October 2003 arXiv papers — page 9

Hettithanthrige S. Wijesinghe, Nicolas G. Hadjiconstantinou

We discuss hybrid atomistic-continuum methods for multiscale hydrodynamic applications. Both dense fluid and dilute gas formulations are considered. The choice of coupling method and its relation to the fluid physics is discussed. The differences in hybrid methods resulting from underlying compressible and incompressible continuum formulations as well as the

Guangjun Mao

This paper was withdrawn by the author.

G. Molchan, A. Khokhlov

We consider the paths of a Gaussian random process $x(t)$, $x(0)=0$ not exceeding a fixed positive level over a large time interval $(0,T)$, $T\gg 1$. The probability $p(T)$ of such event is frequently a regularly varying function at $\infty$ with exponent $θ$. In applications this parameter can provide information on fractal properties of processes that are

Raphael Yuster

We prove that every Eulerian orientation of $K_{m,n}$ contains $\frac{1}{4+\sqrt{8}}mn(1-o(1))$ arc-disjoint directed 4-cycles, improving earlier lower bounds. Combined with a probabilistic argument, this result is used to prove that every regular tournament with $n$ vertices contains $\frac{1}{8+\sqrt{32}}n^2(1-o(1))$ arc-disjoint directed 4-cycles. The res

Jian Zhou

We show that the generating series of some Hodge integrals involving one or two partitions are tau-functions of the KP hierarchy or the 2-Toda hierarchy respectively. We also formulate a conjecture on the connection between relative invariants and integrable hierarchies. The conjecture is verified in some examples.

Ilan Hirshberg

We consider C*-algebras generated by a single Hilbert bimodule (Pimsner-Toeplitz algebras) and by a product systems of Hilbert bimodules. We give a new proof of a theorem of Pimsner, which states that any representation of the generating bimodule gives rise to a representation of the Pimsner-Toeplitz algebra. Our proof does not make use of the conditional ex

Alexander Strohmaier

Let X=G/K be a symmetric space of noncompact type and let L be the Laplacian associated with a G-invariant metric on X. We show that the resolvent kernel of L admits a holomorphic extension to a Riemann surface depending on the rank of the symmetric space. This Riemann surface is a branched cover of the complex plane with a certain part of the real axis remo

Paolo Maraner

We emphasize that the group-theoretical considerations leading to SO(10) unification of electro-weak and strong matter field components naturally extend to space-time components, providing a truly unified description of all generation degrees of freedoms in terms of a single chiral spin representation of one of the groups SO(13,1), SO(9,5), SO(7,7) or SO(3,1

H. Ballhausen

Recent work on exact renormalization group flow equations has pointed out the possibility to study critical phenomena in continuous dimension D of space. In an investigation of the O(N) model the dimension N of the fields may be seen as a continuous parameter as well. One may conjecture that a variation of D or N in the vicinity of a second order phase trans

Anindya Biswas, Sudipta Mukherji

The free energies of the conformal field theories dual to charged adS and rotating adS black holes show Hawking-Page phase transition. We study the transition by constructing boundary free energies in terms of order parameters. This is done by employing Landau's phenomenological theory of first order phase transition. The Cardy-Verlinde formula is then s

Noriyuki Oshimo

We show that experimental results for the masses and mixing of the neutrinos can be understood naturally by a simple grand unification model of SU(5) coupled to N=1 supergravity. No right-handed neutrinos are included. The left-handed neutrinos receive Majorana masses through the couplings with a Higgs boson of symmetric $\bf 15$ representation. Introducing

Xuelei Wang, Bingzhong Li, Yueling Yang

In the framework of topcolor-assisted-technicolor model(TC2), we study a flavor-changing neutral top-pion production process $γγ\to t\bar{c}Π_{t}^{0}$. The study shows that there exists a resonance effect which can enhance the cross section up to a few fb even tens fb. For a yearly luminosity 100 $fb^{-1}$ at future linear colliders, there might be hundreds

D. M. Broun, P. J. Turner, G. K. Mullins, D. E. Sheehy

We report microwave surface impedance measurements made on a single crystal of PrOs_4Sb_12 across the frequency range 0.5 to 21 GHz. The penetration depth data provide clear thermodynamic evidence for superconductivity arising in two bands coupled by Josephson pair-tunneling, indicating two order parameters with the same symmetry. Detailed conductivity spect

F. Fazileh, R. J. Gooding, D. C. Johnston

We have studied the composition-induced metal-to-insulator transitions of cation substituted Lithium Titanate, in the forms Li1+xTi2-xO4 and LiAlyTi2-yO4, utilising a quantum site percolation model, and we argue that such a model provides a very reliable representation of the noninteracting electrons in this material if strong correlations are ignored. We th

U. Al Khawaja

We investigate energetic stability of vortices near the surface of a Bose-Einstein condensate. From an energy functional of a rotating Bose-Einstein condensate, written in terms of variables local to the surface, and a suitable trial wavefunction we calculate the energy of a moving vortex. The energetic stability of the vortex is investigated in terms of the

M. Hara, A. Endo, S. Katsumoto, Y. Iye

We have investigated distinctive transport phenomena in two-dimensional electron gas (2DEG) narrow channel subjected to a large magnetic field gradient, a unique situation created in a ferromagnet/2DEG hybrid structure. The so-called snake orbits which propagate in the direction determined by the sign of field gradient, give rise to conductivity enhancement

Panchapakesan Ramanarayanan, Renat F. Sabirianov, Kyeongjae Cho

We present the first principles results of point defect energetics in silicon calculated using the LDA+U method: a Hubbard type on-site interaction added to the local density approximation (LDA). The on-site Coulomb and exchange parameters were tuned to match the experimental band gap in Si. The relaxed configuration was obtained using the LDA; LDA+U was use

Fang Wu, Bernardo A. Huberman

We present a method that allows for the discovery of communities within graphs of arbitrary size in times that scale linearly with their size. This method avoids edge cutting and is based on notions of voltage drops across networks that are both intuitive and easy to solve regardless of the complexity of the graph involved. We additionally show how this algo

Norikazu Todoroki, Seiji Miyashita

We study the ordered phases and the phase transitions in the stacked triangular antiferromagnetic Ising (STAFI) model with strong interplane coupling modeling CsCoCl$_3$ and CsCoBr$_3$. We find that there exists an intermediate phase which consists of a single phase of so-called partial disordered (PD) type, and confirm the stability of this phase. The low t

L. Zampieri, P. Mucciarelli, R. Falomo, P. Kaaret

We present new optical and {\it Chandra} observations of the field containing the ultraluminous X-ray source NGC 1313 X-2. On an ESO 3.6 m image, the {\it Chandra} error box embraces a $R=21.6$ point-like object and excludes a previously proposed optical counterpart. The resulting X-ray/optical flux ratio of NGC 1313 X-2 is $\sim 500$. The value of $f_X/f_{o

Antony A. Stark, Christopher L. Martin, Wilfred M. Walsh, