August 2000 arXiv papers — page 2

Lev Titarchuk, Vladimir Osherovich

We suggest that persistent low-frequency quasi-periodic oscillations (QPOs) detected in X-ray, ultraviolet, optical energy ranges the black hole (BH) sources XTE J1118+480, GRO J1655-40 LMC X-1 at ~ 0.1 Hz, and QPOs in HZ Her/Her X-1 at ~ 0.05 Hz and in Neutron Star (NS) binaries 4U 1323-62, 4U 1746-31 and EXO 0748-76 at ~ 1 Hz are caused by the global disk

Caroline E. J. M. L. J. Terquem

We discuss the transport of angular momentum induced by tidal effects in a disk surrounding a star in a pre-main sequence binary system. We consider the effect of both density and bending waves. Although tidal effects are important for truncating protostellar disks and for determining their size, it is unlikely that tidally-induced angular momentum transport

J. K. Kotilainen, R. Falomo

We present the results of near-infrared H-band (1.65 microns) imaging of 19 steep spectrum radio quasars (SSRQ) in the redshift range 0.5 < z < 1.0. This sample of SSRQs is matched with our previously studied complete sample of 20 flat spectrum radio quasars (FSRQ) with respect to redshift and optical and radio luminosity. We are able to clearly detect the h

Tomek Plewa

The advantages and disadvantages of two approaches to astrophysical hydrodynamics, Smoothed Particle Hydrodynamics and Adaptive Mesh Refinement, are briefly discussed together with some current problems of computational hydrodynamics.

S. Huettemeister, S. Aalto, M. Das, W. F. Wall

We present sensitive interferometric 12CO, 13CO and HCN observations of the barred spiral galaxy NGC7479, known to be one of the few barred galaxies with a continuous gas-filled bar. We focus on the investigation and interpretation of 12CO/13CO line intensity ratios, which is facilitated by having more than 90% of the flux in our interferometer maps. The glo

M. A. Garrett, A. G. de Bruyn, M. Giroletti, W. A. Baan

We present deep WSRT 1.4 GHz observations of the Hubble Deep Field region. At the 5 sigma level, the WSRT clearly detects 85 regions of radio emission in a 10&#39; x 10&#39; field centred on the HDF. Eight of these regions fall within the HDF itself, four of these are sources that have not previously been detected at 1.4 GHz, although two of these are VLA de

Z. Paragi, S. Frey, I. Fejes, T. Venturi

Space very long baseline interferometry (VLBI) observations of the quasar 3C216 with the VLBI Space Observatory Programme (VSOP) reveal that the parsec scale structure of the source can be well described by compact jet models developed for interpreting the core region of radio-loud active galactic nuclei (AGN). The measured brightness temperature of T_(b) =

Hiroko Koyama, Tetsuro Konishi

The process of formation of fractal structure in one-dimensional self-gravitating system is examined numerically. It is clarified that structures created in small spatial scale grow up to larger scale through clustering of clusters, and form power-law correlation.

Francesco R. Ferraro, Barbara Paltrinieri, Francesco Paresce, Guido De Marchi

We present results from multi-band observations in the central region of the cluster NGC6712 with the ESO-Very Large Telescope. Using high resolution images we have identified three UV-excess stars. In particular two of them are within the cluster core, a few arcsec apart: the first object is star &#34;S&#34; which previous studies identified as the best can

T. Takahashi, J. Kataoka, G. Madejski, J. Mattox

We conducted a multi-frequency campaign for the TeV blazar Mrk~421 in 1998 April. The campaign started from a pronounced high amplitude flare recorded by SAX and Whipple; ASCA observation started three days later. In the X-ray data, we detected multiple flares, occuring on time scales of about one day. ASCA data clearly reveal spectral variability. The compa

M. R. Schreiber, B. T. Gaensicke, J. K. Cannizzo

We show that irradiation of the accretion disc by the white dwarf limits the occurrence of dwarf nova outbursts in post nova accretion discs. After the nova explosion, the white dwarf has to cool for up to ~100 yr - depending on the orbital period (i.e., disc size) and the temperature of the white dwarf after the nova-eruption - before the disc can begin pro

Steen Hannestad

Many independent high resolution simulations have indicated that the standard collisionless cold dark matter model does not reproduce the structure of observed present day galaxies well. Several possible solutions in the form of modifications to the physics of the dark matter particles have been proposed. One of the most promising is warm dark matter (WDM),

