterms in the framework of heavy baryon chiral perturbation theory. We use the exchange of the spin-3/2 decuplet resonances as an indication of which low-energy constants contribute significantly to these investigated processes . We choose four independent decay amplitudes

S. Esposito, G. Mangano, G. Miele, O. Pisanti

We present a derivation of the medium dependent wave function renormalization for a spinor field in presence of a thermal bath. We show that, as already pointed out in literature, projector operators are not multiplicatively renormalized and the effect involves a non trivial spinor dependence, which disappears in the zero temperature covariant limit. The res

Marion Flanz, Emmanuel A. Paschos

We work out the thermodynamic equations for the decays and scatterings of heavy Majorana neutrinos including the constraints from unitarity. The Boltzmann equations depend on the CP asymmetry parameter which contains both, a self-energy and a vertex correction. At thermal equilibrium there is no net lepton asymmetry due to the CPT theorem and the unitarity c

A. Dedes, A. B. Lahanas, K. Tamvakis

We make a comparison of the predicted effective weak mixing angle, the Z-on resonance asymmetries and the W-boson mass to the LEP and SLD data at their present status. We find that the predicted MSSM values for the effective weak mixing angle are in agreement with the LEP+SLD average value for a ``heavy&#39;&#39; SUSY breaking scale while we observe an agree

D. Ebert, R. N. Faustov, V. O. Galkin

Exclusive semileptonic B meson decays to orbitally excited D mesons are investigated in the infinitely heavy quark limit in the framework of the relativistic quark model based on the quasipotential approach. The B\to D^{**}eνIsgur-Wise functions τ_{3/2}(w) and τ_{1/2}(w) are determined. It is found that the relativistic transformation of the meson wave funct

Helmut Satz

Using percolation theory, we derive a conceptual definition of deconfinement in terms of cluster formation. The result is readily applicable to infinite volume equilibrium matter as well as to finite size pre-equilibrium systems in nuclear collisions.

H. Jung, L. Joensson, H. Kuester

It has been found that recent results on forward jet production from deep inelastic scattering can neither be reproduced by models which are based on leading order alpha_s QCD matrix elements and parton showers nor by next-to-leading order calculations. The measurement of forward jet cross sections has been suggested as a promising probe of new small x dynam

S. Anderson

Using the CLEO II detector we have performed the first search for $CP$ violation in tau lepton decay. CP violation in lepton decay does not occur in the minimal standard model but can occur in extensions such as the multi-Higgs doublet model. It appears as a characteristic difference between the $τ^+$ and $τ^-$ decay angular distributions for the semi-lepton

Shigetaka Moriyama, Makoto Minowa, Toshio Namba, Yoshizumi Inoue

We have searched for axions which could be produced in the solar core by exploiting their conversion to X rays in a strong laboratory magnetic field. The signature of the solar axion is an increase in the rate of the X rays detected in a magnetic helioscope when the sun is within its acceptance. From the absence of such a signal we set a 95% confidence level

Bozhidar Z. Iliev

The equivalence principle is treated on a mathematically rigorous base on sufficiently general subsets of a differentiable manifold. This is carried out using the basis of derivations of the tensor algebra over that manifold. Necessary and/or sufficient conditions of existence, uniqueness, and holonomicity of these bases in which the components of the deriva

C. -J. Chien, V. Chandrasekhar

We have measured the transport properties of two mesoscopic hybrid loops composed of a normal-metal arm and a superconducting arm. The samples differed in the transmittance of the normal/superconducting interfaces. While the low transmittance sample showed monotonic behavior in the low temperature resistance, magnetoresistance and differential resistance, th

S. Misra, R. Gatt, T. Schmauder, Andrey V. Chubukov

We analyzed photoemssion data for several doping levels of the Bi_2Sr_2CaCu_2O_{8+x} compounds, ranging from overdoped to underdoped. We show that the high frequency part of the spectra near (0,π) can be described by Fermi liquid theory in the overdoped regime, but exhibits a non-Fermi liquid behavior in the underdoped regime. We further demonstrate that thi

Thomas Gramespacher, Markus Buttiker

New experiments that measure the low-frequency shot-noise spectrum at local tunneling contacts on mesoscopic structures are proposed. The current fluctuation spectrum at a single tunneling tip is determined by local partial densities of states. The current-correlation spectrum between two tunneling tips is sensitive to non-diagonal density of states elements

Ronald Dickman, Jafferson Kamphorst Leal da Silva

We determine the first through fourth moments of the order parameter, and various ratios, for several one- and two-dimensional models with absorbing-state phase transitions. We perform a detailed analysis of the system-size dependence of these ratios, and confirm that they are indeed universal for three models - the contact process, the A model, and the pair

Dirk Helbing

In the last decade, stochastic models have shown to be very useful for quantitative modelling of social processes. Here, a configurational master equation for the description of behavioral changes by pair interactions of individuals is developed. Three kinds of social pair interactions are distinguished: Avoidance processes, compromising processes, and imita

Philippe Jund, Remi Jullien

Using molecular dynamics calculations and the Voronoi tessellation, we study the evolution of the local structure of a soft-sphere glass versus temperature starting from the liquid phase at different quenching rates. This study is done for different sizes and for two different boundary conditions namely the usual cubic periodic boundary conditions and the is

Philippe Jund, Remi Jullien

We use molecular dynamics simulations and the Voronoi tessellation to study the geometrical modifications as a function of temperature in a model silica glass. The standard deviation of the cell volumes, which is a measure of the local density fluctuations, decreases with decreasing temperature, as if it would like to vanish at zero temperature. This evoluti

R. A. Klemm, G. Arnold, C. T. Rieck, K. Scharnberg

We calculate Ic(T) and Rn for both coherent and incoherent electron tunneling across a c-axis break junction between nu=s,d_x^2-y^2-wave superconducting half spaces, each with c-axis bandwidth 2J. Coherent quasiparticle tunneling only occurs for voltages V<2J/e, leading to difficulties in measuring Rn for underdoped samples. The coherent part of Ic(0) is ind

A. Misra, B. K. Chakrabarti

We report the results of mean field and the Monte Carlo study of the dynamic magnetization-reversal transition in the Ising model, brought about by the application of an external field pulse applied in opposition to the existing order before the application of the pulse. The transition occurs at a temperature T below the static critical temperature T_c witho

Torsten Strunz, Franz-Josef Elmer

The dynamical behavior of a weakly damped harmonic chain in a spatially periodic potential (Frenkel-Kontorova model) under the subject of an external force is investigated. We show that the chain can be in a spatio-temporally chaotic state called fluid-sliding state. This is proven by calculating correlation functions and Lyapunov spectra. An effective tempe

Torsten Strunz, Franz-Josef Elmer

The dynamical behavior of a harmonic chain in a spatially periodic potential (Frenkel-Kontorova model, discrete sine-Gordon equation) under the influence of an external force and a velocity proportional damping is investigated. We do this at zero temperature for long chains in a regime where inertia and damping as well as the nearest-neighbor interaction and

Alexei Vazquez, Oscar Sotolongo Costa, Carlos Antoranz

The theory of SOC, and related avalanche dynamics, is proposed as the origin of the ubiquitous nonexponential relaxation observed in complex systems. Introducing some scaling laws and relations we have obtained that the normalized relaxation function follows an stretched exponential decay and that the frequency spectrum follows a &#34;1/f&#34; noise. Moreove

Pablo Fernández, Andrea Dal Corso, Alfonso Baldereschi

We present a first-principles calculation of the electronic properties of crystalline silicon and gallium arsenide in a uniform electric field. Polarized Wannier-like functions which are confined in a finite region are obtained by minimizing a total-energy functional which depends explicitly on the macroscopic polarization of the solid. The polarization char

S. Nishimoto, Y. Ohta

The ground state of the one-dimensional dimerized $t$$-$$J$ model at quarter filling is studied by a Lanczos exact-diagonalization technique on small clusters. We calculate the charge gap, spin gap, binding energy, Tomonaga-Luttinger-liquid parameter, Drude weight, anomalous flux quantization, etc. We thereby show that the two types of dimerization, i.e., a

