March 1997 arXiv papers — page 8

Jian Wang, Qingrong Zheng, Hong Guo

To apply the scattering approach for the problem of AC transport through coherent quantum conductors, various partial density of states must be evaluated. If the global partial density of states (GPDOS) is calculated externally using the energy derivatives of the scattering matrix, the results are not precise unless the conductor has a large scattering volum

W. N. Brandt, S. Mathur, M. Elvis

The soft (\approx 0.1--2.0 keV) X-ray spectra of narrow-line Seyfert 1 galaxies are known to be generally steeper than those of Seyfert 1 galaxies with broader optical permitted lines. This has been attributed to the presence of strong soft X-ray excesses, over the hard X-ray power law, in many narrow-line Seyfert 1s. Here we use the currently available ASCA

John P. Blakeslee

A study of the globular cluster systems of 23 brightest, or central, galaxies in 19 Abell clusters has recently been completed. This Letter presents some of the newly discovered correlations of the globular cluster specific frequency $S_N$ in these galaxies with other galaxy and cluster properties and puts forth an interpretation of these results. $S_N$ is f

V. Lakshmibai, Peter Magyar

We construct an explicit basis for the coordinate ring of the Bott-Samelson variety Z_i associated to G = GL(n) and an arbitrary sequence of simple reflections i. Our basis is parametrized by certain standard tableaux and generalizes the Standard Monomial basis for Schubert varieties. Our standard tableaux have a natural crystal graph structure.

Jose A. Zapata

The canonical quantization of diffeomorphism invariant theories of connections in terms of loop variables is revisited. Such theories include general relativity described in terms of Ashtekar-Barbero variables and extension to Yang-Mills fields (with or without fermions) coupled to gravity. It is argued that the operators induced by classical diffeomorphism

Jochen Rau

The effective dynamics of a slow classical system coupled to a fast chaotic environment is described by means of a Master equation. We show how this approach permits a very simple derivation of geometric magnetism.

HongSheng Zhao

Increasing evidences suggest that the Galactic halo is lumpy on kpc scales due to the accretion of at least a dozen small galaxies (LMC/SMC, Sgr, Fornax etc.). Faint stars in such lumpy structures can significant microlense a background star with an optical depth $10^{-7}-10^{-6}$, which is comparable to the observed value to the LMC (Alcock et al. 1996c). T

Satoshi Iso, Andrew Kavalov

We calculate smoothed correlators for a large random matrix model with a potential containing products of two traces $\tr W_1(M) \cdot \tr W_2(M)$ in addition to a single trace $\tr V(M)$. Connected correlation function of density eigenvalues receives corrections besides the universal part derived by Brezin and Zee and it is no longer universal in a strong s

W. Tittel, J. Brendel, T. Herzog, H. Zbinden

An experimental demonstration of quantum correlations is presented. Energy and time entangled photons at wavelengths of 704 and 1310 nm are produced by parametric downconversion in KNbO3 and are sent through optical fibers into a bulk-optical (704 nm) and an all-fiber Michelson-interferometer (1310 nm), respectively. The two interferometers are located 35 me

Tatsuya Akasaka, Masaki Kashiwara

We present a conjecture on the irreducibility of the tensor products of fundamental representations of quantized affine algebras. This conjecture implies in particular that the irreducibility of the tensor products of fundamental representations is completely described by the poles of the R-matrices. The conjecture is proved in certain cases.

Masako Bando, Joe Sato, Koichi Yoshioka

We investigate the infrared fixed point structure in asymptotically free and asymptotically non-free theory. We find that the ratios of couplings converge strongly to their infrared fixed points in the asymptotically non-free theory.

J. F. Gunion, L. Poggioli, R. Van Kooten

We outline issues examined and progress made by the Light Higgs Snowmass 1996 working group regarding discovering Higgs bosons and measuring their detailed properties. We focused primarily on what could be learned at LEP2, the Tevatron (after upgrade), the LHC, a next linear $\epem$ collider and a $\mupmum$ collider.

M. L. Walker, C. J. Burden

Supersymmetry is studied in 2+1 dimensions. In addition to the multiplets corresponding to those in 3+1 dimensions the Clifford algebra allows an extra set. When the extra chiral multiplet is included, formulating supersymmetric QED3 in the manner of Wess and Zumino yields a lagrangian with a richer 'chiral' symmetry than that derived from supersymme

George Kastrinakis

Based on an unconventional Fermi liquid model, we present several results on the optimally doped and overdoped cuprate superconductors. For the normal state, we provide an analytic demonstration, backed by self-consistent Baym-Kadanoff (BK) numerical calculations, of the linear in $T$ resistivity and linear in 1/$ε$ optical conductivity, provided the interac

Jan de Boer, Kentaro Hori, Yaron Oz

We study the structure of the moduli spaces of vacua and superpotentials of N=2 supersymmetric gauge theories in three dimensions. By analyzing the instanton corrections, we compute the exact superpotentials and determine the quantum Coulomb and Higgs branches of the theories in the weak coupling regions. We find candidates for non-trivial N=2 superconformal

H. Zbinden, J. D. Gautier, N. Gisin, B. Huttner

Quantum Cryptography over 23km of installed Telecom fiber using a novel interferometer with Faraday mirrors is presented. The interferometer needs no alignment nor polarization control and features 99.8% fringe visibility. A secret key of 20kbit length with a error rate of 1.35% for 0.1 photon per pulse was produced.

K. Morawetz

An analytical solution of the selfconsistent Vlasov equation is presented. The time evolution is entirely determined by the initial distribution function. The largest Lyapunov exponent is calculated analytically. For special parameters of the model potential positive Lyapunov exponent is possible. This model may serve as a check for numerical codes solving s

J. Brachmann, A. Dumitru, J. A. Maruhn, H. Stöcker

To describe ultrarelativistic heavy-ion collisions we construct a three-fluid hydrodynamical model. In contrast to one-fluid hydrodynamics, it accounts for the finite stopping power of nuclear matter, i.e. for nonequilibrium effects in the early stage of the reaction. Within this model, we study baryon dynamics in the BNL-AGS energy range. For the system Au+

M. Sander, H. V. von Geramb

Low energy scattering and bound state properties of the πN, ππand Kπsystems are studied as coupled channel problems using inversion potentials of phase shift data. In a first step we apply the potential model to explain recent measurements of pionic hydrogen shift and width. Secondly, predictions of the model for pionium lifetime and shift confirm a well kno

H. Heiselberg, A. P. Vischer

Bose-Einstein correlations in relativistic heavy ion collisions are examined in a general model containing the essential features of hydrodynamical, cascade as well as other models commonly employed for describing the particle freeze-out. In particular the effects of longitudinal and transverse expansion, emission from surfaces moving in time, the thickness

Steven A. Bleiler, Amelia C. Jones

Techniques are introduced which determine the geometric structure of non-simple two-generator $3$-manifolds from purely algebraic data. As an application, the satellite knots in the $3$-sphere with a two-generator presentation in which at least one generator is represented by a meridian for the knot are classified.

S. Pinsky

We consider a dimensional reduction of 3+1 dimensional SU(N) Yang-Mills theory coupled to adjoint fermions to obtain a class of 1+1 dimensional gauge theories. We derive the quantized light-cone Hamiltonian in the light-cone gauge A^+ = 0$ and large-N limit, then solve for the masses, wavefunctions and of the color singlet boson and fermion boundstates. We f

K. Itakura, S. Maedan

Spontaneous symmetry breaking of the light-front Gross-Neveu model is studied in the framework of the discretized light-cone quantization. Introducing a scalar auxiliary field and adding its kinetic term, we obtain a constraint on the longitudinal zero mode of the scalar field. This zero-mode constraint is solved by using the $1/N$ expansion. In the leading

Billy D. Jones

We study the QED bound-state problem in a light-front hamiltonian approach. It is important to establish the equivalence (or not) of equal-time and light-front approaches in the well-understood arena of Quantum Electrodynamics. Along these lines, the singlet-triplet ground state spin splitting in positronium is calculated. The well-known result, $(7/6) α^2 R

Herbert Nachbagauer

We reformulate time evolution of systems in mixed states in terms of the classical observables of correlators using the Weyl correspondence rule. The resulting equation of motion for the Wigner functional of the density matrix is found to be of the Liouville type. To illustrate the methods developed, we explicitly consider a scalar theory with quartic self-i

A. A. Deriglazov, A. V. Galajinsky

The new extensions of the Poincaré superalgebra recently found in ten and eleven dimensions are shown to admit a linear realization. The generators of the nonlinear and linear group transformations are shown to fall into equivalent representations of the superalgebra. The parametrization of the coset space $G/H$, with $G$ a given extended supergroup and $H$

M. J. Duncan, M. H. Reno

We examine a method of studying the Z polarization in $H\to ZZ \to \ell^+ \ell^- ν\barν$ in proton-proton collisions at the Large Hadron Collider (LHC). Included are the dominant contributions: gluon fusion production of the Higgs boson, continuum production of Z pairs, and the Z+missing jet QCD background. The polarization signal is distinguishable from the

D. Boyanovsky, D. Cormier, H. J. de Vega, R. Holman

We study the non-linear dynamics of quantum fields in matter and radiation dominated universes, using the non-equilibrium field theory approach combined with the non-perturbative Hartree and the large N approximations. We examine the phenomenon of explosive particle production due to spinodal instabilities and parametric amplification in expanding universes

Mariano Quiros

We have analyzed baryogenesis in the MSSM for the light stop scenario, where the phase transition is strong enough first order. We have found that enough baryon asymmetry can be generated provided that the phase of $μ$ be $\simgt$ 0.01. Constraints from the electric dipole moment of the neutron enforce the first and second generation squarks to have masses O

A. A. Natale

It is known that the short distance QCD contribution to the mass difference of pions is quadratic on the quark masses, and irrelevant with respect to the long distance part. It is also considered in the literature that its calculation contain infinities, which should be absorbed by the quark mass renormalization. Following a prescription by Craigie, Narison

Y. Kanazawa, Yuji Koike

We study the Q^2 evolution of the nucleon's chiral-odd twist-3 distribution h_L(x,Q^2) starting from the MIT bag model calculation. A simple GLAP equation for h_L(x,Q^2) obtained at large N_c is used for the Q^2 evolution. The correction due to the finite value of N_c is O(1/N_c^2)\sim 10% level. It turns out that the twist-3 contribution to h_L(x,Q^2) i

B. L. Ioffe

It is proved, that suggested by Jin modified formalism in the external-field method in QCD sum rules exactly coincides with the formalism used before. Therefore, unlike the claims of ref.1, this formalism cannot improve the predictability and reliability of external-field sum rule calculations in comparison with those, done by the standard approach. PACS num

Yoshiharu Kawamura, Tatsuo Kobayashi, Jisuke Kubo

It is shown that a certain sum rule for soft supersymmetry-breaking scalar masses, which has been recently found in a certain class of superstring models, is universal for gauge-Yukawa unified models. To explain this coincidence, we argue that the low-energy remnant of the target-space duality invariance in the effective supergravity of compactified superstr

O. V. Tarasov

An algorithm for calculating two-loop propagator type Feynman diagrams with arbitrary masses and external momentum is proposed. Recurrence relations allowing to express any scalar integral in terms of basic integrals are given. A minimal set consisting of 15 essentially two-loop and 15 products of one-loop basic integrals is found. Tensor integrals and integ

L. Clavelli, I. Terekhov

In the light gluino scenario, squarks in the 100 GeV mass region can be copiously produced at the Tevatron without a second heavy particle. Their subsequent dijet decay into quark plus gluino leads to non-scaling structure in the inclusive jet X_T distribution. The expected behavior is similar to recent observations.

Giuliano Preparata, She-Sheng Xue

The ``no-go'' theorem of Nielsen and Ninomiya has been the most tenacious obstacle against the construction of a chiral gauge theory with reasonable low energy spectrum, couplings and anomaly. In this paper we construct a model which supplements the usual (bilinear in the Fermi fields) lagrangian with quadrilinear fermionic terms. We show that in a c

Jose A. Zapata

Quantum gauge theory in the connection representation uses functions of holonomies as configuration observables. Physical observables (gauge and diffeomorphism invariant) are represented in the Hilbert space of physical states; physical states are gauge and diffeomorphism invariant distributions on the space of functions of the holonomies of the edges of a c

Alan D. Rendall

The asymptotic behaviour of vacuum Bianchi models of class A near the initial singularity is studied, in an effort to confirm the standard picture arising from heuristic and numerical approaches by mathematical proofs. It is shown that for solutions of types other than VIII and IX the singularity is velocity dominated and that the Kretschmann scalar is unbou

A. Mikovic, V. Radovanovic

We determine the one-loop and the two-loop back-reaction corrections in the spectrum of the Hawking radiation for the CGHS model of 2d dilaton gravity by evaluating the Bogoliubov coefficients for a massless scalar field propagating on the corresponding backgrounds. Since the back-reaction can induce a small shift in the position of the classical horizon, we

Z. Ya Turakulov

An example of mechanical system whose configuration space is direct product of a curved space and the local group of rotations, is presented. The system is considered as a model of spinning particle moving in the space. The Hamiltonian formalism for this system and possible method for its quantization are discussed. It is shown that the Hamilton equations co

C. D. Batista, L. O. Manuel, H. A. Ceccatto, A. A. Aligia

We consider the slave-fermion Schwinger-boson decomposition of an effective model obtained through a systematic low-energy reduction of the three-band Hubbard Hamiltonian. The model includes a three-site term t'' similar to that obtained in the large-U limit of the Hubbard model but of opposite sign for realistic or large O-O hopping. For parameters

Laurent J. Lewis, Pablo Jensen, Jean-Louis Barrat

We present a detailed molecular-dynamics study of the melting, freezing, and coalescence of gold nanoclusters within the framework of the embedded-atom method. Concerning melting, we find the process to first affect the surface (``premelting''), then to proceed inwards. The curve for the melting temperature vs cluster size is found to agree reasonabl

Yan V. Fyodorov, Boris A. Khoruzhenko, H. -J. Sommers

By using the method of orthogonal polynomials we analyze the statistical properties of complex eigenvalues of random matrices describing a crossover from Hermitian matrices characterized by the Wigner- Dyson statistics of real eigenvalues to strongly non-Hermitian ones whose complex eigenvalues were studied by Ginibre. Two-point statistical measures (as e.g.

A. R. Denton, P. A. Egelstaff

The influence of periodic boundary conditions (implicit finite-size effects) on the anisotropy of pair correlations in computer simulations is studied for a dense classical fluid of pair-wise interacting krypton atoms near the triple point. Molecular dynamics simulation data for the pair distribution function of N-particle systems, as a function of radial di

J. Kisker, H. Rieger

We investigate the Bose glass phase and the insulator-to-superfluid transition in the two-dimensional disordered boson Hubbard model in the Villain representation via Monte Carlo simulations. In the Bose glass phase the probability distribution of the local susceptibility is found to have a $1/ χ^2$ tail and the imaginary time Green's function decays alg

Alan R. Bishop, Heinrich Röder

The history and recent developments in studying (colossal) magnetoresistance in perovskite manganese oxides is reviewed. We emphasize the growing evidence for strongly coupled spin, charge and lattice degrees of freedom. Together with disorder, these provide the microscopic driving forces for local and inhomogeneous textures. The modeling and experimental pr

V. I. Valtchinov, G. Kalman, K. Blagoev

The strongly correlated liquid state of a bilayer of charged particles has been studied via the HNC calculation of the two-body functions. We report the first time emergence of a series of structural phases, identified through the behavior of the two-body functions.

H. Roder, R. R. P. Singh, J. Zang

We present a high temperature series expansion for the ferromagnetic Kondo lattice model in the large coupling limit, which is used to model CMR perovskites. Our results show the expected cross-over to Curie-Weiß behavior at a temperature related to the bandwidth. Estimates for the magnetic transition temperatures are in the experimentally observed range. Th

Shun-Qing Shen

In this paper, we prove that the ground state of the Kondo model with large spin is nondegenerate, apart from a SU(2) spin degeneracy in the case of half filling. The ground state spin is found for the system, and the energy level orderings are discussed. Finally, the existence of ferrimagnetism in some cases is proved.

K. Morawetz

The quantum kinetic equation for charged particles in strong electric fields is derived and analyzed with respect to the particle flux. It is found that the applied electric field is screened nonlinearly. The relaxation field is calculated completely quantum mechanically and up to any order in the applied field. The classical limit is given in analytical for

Marko Robnik, Junxian Liu

We apply the generalized formalism and the techniques of the supersymmetric (susy) quantum mechanics to the cases where the superpotential is generated/defined by higher excited eigenstates (Robnik 1997, paper I). The generalization is technically almost straightforward but physically quite nontrivial since it yields an infinity of new classes of susy-partne

Aneta Siemiginowska, Martin Elvis

We have derived the quasar luminosity function assuming that the quasar activity is driven by a thermal-viscous unstable accretion disk around a supermassive black hole. The instabilities produce large amplitude, long-term variability of a single source. We take a light curve of a single source and calculate the luminosity function, from the function of time

J. -M. Hameury, J. -P. Lasota, J. E. McClintock, R. Narayan

We show that the time delay between the optical and X-ray outbursts of the black-hole soft X-ray transient source GRO J1655-40, observed in April 1996, requires that the accretion flow in this object must consist of two components: a cold outer accretion disk and an extremely hot inner advection-dominated accretion flow (ADAF). In quiescence, the model predi

F. P. Pijpers

The residence time of dust grains inside turbulent molecular clouds is calculated. Earlier estimates of this time by Boland & de Jong (1982) have been criticized by Prasad et al. (1987) for not taking into account properly the turbulent character of the velocity field in molecular clouds which implies that the trajectory of a dust grain should be treated as

R. Guzman, A. C. Phillips, J. Gallego, D. C. Koo

We study the global scaling-laws of 51 compact field galaxies with redshifts z = 0.2-1.3 and apparent magnitudes I<23.74 in the flanking fields of the Hubble Deep Field. Roughly 60% of the 45 compact emission-line galaxies have sizes, surface brightnesses, luminosities, velocity widths, excitations, star formation rates (SFR), and mass-to-light ratios charac

Steven Bradlow, James Glazebrook, Franz Kamber

In order to use the technique of dimensional reduction, it is usually necessary for there to be a symmetry coming from a group action. In this paper we consider a situation in which there is no such symmetry, but in which a type of dimensional reduction is nevertheless possible. We obtain a relation between the Coupled Vortex equations on a closed Kahler man

Randall D. Kamien

We present an alternative local definition of the writhe of a self-avoiding closed loop which differs from the traditional non-local definition by an integer. When studying dynamics this difference is immaterial. We employ a formula due to Aldinger, Klapper and Tabor for the change in writhe and propose a set of local, link preserving dynamics in an attempt

M. Cvetic, D. A. Demir, J. R. Espinosa, L. Everett

We consider electroweak symmetry breaking in supersymmetric models with an extra non-anomalous U(1)&#39; gauge symmetry and an extra standard-model singlet scalar S. For appropriate charges the U(1)&#39; forbids an elementary mu term, but an effective mu is generated by the VEV of S, leading to a natural solution to the mu problem. There are a variety of sce

W. A. Sabra

We find general static BPS black hole solutions for general N=2, d=4 supergravity theories with an arbitrary number of vector multiplets. These solutions are completely specified by the Kähler potential of the underlying special Kähler geometry and a set of constrained harmonic functions.

Mark Friesen, Paul Muzikar

The intermediate 3D XY scaling theory of superconductivity at zero and nonzero magnetic fields is developed, based only upon the dimensional hypothesis $B\sim (Length)^{-2}$. Universal as well as nonuniversal aspects of the theory are identified, including background terms and demagnetization effects. Two scaling regions are predicted: an &#34;inner&#34; reg

Igor Bandos, Wolfgang Kummer

A generalization of the embedding approach for d-dimensional gravity based upon p-brane theories is considered. We show that the D-dimensional p-brane coupled to an antisymmetric tensor field of rank (p+1) provides the dynamical basis for the description of d=(p+1) dimensional gravity in the isometric embedding formalism. &#39;&#39;Physical&#39;&#39; matter

Dror Bar-Natan, Stavros Garoufalidis, Lev Rozansky, Dylan P. Thurston

We conjecture an exact formula for the Kontsevich integral of the unknot, and also conjecture a formula (also conjectured independently by Deligne) for the relation between the two natural products on the space of Chinese characters. The two formulas use the related notions of &#34;Wheels&#34; and &#34;Wheeling&#34;. We prove these formulas &#34;on the level

James G. Bartlett

In gaussian theories of structure formation, the galaxy cluster abundance is an extremely sensitive probe of the density fluctuation power spectrum and of the density parameter, $Ω$. We develop this theme by deriving and studying in detail the mass function of collapsed objects and its relation to these quantities. Application to current data yields constrai

Ulf H. Danielsson, Gabriele Ferretti, Jussi Kalkkinen, Pär Stjernberg

We investigate consistency conditions for supersymmetric gauge theories in higher dimensions. First, we give a survey of Seiberg&#39;s necessary conditions for the existence of such theories with simple groups in five and six dimensions. We then make some comments on how theories in different dimensions are related. In particular, we discuss how the Landau p

V. V. Nesterenko, I. G. Pirozhenko

A consistent procedure for regularization of divergences and for the subsequent renormalization of the string tension is proposed in the framework of the one-loop calculation of the interquark potential generated by the Polyakov-Kleinert string. In this way, a justification of the formal treatment of divergences by analytic continuation of the Riemann and Ep

S. Marini, D. Khomskii

The quasi 2-d spin 1/2 materials CaV_nO_2n+1 (n=2,3,4) are often treated as systems in which quantum effects play a dominant role: CaV_2O_5 has a spin gap and is thought to be a spin ladder; CaV_3O_7 has unusual long-range magnetic order which is explained by quantum fluctuations; the spin gap in CaV_4O_9 is usually attributed to the formation of plaquette R

W. Buchmueller, A. Hebecker, M. F. McDermott

The diffractive production of open charm in deep-inelastic scattering is studied in the semiclassical approach which has been proposed recently. In this approach, the leading order process contains a charm quark pair and an additional gluon in the diffractive final state. The $p_{\perp}$-spectrum and the diffractive mass distribution are evaluated and compar

Nivedita Deo

Exact eigenvalue correlation functions are computed for large $N$ hermitian one-matrix models with eigenvalues distributed in two symmetric cuts. An asymptotic form for orthogonal polynomials for arbitrary polynomial potentials that support a $Z_2$ symmetric distribution is obtained. This results in an exact explicit expression for the kernel at large $N$ wh

Masahiro Anazawa

We investigate the multi-loop correlators and the multi-point functions for all of the scaling operators in unitary minimal conformal models coupled to two-dimensional gravity from the two-matrix model. We show that simple fusion rules for these scaling operators exist, and these are summarized in a compact form as fusion rules for loops. We clarify the role

B. Mobasher, R. Guzman, A. Aragon-Salamanca, S. Zepf

Near-infrared (2.2 $μm$) observations of a sample of 48 elliptical galaxies in the Coma cluster have been carried out and used to study the near-ir fundamental plane (FP) of ellipticals in this cluster. An rms scatter of 0.072 dex was found for this relation, similar to that of its optical counterpart, using the same sample of galaxies. This corresponds to a

S. Stintzing, W. Zwerger

We consider Fermions in two dimensions with an attractive interaction in the singlet d-wave channel of arbitrary strength. By means of a Hubbard-Stratonovich transformation a statistical Ginzburg-Landau theory is derived, which describes the smooth crossover from a weak-coupling BCS superconductor to a condensate of composite Bosons. Adjusting the interactio

Carlos Castro

Since the lightcone self dual spherical membrane, moving in flat target backgrounds, has a direct correspondence with the $SU(\infty)$ Nahm equations and the continuous Toda theory, we construct the Moyal deformations of the self dual membrane in terms of the Moyal deformations of the continuous Toda theory. This is performed by using the Weyl-Wigner-Moyal q

Y. Shadmi

The messenger sector of existing models of gauge-mediated supersymmetry breaking may be simplified by using a non-renormalizable superpotential term to couple the vector-like quark and lepton messenger fields to a chiral gauge-invariant of the supersymmetry-breaking sector. This eliminates the need for a fundamental singlet and for an additional gauge sector

V. Barger, Kingman Cheung, K. Hagiwara, D. Zeppenfeld

We consider $e e q q$ contact interactions as a possible origin of an excess of events above Standard Model predictions in $e^+ p \to e^+ jet$ at high $Q^2$ observed by the H1 and ZEUS collaborations at HERA. The HERA data prefer chirality RL or LR contact terms and atomic physics parity violation measurements severely limit parity-odd contact terms. With eq

Ming Li, Paul Vitanyi

Future miniaturization and mobilization of computing devices requires energy parsimonious `adiabatic' computation. This is contingent on logical reversibility of computation. An example is the idea of quantum computations which are reversible except for the irreversible observation steps. We propose to study quantitatively the exchange of computational resou

Gyula Bene

A new interpretation of nonrelativistic quantum mechanics is presented. It explains the violation of Bell&#39;s inequality by maintaining realism and the principle of locality. Schrodinger&#39;s cat paradox and the Einstein-Podolsky-Rosen paradox are solved, too. The new approach assumes the universal validity of the Schrodinger equation, while von Neumann&#

Mircea Micu

We found hermitian realizations of the position vector $\vec{r}$, angular momentum $\vecΛ$ and linear momentum $\vec{p}$ behaving like vectors with respect to the $SU_q(2)$ algebra, generated by $L_0$ and $L_\pm$. They are used to write the $q$ deformed Schrödinger equation, whose solution for Coulomb and oscillator potential are briefly discussed.

K. Hagino, N. Takigawa, S. Kuyucak

We discuss the effects of double octupole and quadrupole phonon excitations in $^{144}$Sm on fusion reactions between $^{16}$O and $^{144}$Sm at subbarrier energies. The effects of anharmonicities of the vibrational states are taken into account by using the $sdf$-interacting boson model. We compare the results with those in the harmonic limit to show that a

Joel David Hamkins, Simon Thomas

If $G$ is a centreless group, then $τ(G)$ denotes the height of the automorphism tower of $G$. We prove that it is consistent that for every cardinal $λ$ and every ordinal $α< λ$, there exists a centreless group $G$ such that (a) $τ(G) = α$; and (b) if $β$ is any ordinal such that $1 \leq β< λ$, then there exists a notion of forcing $P$, which preserves cofi

W. Fischler, E. Halyo, A. Rajaraman, L. Susskind

Using M(atrix) Theory, the dualities of toroidally compactified M-theory can be formulated as properties of super Yang Mills theories in various dimensions. We consider the cases of compactification on one, two, three, four and five dimensional tori. The dualities required by string theory lead to conjectures of remarkable symmetries and relations between fi

Q-Han Park, H. J. Shin

We show the quantum equivalence between certain symmetric space sine-Gordon models and the massive free fermions. In the massless limit, these fermions reduce to the free fermions introduced by Goddard, Nahm and Olive (GNO) in association with symmetric spaces $K/G$. A path integral formulation is given in terms of the Wess-Zumino-Witten action where the fie

M. Suzuki

We look for a mechanism that removes without numerical fine tuning the strong constraint imposed by the flavor changing neutral current interaction of leptoquark exchange. If n x n degenerate leptoquarks couple universally to n generations of quarks and leptons in the weak basis, not only can the neutral current interactions be flavor diagonal, but also the

A. D. Dolgov, S. H. Hansen, D. V. Semikoz

Distortion of the equilibrium spectra of cosmic neutrinos due to interaction with hotter electrons and positrons in the primeval cosmic plasma is considered. The set of integro-differential kinetic equations for neutrinos is accurately numerically solved. The relative corrections to neutrino energy densities are approximately 0.9% for $ν_e$ and 0.4% for $ν_μ

A. Bramon, R. Escribano, M. D. Scadron

The octet-singlet mixing angle $θ_P$ in the pseudoscalar meson nonet is deduced from the rich set of accurate data on $J/ψ$ decays into a vector and a pseudoscalar meson. Corrections due to non-ideal $ω$-$ϕ$ mixing have been included for the first time and turn out to be crucial to find $θ_P = -16.9 \pm 1.7$ degrees, which is appreciably less negative than p

C. T. H. Davies, K. Hornbostel, G. P. Lepage, P. McCallum

We present a new determination of the strong coupling constant from lattice QCD simulations. We use four different short-distance quantities to obtain the coupling, three different (infrared) meson splittings to tune the simulation parameters, and a wide range of lattice spacings, quark masses, and lattice volumes to test for systematic errors. Our final res

D0 Collaboration, S. Abachi

We measure the top quark mass m_t using t tbar pairs produced in the D0 detector by root(s) = 1.8 TeV p pbar collisions in a 125 pb^-1 exposure at the Fermilab Tevatron. We make a two constraint fit to m_t in t tbar --> b W^+ bbar W^- final states with one W decaying to q qbar and the other to e nu or mu nu. Events are binned in fit mass versus a measure of

Naresh Dadhich, K. Narayan, U. A. Yajnik

We derive the metric for a Schwarzschild black hole with global monopole charge by relaxing asymptotic flatness of the Schwarzschild field. We then study the effect of global monopole charge on particle orbits and the Hawking radiation. It turns out that existence, boundedness and stability of circular orbits scale up by $(1-8 πη^2)^{-1}$, and the perihelion

R. Loll

We point out that the inequality det E > 0 distinguishes the kinematical phase space of canonical connection gravity from that of a gauge field theory, and characterize the eigenvectors with positive, negative and zero-eigenvalue of the corresponding quantum operator in a lattice-discretized version of the theory. The diagonalization of the operator det E is