M. A. Perez-Torres, J. M. Marcaide, J. C. Guirado, E. Ros

On 18 November 1993, we observed the QSO 1150+812 and the BL Lac object 1803+784, nearly 15°apart on the sky, with a VLBI array, simultaneously recording at 8.4 and 2.3 GHz. Using difference astrometry techniques, we determined the coordinates of 1803+784 relative to those of 1150+812 to be Δα= 6h 7m 33.18469 arcsec +- 0.00020 arcsec Δδ= -2deg 30&#39; 25&#39

N. F. Bell, R. F. Sawyer, R. R. Volkas

We consider the time development of the density matrix for a system coupled to a thermal bath, in models that go beyond the standard two-level systems through addition of an energy excitation degree of freedom and through the possibility of the replacement of the spin algebra by a more complex algebra. We find conditions under which increasing the coupling t

Joseph A. Minahan, Barton Zwiebach

In hep-th/0008227, the unstable lump solution of ϕ^3 theory was shown to have a spectrum governed by the solvable Schroedinger equation with the \ell=3 reflectionless potential and was used as a model for tachyon condensation in string theory. In this paper we study in detail an \ell\to \infty scalar field theory model whose lump solution mimics remarkably t

Iosif Bena, Horatiu Nastase, Diana Vaman

In AdS_{2p+1} we construct propagators for p-forms whose lagrangians contain terms of the form A / d A. In particular we explore the case of forms satisfying ``self duality in odd dimensions&#39;&#39;, and the case of forms with a topological mass term. We point out that the ``complete&#39;&#39; set of maximally symmetric bitensors previously used in all the

Scott Burles, Kenneth M. Nollett, Michael S. Turner

Together, the standard theory of big-bang nucleosynthesis (BBN) and the primeval deuterium abundance now very precisely peg the baryon density. Based upon our analysis of the deuterium data and the theoretical uncertainties associated with the BBN predictions, we determine Omega_B h^2 = 0.020\pm 0.002 (95% C.L.), with the uncertainty from the measured deuter

Hisa-aki Shinkai, Sean A. Hayward

We numerically implement a quasi-spherical approximation scheme for computing gravitational waveforms for coalescing black holes, testing it against angular momentum by applying it to Kerr black holes. As error measures, we take the conformal strain and specific energy due to spurious gravitational radiation. The strain is found to be monotonic rather than w

A. Vikhlinin, M. Markevitch, S. S. Murray

We present results from a Chandra observation of the central region of the galaxy cluster A3667, with emphasis on the prominent sharp X-ray brightness edge spanning 0.5 Mpc near the cluster core. Our temperature map shows large-scale nonuniformities characteristic of the ongoing merger, in agreement with earlier ASCA results. The brightness edge turns out to

Steven Gratton, Neil Turok

We discuss the O(4) invariant perturbation modes of cosmological instantons. These modes are spatially homogeneous in Lorentzian spacetime and thus not relevant to density perturbations. But their properties are important in establishing the meaning of the Euclidean path integral. If negative modes are present, the Euclidean path integral is not well defined

Benjamin D. G. Chandran

Scattering rates for a Goldreich-Sridhar (GS) spectrum of anisotropic, incompressible, magnetohydrodynamic turbulence are calculated in the quasilinear approximation. Because the small-scale fluctuations are constrained to have wave vectors nearly perpendicular to the background magnetic field, scattering is too weak to provide either the mean free paths com

F. A. Chishtie, V. Elias

The three-loop contribution to the MS bar single-Higgs-doublet standard-model cross-section $σ(W_L^+ W_L^- \to Z_L Z_L)$ at s = (5M_H)^2 is estimated via least-squares matching of the asymptotic Pade-approximant prediction of the next order term, a procedure that has been previously applied to QCD corrections to correlation functions and decay amplitudes. In

Gyula Bene, Szabolcs Borsanyi

An &#34;almost diagonal&#34; reduced density matrix (in coordinate representation) is usually a result of environment induced decoherence and is considered the sign of classical behavior. We point out that the proton of a ground state hydrogen atom can possess such a density matrix. We demonstrate on this example that an &#34;almost diagonal&#34; reduced den

A. A. Belyanin, F. Capasso, V. V. Kocharovsky, Vl. V. Kocharovsky

A new scheme for infrared generation without population inversion between subbands in quantum-well and quantum-dot lasers is presented and documented by detailed calculations. The scheme is based on the simultaneous generation at three frequencies: optical lasing at the two interband transitions which take place simultaneously, in the same active region, and

S. Ivanov, G. Papadopoulos

We give necessary conditions for the existence of perturbative heterotic and common sector type II string warped compactifications preserving four and eight supersymmetries to four spacetime dimensions, respectively. In particular, we find that the only compactifications of heterotic string with the spin connection embedded in the gauge connection and type I

Michael McNeil Forbes, Ariel R. Zhitnitsky

QCD was shown to have a nontrivial vacuum structure due to the topology of the theta = theta+2*pi*n parameter. As a result of this nontrivial topology, in the large N_c limit, quasi-stable QCD domain walls appear, characterized by a transition in the singlet eta' field. We discuss the physics of these QCD domain walls as well as related axion domain walls an

Minu Joy, V. C. Kuriakose

Considering the theory of induced gravity coupled to matter fields, taking the $ϕ^6$ interaction potential model we evaluate the one-loop effective potential in a (3+1)dimensional Bianchi type-I spacetime. It is proved that the $ϕ^6$ theory can be regularised in (3+1)dimensional curved spacetime. We evaluate the finite temperature effective potential and stu

Ph. Hagler, R. Kirschner, A. Schafer, L. Szymanowski

The hadroproduction of direct J/Psi in the framework of the k_\perp-factorization approach is studied. The color-singlet contribution is essentially larger than in the collinear approach but is still an order of magnitude below the data. The deficit may be well described by the color octet contribution with the value of the matrix element <0|O^{J/Ψ}_8(^3S_1)

Joachim Krug

A Comment on PRL 85, 1480 (2000) by K.R. Roos and M.C. Tringides.

Matthias R. Gaberdiel

D-branes on orbifolds with and without discrete torsion are analysed in a unified way using the boundary state formalism. For the example of the Z2 x Z2 orbifold it is found that both the theory with and without discrete torsion possess D-branes whose world-volume carries conventional and projective representations of the orbifold group. The resulting D-bran

Nir J. Shaviv

We present a model for steady state winds of systems with super-Eddington luminosities. These radiatively driven winds are expected to be optically thick and clumpy as they arise from an instability driven porous atmosphere. The model is then applied to derive the mass loss observed in bright classical novae. The main results are: 1) A general relation betwe

Arnon Dar, Alvaro De Rujula

Recent observations suggest that the long-duration gamma ray bursts (GRBs) and their afterglows are produced by highly relativistic jets emitted in supernova explosions. We propose that the result of the event is not just a compact object plus the ejecta: within a day, a fraction of the parent star falls back to produce a thick accretion disk. The subsequent

Simon Portegies Zwart, Junichiro Makino, Stephen McMillan, Piet Hut

We study the evolution and observability of young compact star clusters within about 200pc of the Galactic center. Calculations are performed using direct N-body integration on the GRAPE-4, including the effects of both stellar and binary evolution and the external influence of the Galaxy. The results of these detailed calculations are used to calibrate a si

A. Patrascioiu, E. Seiler

We study the universality between a discrete spin model with icosahedral symmetry and the O(3) model in two dimensions. For this purpose we study numerically the renormalized two-point functions of the spin field and the four point coupling constant. We find that those quantities seem to have the same continuum limits in the two models. This has far reaching

Doron Cohen, Alex Barnett, Eric J. Heller

We consider a classically chaotic system that is described by a Hamiltonian H(Q,P;x), where (Q,P) describes a particle moving inside a cavity, and x controls a deformation of the boundary. The quantum-eigenstates of the system are |n(x)>. We describe how the parametric kernel P(n|m) = <n(x)|m(x0)>, also known as the local density of states, evolves as a func

D. A. H. Buckley, M. J. Coe, J. B. Stephens, K. van der Heyden

We report on two optical candidates for the counterpart to an X-ray source in the SMC, 1WGA J0053.8-7226, identified as a serendipitous X-ray source from the ROSAT PSPC archive, and also observed by the Einstein IPC. Its X-ray properties, namely the hard X-ray spectrum, flux variability and column density indicate a hard, transient source, with a luminosity

L. P. Grishchuk, V. M. Lipunov, K. A. Postnov, M. E. Prokhorov

The first generation of long-baseline laser interferometric detectors of gravitational waves will start collecting data in 2001-2003. We carefully analyse their planned performance and compare it with the expected strengths of astrophysical sources. The scientific importance of the anticipated discovery of various gravitatinal wave signals and the reliabilit

Stephan Dürr

The Leutwyler-Smilga prediction regarding the (ir)relevance of the global topological charge for QCD in a finite box is subject to a test. To this end the lattice version of a suitably chosen analogue (massive 2-flavour Schwinger model) is analyzed in the small ($VΣm \ll 1$), intermediate ($VΣm \simeq 1$) and large ($VΣm \gg 1$) Leutwyler-Smilga regimes. The

G. Seibold, M. Grilli

We show that the spectral lineshape of superconducting La$_{2-x}$Sr$_x$CuO$_4$ (LSCO) and Bi$_2$Sr$_2$CaCu$_2$O$_{8+δ}$ (Bi2212) can be well described by the coupling of the charge carriers to collective incommensurate charge-density wave (CDW) excitations. Our results imply that besides antiferromagnetic (AF) fluctuations also low-energy CDW modes can contr

Robert A Smith, Beccy S Handy, Vinay Ambegaokar

We calculate the transition temperature in ultranarrow superconducting wires as a function of wire width, resistance and applied magnetic field. We compare the results of first-order perturbation theory and the non-perturbative resummation technique developed by Oreg and Finkel'stein. The latter technique is found to be superior as it is valid even in the st

Giampiero Esposito

This paper proves that it is possible to build a Lagrangian for quantum electrodynamics which makes it explicit that the photon mass is eventually set to zero in the physical part on observational ground. Gauge independence is achieved upon considering the joint effect of gauge-averaging term and ghost fields. It remains possible to obtain a counterterm Lagr

Stephen J. Hardy, Markus H. Thoma

We present a new method of calculating the rate of neutrino-electron interactions in a strong magnetic field based on finite temperature field theory. Using this method, in which the effect of the magnetic field on the electron states is taken into account exactly, we calculate the rates of all of the lowest order neutrino-electron interactions in a plasma.

Chris Pearson, H. Matsuhara, H. Watarai, T. Matsumoto

We present basic observational strategies for ASTRO-F (also known as the Imaging Infra Red Surveyor (IRIS)) to be launched in 2004 by the Japanese Institute of Space and Astronautical Science (ISAS). We examine 2 survey scenarios, a deep ~1sq.deg. survey reaching sensitivities an order of magnitude below than the deepest surveys performed by ISO in the mid-I

Hae-Young Kee

We study the effect of disorder induced by doping on the transition temperature in high $T_c$ cuprates. Since the impurity lies between the CuO$_2$ planes, the momentum transfer is restricted by small angle with a range of order of $1/(d k_F)$, where $k_F$ is the Fermi momentum and $d$ is the distance between the plane and the impurity. We find that the lead

Nickolay Y. Gnedin, Andrew H. Jaffe

We use numerical simulation of cosmological reionization to calculate the secondary CMB anisotropies in a representative flat low density cosmological model. We show that the kinetic Sunyaev-Zel&#39;dovich effect (scattering off of moving electrons in the ionized intergalactic medium) is dominated by the nonlinear hydrodynamic and gravitational evolution of

Henry Cohn, Richard Kenyon, James Propp

We formulate and prove a variational principle (in the sense of thermodynamics) for random domino tilings, or equivalently for the dimer model on a square grid. This principle states that a typical tiling of an arbitrary finite region can be described by a function that maximizes an entropy integral. We associate an entropy to every sort of local behavior do

John R. Klauder

From the very beginning, coherent state path integrals have always relied on a coherent state resolution of unity for their construction. By choosing an inadmissible fiducial vector, a set of ``coherent states&#39;&#39; spans the same space but loses its resolution of unity, and for that reason has been called a set of weak coherent states. Despite having no

Andrew Thangaraj, Steven McLaughlin

We provide a construction for quantum codes (hermitian-self-orthogonal codes over GF(4)) starting from cyclic codes over GF(4^m). We also provide examples of these codes some of which meet the known bounds for quantum codes.