Ruben Weht, W. E. Pickett

Comprised of ferromagnetic edge-sharing CuO$_2$ chains that order in antialigned fashion at T$_N$=9 K, Li$_2$CuO$_2$ is found from local spin density calculations to display several surprising characteristics: (1) the ordered moment/f.u. of 0.92 $μ_B$ is the largest for any low dimensional cuprate system, in agreement with experiment, (2) 40% of this moment

C. S. O&#39;Hern, T. C. Lubensky

The sliding columnar phase is a new liquid-crystalline phase of matter composed of two-dimensional smectic lattices stacked one on top of the other. This phase is characterized by strong orientational but weak positional correlations between lattices in neighboring layers and a vanishing shear modulus for sliding lattices relative to each other. A simplified

C. Chandre, H. R. Jauslin, G. Benfatto

We construct an approximate renormalization scheme for Hamiltonian systems with two degrees of freedom. This scheme is a combination of Kolmogorov-Arnold-Moser (KAM) theory and renormalization-group techniques. It makes the connection between the approximate renormalization procedure derived by Escande and Doveil, and a systematic expansion of the transforma

Petr A. Braun, Daniel Braun, Fritz Haake

The master equation for a damped spin well known from the theory of superradiance, is written as a finite-difference equation and solved by a WKB-like method. The propagator thus obtained looks like the van Vleck propagator of a certain classical Hamiltonian system with one degree of freedom. A new interpretation is provided of the temporal broadening of ini

James Chiang

Temporal analyses of the prompt gamma-ray and X-ray light curves of gamma-ray bursts reveal a tendency for the burst pulse time scales to increase with decreasing energy. For an ensemble of BATSE bursts, Fenimore et al. (1995) show that the energy dependence of burst peak durations can be represented by $Δt \propto E^{-γ}$ with $γ\simeq 0.4$--0.45. This powe

Vicent Quilis, Jose Ma. Ibanez, Diego Saez

A rich galaxy cluster showing strong resemblance with the observed ones is simulated. Cold dark matter spectrum, Gaussian statistics, flat universe, and two components -- baryonic gas plus dark matter particles -- are considered. We have calculated the gravitational-wave output during the epoch of the fully nonlinear and nonsymmetric cluster evolution. The a

C. R. Eck, J. J. Cowan, D. Branch

Based upon the results of VLA observations, we report the detection of two unresolved radio sources that are coincident with the reported optical position of SN 1923A in M83. For the source closest to the SN position, the flux density was determined to be 0.30 +/- 0.05 mJy at 20 cm and 0.093 +/- 0.028 mJy at 6 cm. The flux density of the second nearby source

L. V. Verozub, E. Yu. Bannikova

Previously it was shown that gravitation theory allows the existance of supermassive stable compact configurations of the degenerated electronic gas (L.V.Verozub, Astr. Nacr. 317 (1996) 107) without events horizon. In the present paper the simplest model of such kind of objects in gas environment has been considered. It is shown that at the spherically symme

L. Mantegazza, E. Antonello

Accurate CCD observations of three Cepheids in the SMC were made with the purpose of confirming their nature of second overtone mode Cepheids. The stars were suspected pulsating in the second overtone mode owing to the unusual light curve and short period reported by Payne-Gaposchkin & Gaposchkin (1966). The analysis of the new data shows that for two stars

K. D. Kokkotas, N. Stergioulas

We present an analytic description of the $r$-mode instability in newly-born neutron stars, using the approximation of uniform density. Our computation is consistently accurate to second order in the angular velocity of the star. We obtain formulae for the growth-time of the instability due to gravitational-wave emission, for both current and mass multipole

J. K. Kotilainen

We present optical broad band B-I colour maps of a further sample of 10 Seyfert 2 galaxies. In these bands, the contribution from emission lines to the total flux is small, and hence the images predominantly trace the continuum distribution. As in our earlier colour maps of a sample of Seyferts type 1 and 2, we detect extended blue continuum components in th

J. K. Kotilainen, R. Falomo, R. Scarpa

We present the results of near-infrared H band (1.65 microns) imaging of 11 BL Lac objects with redshifts ranging from z = 0.05 to 0.9. We are able to clearly detect the host galaxy in seven low redshift (z<=0.24) BL Lacs, while the four unresolved BL Lacs have either high or unknown redshift. The galaxies hosting the low redshift BL Lacs are large (average

Jason X. Prochaska, Arthur M. Wolfe

We present new observational results on the kinematics of the damped lya systems. Our full sample is now comprised of 31 low-ion profiles and exhibits similar characteristics to the sample from Paper I. The primary exception is that the new distribution of velocity widths includes values out to a maximum of nearly 300 km/s, approx 100 km/s greater than the p

Leo Radzihovsky, John Toner

We show that a normal (single particle) current density $J_x$ {\em transverse} to the ordering wavevector $2k_F{\bf\hat{z}}$ of a charge density wave (CDW) has dramatic effects both above and {\em below} the CDW depinning transition. It exponentially (in $J_x$) enhances CDW correlations, and exponentially suppresses the longitudinal depinning field. The inte

W. Mück, K. S. Viswanathan

We use the AdS/CFT correspondence to calculate CFT correlation functions of vector and spinor fields. The connection between the AdS and boundary fields is properly treated via a Dirichlet boundary value problem.

Martin Schaden

I construct a Lattice Gauge Theory (LGT) with discrete Z_2 structure group and an equivariant BRST symmetry that is physically equivalent to the standard SU(2)-LGT. The measure of this Z_2-LGT is invariant under all the discrete symmetries of the lattice and its partition function does not vanish. The Topological Lattice Theories (TLT) that localize on the m

Jan von Delft, Herbert Schoeller

This tutorial gives an elementary and self-contained review of abelian bosonization in 1 dimension in a system of finite size $L$, following and simplifying Haldane&#39;s constructive approach. As a non-trivial application, we rigorously resolve (following Furusaki) a recent controversy regarding the tunneling density of states, $ρ_{dos} (ω)$, at the site of

Kentaro Hori

We study the Type IIA limit of the M theory fivebrane configuration corresponding to N=1 supersymmetric QCD with massless quarks. We identify the effective gauge coupling constant that fits with Novikov-Shifman-Veinshtein-Zakharov exact beta function. We find two different Type IIA limits that correspond to the electric and magnetic descriptions of SQCD, as

Ruben Flores-Mendieta, Elizabeth Jenkins, Aneesh V. Manohar

Flavor SU(3) symmetry breaking in the hyperon semileptonic decay form-factors is analyzed using the 1/N expansion. A detailed comparison with experimental data shows that corrections to f_1 are approximately 10%, which agrees with theoretical expectations. Corrections to g_1 are compatible with first-order symmetry breaking. A fit to the experimental data al

Kentaro Hori

We derive some consistency conditions for fivebrane in M theory on R^5/Z_2 orbifold from the quantization law for the antisymmetric tensor field. We construct consistent fivebrane configurations in R^5/Z_2 type orbifold that exhibit the correct low energy dynamics of N=2 SQCD in four dimensions with symplectic and orthogonal gauge groups. This leads us to pr

Steven S. Gubser, Akikazu Hashimoto

We consider a minimal scalar in the presence of a three-brane in ten dimensions. The linearized equation of motion, which is just the wave equation in the three-brane metric, can be solved in terms of associated Mathieu functions. An exact expression for the reflection and absorption probabilities can be obtained in terms of the characteristic exponent of Ma

J. J. Halliwell

For a system consisting of a large collection of particles, a set of variables that will generally become effectively classical are the local densities (number, momentum, energy). That is, in the context of the decoherent histories approach to quantum theory, it is expected that histories of these variables will be approximately decoherent, and that their pr

A. P. Billyard, A. A. Coley, R. J. van den Hoogen

We study the stability of cosmological scaling solutions within the class of spatially homogeneous cosmological models with a perfect fluid subject to the equation of state p_gamma=(gamma-1) rho_gamma (where gamma is a constant satisfying 0 < gamma < 2) and a scalar field with an exponential potential. The scaling solutions, which are spatially flat isotropi