Johan Kustermans

We introduce the notion of a C*-valued weight between two C*-algebras as a generalization of an ordinary weight on a C*-algebra and as a C*-version of operator valued weights on von Neumann algebras. Also, some form of lower semi-continuity will be discussed together with an extension to the multiplier algebra. A strong but useful condition for C*-valued wei

Z. Shuai, J. L. Bredas, S. K. Pati, S. Ramasesha

The symmetrized density matrix renormalization group approach is applied within the extended Hubbard-Peierls model (with parameters U/t, V/t, and bond alternation δ) to study the ordering of the lowest one-photon (1^{1}B^{-}_u) and two-photon (2^{1}A^{+}_g) states in one- dimensional conjugated systems with chain lengths, N, up to N=80 sites. Three different

Sudip Chakravarty

Josephson plasma frequency is computed within the interlayer tunneling theory and compared against the experimental results in Tl_2Ba_2CuO_y and La_{2-x}Sr_xCuO_4. It is shown that the theoretical estimates are fully consistent with the recent experiments.

Andrei D. Zaikin, Dmitrii S. Golubev, Anne van Otterlo, Gergely T. Zimányi

We reply to the recent Comment [cond-mat/9702231] by J.-M. Duan. Our point of view is markedly different on every issue raised. Much of the disagreement can be traced to a different preception of experimentally relevant length scales. i) We explain the difference between our formulation, which rests on a microscopic basis, and the phenomenological one of the

Lan Yin, Sudip Chakravarty

The low temperature correlation length and the static structure factor are computed for bilayer antiferromagnets such as YBa_2Cu_3O_6. It is shown that energy integrated two-axis scan in neutron scattering experiments can be meaningfully interpreted to extract correlation length in such bilayer antiferromagnets despite intensity modulation in the momentum pe

S. Flesia

Recent work on the complete wetting transition for three dimensional systems with short-ranged forces has emphasized the role played by the coupling of order-parameter fluctuations near the wall and depinning interface. It has been proposed that an effective two-field Hamiltonian, which predicts a renormalisation of the wetting parameter, could explain the c

Daniel A. Lidar, Ofer Biham, David Avnir

Multiple resolution analysis of two dimensional structures composed of randomly adsorbed penetrable rods, for densities below the percolation threshold, has been carried out using box-counting functions. It is found that at relevant resolutions, for box-sizes, $r$, between cutoffs given by the average rod length $<\ell>$ and the average inter-rod distance $r

C. De Dominicis, D. M. Carlucci, T. Temesvari

The analysis of objects living on ultrametric trees, in particular the block-diagonalization of 4-replica matrices $M^{αβ; γδ}$, is shown to be dramatically simplified through the introduction of properly chosen operations on those objects. These are the Replica Fourier Transforms on ultrametric trees. Those transformations are defined and used in the presen

Ramon Aguado, Gloria Platero, Miguel Moscoso, Luis L. Bonilla

We propose a selfconsistent microscopic model of vertical sequential tunneling through a multi-quantum well.The model includes a detailed description of the contacts,uses the Transfer Hamiltonian for expressions of the current and it treats the Coulomb interaction within a mean field approximation. We analyze the current density through a double well and a s

Kicheon Kang, B. I. Min

Employing the Anderson impurity model, we study tunneling properties through an ideal quantum dot near the conductance minima. Considering the Coulomb blockade and the quantum confinement on an equal footing, we have obtained current contributions from various types of tunneling processes; inelastic cotunneling, elastic cotunneling, and resonant tunneling of

N. A. Levenson, J. R. Graham, B. Aschenbach, W. P. Blair

We describe and report progress on the joint U.S. and German campaign to map the X-ray emission from the entire Cygnus Loop supernova remnant with the ROSAT High Resolution Imager. The Cygnus Loop is the prototype for a supernova remnant that is dominated by interactions with the interstellar medium and supplies fundamental physical information on this basic

Willem Wamsteker, Wang Ting-gui, Norbert Schartel, Roberto Vio

We present an analysis of the ultraviolet and X-Ray variability of the Broad- Line-Radio Galaxy 3C390.3 over 15 years. The UV continuum showed large variations with amplitudes of up to a factor of 10. We find: (1) The variations of CIV and Ly_alpha are highly correlated with the UV continuum, and are delayed with respect to the continuum variations by 50-110