Gyula Bene

The status of locality in quantum mechanics is analyzed from a nonstandard point of view. It is assumed that quantum states are relative, they depend on and are defined with respect to some bigger physical system which contains the former system as a subsystem. Hence, the bigger system acts as a reference system. It is shown that quantum mechanics can be ref

Yunhai Cai, Alex W. Chao, Stephan I. Tzenov, Toshi Tajima

A highly accurate self-consistent particle code to simulate the beam-beam collision in $e^+e^-$ storage rings has been developed. It adopts a method of solving the Poisson equation with an open boundary. The method consists of two steps: assigning the potential on a finite boundary using the Green&#39;s function, and then solving the potential inside the bou

Donald A. Swenson

The Proof-of-Principle (POP) prototype of the Rf-Focused Drift tube (RFD) linac structure is currently under test at Linac Systems, after years of delay due to a variety of technical problems. A discussion of these technical problems and their solutions will be presented. The status of these tests will be reported. Plans for future development of this linac

Kevin K. Lehmann

This paper presents an analysis of a model problem, consisting of two interacting rigid rings, for the rotation of molecules in liquid $^4$He. Due to Bose symmetry, the excitation of the rotor corresponding to a ring of N helium atoms is restricted to states with integer multiples of N quanta of angular momentum. This minimal model shares many of the same fe

C. Adolphsen, K. L. F. Bane, V. A. Dolgashev, K. Ko

We show that scattering matrix calculations for dipole modes between 23-43 GHz for the 206 cell detuned structure (DS) are consistent with finite element calculations and results of the uncoupled model. In particular, the rms sum wake for these bands is comparable to that of the first dipole band. We also show that for RDDS1 uncoupled wakefield calculations

G. A. Kotel&#39;nikov

The violation of the invariance of the speed of light in Special Relativity has been made. The version of the theory (LSR) has been constructed in which the possibility of the superluminal motions are permitted. Some predictions of this theory are available for experimental check, for example, the measurements of aberration angles, the observation of distinc

Silas R. Beane, Paulo F. Bedaque, Wick C. Haxton, Daniel R. Phillips

The study of nuclei predates by many years the theory of quantum chromodynamics. More recently, effective field theories have been used in nuclear physics to ``cross the border&#39;&#39; from QCD to a nuclear theory. We are now entering the second decade of efforts to develop a perturbative theory of nuclear interactions using effective field theory. This wo

P. J. Ellis

Third order chiral perturbation theory accounts for the $π-N$ scattering phase shift data out to energies slightly below the position of the $Δ$ resonance. The low energy constants are not accurately determined. Explicit inclusion of the $Δ$ field is favored.

V. A. Rodin, M. H. Urin

An extended continuum-RPA approach is applied to describe direct-decay properties of spin giant resonances in $^{208}$Bi and $^{90}$Nb. Partial branching ratios for direct proton decay from these resonances are evaluated. The branching ratio for $γ$-decay from the spin-dipole resonance to the Gamow-Teller resonance (main peak) is estimated. The saturation-li

V. A. Rodin, M. H. Urin

The branching ratios for E1 transitions between the spin-dipole (SD) and Gamow-Teller (GT) giant resonances in $^{90}$Nb and $^{208}$Pb are evaluated. Assuming the main GT-state has the wave function close to that for the &#34;ideal&#34; GT-state, we reduced the problem to calculate the SD and GT strength functions. These strength functions are evaluated wit

Y. R. Shimizu, M. Matsuo, K. Yoshida

Decay of the superdeformed bands have been studied mainly concentrating upon the decay-out spin, which is sensitive to the tunneling probability between the super- and normal-deformed wells. Although the basic features are well understood by the calculations, it is difficult to precisely reproduce the decay-out spins in some cases. Comparison of the systemat

Katsuaki Sakamoto, Hiroaki Kouno, Akira Hasegawa, Masahiro Nakano

We calculate the effective mass m_ω^* of the ω-meson in nuclear medium by the σ-ωmodel with a vector field self-interaction (VFSI). We found that the direct and the indirect effects of the VFSI almost cancel each other and the result is changed only slightly at the normal density. The VFSI makes m^*_ωsmaller at lower density and makes m_ω^* larger at higher

B. Kämpfer, A. Peshier, G. Soff

A quasi-particle model is presented which describes QCD lattice results for the 0, 2 and 4 quark-flavor equation of state. The results are mapped to finite baryo-chemical potentials. As an application of the model we make a prediction of deconfined matter with appropriate inclusion of strange quarks and consider pure quark stars.