Uwe R. Fischer

The quantum tunnelling and nucleation theory of vortices in helium II is reviewed. Arguments are given that the only reliable method to calculate tunnelling probabilities in this highly correlated, strongly interacting many-body system is the semiclassical, large scale approach for evaluation of the tunnelling exponent, which does not make any assumptions ab

Eric R. Bittner, D. S. Kosov

This paper describes a method to do ab initio molecular dynamics in electronically excited systems within the random phase approximation (RPA). Using a dynamical variational treatment of the RPA frequency, which corresponds to the electronic excitation energy of the system, we derive coupled equations of motion for the RPA amplitudes, the single particle orb

Masahisa Tsuchiizu, Yoshikazu Suzumura

By applying renormalization group method to the bosonized Hamiltonian of two-coupled chains with repulsive intrachain interaction, we have examined a role of backward scattering with a spin-anisotropy which competes with interchain hopping. From calculation of a dominant state in the limit of low energy, it is found that superconducting state moves into spin

R. Jakob, D. Boer, P. J. Mulders

We discuss various azimuthal asymmetries in semi-inclusive DIS and e^+e^- ==> h1 h2 X which involve chiral odd quantities like the transversity distribution h_1 and a fragmentation function H_1^\perp. For the fragmentation described by H_1^\perp azimuthal angular dependence has to be measured, but no polarization vector of a final state hadron. We present fi

Chang Chao-Hsi, Han Liang, Jiang Yi, Li Xue-Qian

The CP-violating effects are studied in the electron-positron annihilation to produce $t\bar{t}$ pair within the Model-III of the two-Higgs-doublet extensions, which allows flavor changing neutral currents via Higgs exchanges. Complete analytical expressions for the form factors of the top quark electric and weak dipole moment induced in the framework of the

Andrei A. Kapaev

All possible 1-parametric classical and transcendent degenerated solutions of the fourth Painleve equation with the corresponding connection formulae of the asymptotic parameters are described.

Wojciech H. Zurek

The roles of decoherence and environment-induced superselection in the emergence of the classical from the quantum substrate are described. The stability of correlations between the einselected quantum pointer states and the environment allows them to exist almost as objectively as classical states were once thought to exist: There are ways of finding out wh

A. Bohm, N. L. Harshman

After a review of the arrows of time, we describe the possibilities of a time-asymmetry in quantum theory. Whereas Hilbert space quantum mechanics is time-symmetric, the rigged Hilbert space formulation, which arose from Dirac&#39;s bra-ket formalism, allows the choice of asymmetric boundary conditions analogous to the retarded solutions of the Maxwell equat

J. Oppenheim, B. Reznik, W. G. Unruh

Using various model clocks it has been shown that the time-of-arrival cannot be measured more accurately than 1/E where E is the kinetic energy of a free particle. However, this result has never been proved. In this paper, we show that a violation of the above limitation for the transit-time, implies a violation of the Heisenberg uncertainty relation.

V. Velazquez, J. G. Hirsch, Y. Sun

The Projected Shell Model is a shell model theory built up over a deformed BCS mean field. Ground state and excited bands in even-even nuclei are obtained through diagonalization of a pairing plus quadrupole Hamiltonian in an angular momentum projected 0-, 2-, and 4-quasiparticle basis. The residual quadrupole-quadrupole interaction strength is fixed self-co

J. Chizma, G. Karl, V. Novikov

We discuss effects in beta decays at very low beta energies, of the order of the kinetic energies of atomic electrons. As the beta energy is lowered the atomic response changes from sudden to adiabatic. As a consequence, the beta decay rate increases slightly and the ejection of atomic electrons (shake off) and subsequent production of X rays is turned off.

D. J. Rowe, C. Bahri, W. Wijesundera

We consider a many-fermion model which exhibits a transition from a superconducting to a rotational phase with variation of a parameter in its Hamiltonian. The model has analytical solutions in its two limits due to the presence of dynamical symmetries. However, the symmetries are basically incompatible with one another; no simple solution exists in intermed

Saeed Zakeri

Motivated by the work of Douady, Ghys, Herman and Shishikura on Siegel quadratic polynomials, we study the one-dimensional slice of the cubic polynomials which have a fixed Siegel disk of rotation number theta, with theta being a given irrational number of Brjuno type. Our main goal is to prove that when theta is of bounded type, the boundary of the Siegel d

Walter D. Neumann, Paul Norbury

It has been proved several times in the literature that a polynomial map from $C^2$ to $C$ with irreducible rational fibers cannot be a component of a counterexample to the Jacobian Conjecture. This note points out that this result is empty: it is implicit in 1980 work of Miyanish and Sugie that such a polynomial is equivalent to $f(x,y)=x$ by a polynomial a

Mirjam Cvetic, Finn Larsen

We show that a class of four-dimensional rotating black holes allow five-dimensional embeddings as black rotating strings. Their near-horizon geometry factorizes locally as a product of the three-dimensional anti-deSitter space-time and a two-dimensional sphere (AdS_3 x S^2), with angular momentum encoded in the global space-time structure. Following the obs

A. V. Manohar

The Wess-Zumino term is constructed for supersymmetric QCD with two colors and flavors, and is shown to correctly reproduce the anomalous Ward identities. Supersymmetric QCD is also shown not to have topologically stable skyrmion solutions because of baryon flat directions, which allow them to unwind. The generalization of these results to other supersymmetr

J. L. F. Barbon, E. Rabinovici

We study the dimensionality manifested in the AdS/CFT correspondence. We show that the dimensionality as expressed by the high temperature behavior of a system has a holographic nature also at the quantum level. The emergence of the AdS black hole as a master field at high temperature leads to the screening of the extra dimensions in its excluded volume.

Amihay Hanany, Angel M. Uranga

Brane Box Models of intersecting NS and D5 branes are mapped to D3 branes at C^3/Gamma orbifold singularities and vise versa, in a setup which gives rise to N=1 supersymmetric gauge theories in four dimensions. The Brane Box Models are constructed on a two-torus. The map is interpreted as T-duality along the two directions of the torus. Some Brane Box Models

Lewis H. Ryder, Ilya L. Shapiro

We explore the Dirac equation in external electromagnetic and torsion fields. Motivated by the previous study of quantum field theory in an external torsion field, we include a nonminimal interaction of the spinor field with torsion. As a consequence, the torsion axial vector and the electromagnetic potential enter the action in a similar form. The existence

Dmitri Diakonov

We study the gauge-invariant gaussian ansatz for the vacuum wave functional and show that it potentially possesses many desirable features of the Yang--Mills theory, like asymptotic freedom, mass generation through the transmutation of dimensions and a linear potential between static quarks. We point out that these (and other) features can be studied in a sy

Seungjoon Hyun, Youngjai Kiem

Via supergravity, we argue that the infinite Lorentz boost along the M theory circle a la Seiberg toward the DLCQ M theory compactified on a p-torus (p<5) implies the holographic description of the microscopic theory. This argument lets us identify the background geometries of DLCQ $M$ theory on a p-torus; for p=0 (p=1), the background geometry turns out to

Romuald A. Janik, Jacek Wosiek

We present our recent results on the odderon intercept in perturbative QCD, obtained through the solution of the Baxter equation and investigation of the spectrum of the relevant constant of motion.

Gerald Cleaver, Mirjam Cvetic, Jose R. Espinosa, Lisa Everett

In quasi-realistic string models that contain an anomalous U(1) the non-zero Fayet-Iliopoulos term triggers the shifting of the original vacuum to a new one along some flat direction, so that SUSY is preserved but the gauge group is partially broken. The phenomenological study of these models thus requires as a first step the mapping of the space of flat dir

M. Graesser

Two models which generate the supersymmetric Grand Unification Scale from the strong dynamics of an additional gauge group are presented. The particle content is chosen such that this group confines with chiral symmetry breaking. Fields that are usually introduced to break the Grand Unified group appear instead as composite degrees of freedom and can acquire