W. L. Qian, Ru-Keng Su, Ping Wang

By using the Furnstahl, Serot and Tang&#39;s model, the effect of density dependence of the effective nucleon-nucleon-rho-meson (NN-rho) coupling on the liquid-gas phase transition in hot asymmetric nuclear matter is investigated. A limit pressure p_lim has been found. We found that the liquid-gas phase transition cannot take place if p>p_lim. The binodal su

Gottfried Mayer-Kress

Among the metaphors used in the target article are &#34;musical instruments&#34;, &#34;water waves&#34;, and other types of mechanical oscillators. The corresponding equations have inertial properties and lead to standing waves that depend on boundary conditions. Other, physiologically relevant quantities like refractory times are not contained in the mechan

D. V. Ramana Reddy, A. Sen, G. L. Johnston

Experimental observations of time delay induced amplitude death in a pair of coupled nonlinear electronic circuits that are individually capable of exhibiting limit cycle oscillations are described. In particular, the existence of multiply connected death islands in the parameter space of the coupling strength and the time delay parameter for coupled identic

Xianzhe Dai, Hao Fang

We prove a formula relating the analytic torsion and Reidemeister torsion on manifolds with boundary in the general case when the metric is not necessarily a product near the boundary. The product case has been established by W. Luck and S. M. Vishik. We find that the extra term that comes in here in the nonproduct case is the transgression of the Euler clas

Iain R. Aitchison, J. Hyam Rubinstein

A combinatorial condition is obtained for when immersed or embedded incompressible surfaces in compact 3-manifolds with tori boundary components remain incompressible after Dehn surgery. A combinatorial characterisation of hierarchies is described. A new proof is given of the topological rigidity theorem of Hass and Scott for 3-manifolds containing immersed

Alejandro Adem, Jon F. Carlson, Dikran Karagueuzian, R. James Milgram

In this paper we compute the mod 2 cohomology of the Sylow 2-subgroup of the Higman-Sims group HS, one of the 26 sporadic simple groups. We obtain its Poincare series as well as an explicit description of it as a ring with 17 generators and 79 relations

Alejandro Adem, Jonathan Pakianathan

We use topological methods to compute the mod p cohomology of certain p-groups. More precisely we look at central Frattini extensions of elementary abelian by elementary abelian groups such that their defining k-invariants span the entire image of the Bockstein. We show that if p is sufficiently large, then the mod p cohomology of the extension can be explic

Andrew Ranicki

This paper is an introduction to the use of the cobordism of chain complexes with Poincaré duality in surgery theory. It is a companion to the author&#39;s paper &#34;An introduction to algebraic surgery&#34; math.AT/0008071 (to appear in Volume 2 of Surveys in Surgery Theory, Ann. of Maths. Studies, Princeton, 2001) which is an introduction to algebraic sur

J. Ding, S. Khoroshkin, S. Pakuliak

The factorization of the universal R-matrix corresponding to so called Drinfeld Hopf structure is described on the example of quantum affine algebra $U_q(\hat{sl}_2)$. As a result of factorization procedure we deduce certain differential equations on the factors of the universal ${\cal R}$-matrix, which allow to construct uniquely these factors in the integr

J. Ding, S. Khoroshkin, S. Pakuliak

We present an integral formula for the universal R-matrix of quantum affine algebra with &#39;Drinfeld comultiplication&#39;. We show that the properties of the universal R-matrix follow from the factorization properties of the cycles in proper configuration spaces. For general g we conjecture that such cycles exist and unique. For $U_q(\hat{sl}_2)$ describe

Juan Jose Garcia-Ripoll, Victor M. Perez-Garcia

In this paper we study the application of the Sobolev gradients technique to the problem of minimizing several Schrödinger functionals related to timely and difficult nonlinear problems in Quantum Mechanics and Nonlinear Optics. We show that these gradients act as preconditioners over traditional choices of descent directions in minimization methods and show

Henry Cohn

We study the 2-adic behavior of the number of domino tilings of a 2n-by-2n square as nvaries. It was previously known that this number was of the form 2^n f(n)^2, where f(n) is an odd, positive integer. We show that the function f is uniformly continuous under the 2-adic metric, and thus extends to a function on all of Z. The extension satisfies the function

Henry Cohn

We study explicit continued fraction expansions for certain series. Some of these expansions have symmetry that generalizes some remarkable examples discovered independently by Kmosek and Shallit. Furthermore, we prove the following theorem: Suppose f(x) is a polynomial with integer coefficients, and consider the sum of 1/f^n(x) as n goes from 0 to infinity,

Michael K. Kinyon, Kenneth Kunen, J. D. Phillips

An A-loop is a loop in which every inner mapping is an automorphism. We settle a problem which had been open since 1956 by showing that every diassociative A-loop is Moufang.

Paul Seidel, R. P. Thomas

This paper gives a construction of braid group actions on the derived category of coherent sheaves on a variety $X$. The motivation for this is Kontsevich&#39;s homological mirror conjecture, together with the occurrence of certain braid group actions in symplectic geometry. One of the main results is that when $\dim X \geq 2$, our braid group actions are al

R. Arnowitt, B. Dutta

The general structure of the matter Kahler metric in the $κ^{2/3}$ expansion of Horava-Witten M-theory with nonstandard embeddings is examined. It is shown that phenomenological models based on this structure can lead to Yukawa and V$_{\rm CKM}$ hierarchies (consistent with all data) without introducing ad hoc small parameters if the 5-branes lie near the di

E. Corrigan, A. Taormina

The investigation of boundary breather states of the sinh-Gordon model restricted to a half-line is revisited. Properties of the classical boundary breathers for the two-parameter family of integrable boundary conditions are reviewed and extended. The energy spectrum of the quantized boundary states is computed, firstly by using a bootstrap technique and, su

L. Martinovic, J. P. Vary

Spontaneous chiral symmetry breaking and axial anomaly are studied in the light-front formulation. The existence of multiple vacua and a Nambu-Goldstone boson, both related to dynamical fermion zero modes, are demonstrated within a simple sigma model with fermions. The Weyl gauge formulation and a consistent gauge invariant point-splitting regularization, wh

Lars Kjaergaard

The exact renormalisation group equation is studied for a two-dimensional theory with exponential interaction and a background charge at infinity. The motivation for studying this interaction is the flow between unitary minimal models perturbed by Phi_{(1,3)}, and their realisation in terms of a quantum group restricted sine-Gordon model.

Qi-Keng Lu, Zhe Chang, Han-Ying Guo

The Poisson kernels and relations between them for a massive scalar field in a unit ball $B^n$ with Hua&#39;s metric and conformal flat metric are obtained by describing the $B^n$ as a submanifold of an $(n+1)$-dimensional embedding space. Global geometric properties of the AdS space are discussed. We show that the $(n+1)$-dimensional AdS space AdS$_{n+1}$ i

Bo-Qiang Ma

The recent progress in the investigations on the quark structure of the $Λ$ and $Σ$ baryons are reviewed. It is shown that the quark structure of $Λ$ and $Σ$ hyperons can provide a new domain to test various theories concerning the spin and flavor structure of the nucleon. The $Λ$ and $Σ$ Physics might be new directions to explore the quark distributions of

S. T. Tsou, H. M. Chan

A new category of phenomena is predicted in which fermions of different flavours can transmute into one another, for example $e \to μ$ or $e \to τ$, as a consequence of the `rotating&#39; mass matrix due to renormalization. As examples, calculations will be presented for various such processes. Some of these could be accessible to experiments in the near fut

Ulrich Nierste, Tilman Plehn

We discuss recently reported experimental hints for a bottom squark with mass around 3.5 GeV decaying as sbottom -> charm + lepton + anti-sneutrino. We correlate the sbottom lifetime with the decay rates for bottom -> sbottom + neutrino + anti-sneutrino and bottom -> sbottom + anti-neutrino + sneutrino in the framework of a minimal supersymmetric model exten

Michael McNeil Forbes, Ariel R. Zhitnitsky

In this paper, we propose a mechanism to generate large-scale magnetic fields with correlations lengths of 100 kpc. Domain walls with QCD scale internal structure form and coalesce obtaining Hubble size correlations and align nucleon spins. Due to strong CP violation, nucleons in these walls have anomalous electric and magnetic dipole moments and thus the wa

Yu. S. Surovtsev, D. Krupa, M. Nagy

On the basis of a simultaneous description of the isoscalar s-wave channel of the $ππ$ scattering (from the threshold up to 1.9 GeV) and of the $ππ\to K\bar{K}$ process (from the threshold to $\sim$ 1.4 GeV) in the model-independent approach, a confirmation of the $σ$-meson at $\sim$ 665 MeV and an indication for the glueball nature of the $f_0(1500)$ state

T. Heinzl

The light-cone wave function of the pion is calculated within the Nambu-Jona-Lasinio model. The result is used to derive the pion electromagnetic form factor, charge radius, structure function, pi-gamma transition form factor and distribution amplitude.

S. T. Tsou

Fermion mass matrices generally rotate in generation space under scale changes, which can lead to fermions of different generations transmuting into one another. The effect is examined in detail and its cross-section calculated for $γ+ \ell_α\longrightarrow γ+ \ell_β$ with $\ell_α\neq \ell_β$ the charged leptons $e, μ$, or $τ$. For the (conventional) Standar

H. M. Chan, S. T. Tsou

A solution to the generation puzzle based on a nonabelian generalization of electric-magnetic duality is briefly reviewed. It predicts 3 and only 3 generations of fermions and explains the hierarchical mass spectrum as well as the main features in both the quark and lepton mixing matrices. A calculation to leading perturbative order already gives reasonable

Lorenzo Magnea

The resummed expression for the quark form factor illustrates the fact that dimensional continuation provides a regularization not only for ultraviolet and infrared singularities of fixed order QCD amplitudes, but also for the Landau pole arising in resummed calculations. Explicit renormalization group invariant analytic expressions for the logarithm of the

D. Colferai

Starting from a rewiev of DGLAP and BFKL evolution equations for small-x processes, a sistematic study is performed in order to understand the limits of both the formulations and to improve them in a unique framework, which aims to cover the whole range of applicability of perturbative QCD and which describes the transition mechanism from perturbative to non

Nora Brambilla

Heavy quark bound state systems, mesons and hybrids, are discussed in the framework of the QCD effective field theory called potential Non-Relativistic QCD.

Kurt Langfeld, Alexandra Schafke

The c-vortex ensembles are constructed by means of the recently proposed cooling method which gradually removes the SU(2)/Z_2 coset fields from the SU(2) lattice configurations and which thus reveals the Z_2 vortex vacuum texture. Using Teper&#39;s blocking method, the screening masses of the 0+ and the 2+ glueball is calculated from these vortex ensembles a

Jeffrey A. Appel, Charles N. Brown, Peter S. Cooper, Herman B. White

This document is an abridgement of the commemorative book prepared on the occasion of the symposium &#34;In Celebration of the Fixed Target Program with the Tevatron&#34; held at Fermilab on June 2, 2000. The full text with graphics contains, in addition to the material here, a section for each experiment including a &#34;plain text&#34; description, lists o

A. Benvenuti, D. Denegri, V. Genchev, A. Khanov

For most physical processes the tracks observed in the muon stations must be matched with the corresponding tracks in the inner tracker, the external muon system providing muon identification and triggering but the tracker points giving the precise momentum measurement at lower momenta. For high momenta the momentum resolution is much improved by the interco

H. Adarkar, S. R. Dugad, M. R. Krishnaswamy, M. G. K. Menon

Deep underground in Kolar Gold Fields, in southern India, an experiment to detect proton decay had been carried out since the end of 1980. Analysis of data yielded the following results; (l) the life time of proton is about 1 x 1031 years, (2) it decays into wide spectrum of decay modes, p -> e+ + pai0, p ->anti-nutrino + K+ and so on, and (3) the life time

F. Atchison, M. Daum, P. -R. Kettle, C. Wigger

The time anomaly of neutrino events observed in the KARMEN detector at the ISIS facility is discussed. We show that beam-correlated neutron events are not completely suppressed by the KARMEN lower energy cut and could cause the observed deviation of the measured time distribution from an exponential curve with tau = 2.2 microseconds.

Luc Blanchet, Sergei Kopeikin, Gerhard Schäfer

The paper gives an introduction to the gravitational radiation theory of isolated sources and to the propagation properties of light rays in radiative gravitational fields. It presents a theoretical study of the generation, propagation, back-reaction, and detection of gravitational waves from astrophysical sources. After reviewing the various quadrupole-mome

Stefan Riezler

In this thesis, we present two approaches to a rigorous mathematical and algorithmic foundation of quantitative and statistical inference in constraint-based natural language processing. The first approach, called quantitative constraint logic programming, is conceptualized in a clear logical framework, and presents a sound and complete system of quantitativ

Detlef Prescher, Stefan Riezler, Mats Rooth

This paper presents the use of probabilistic class-based lexica for disambiguation in target-word selection. Our method employs minimal but precise contextual information for disambiguation. That is, only information provided by the target-verb, enriched by the condensed information of a probabilistic class-based lexicon, is used. Induction of classes and fi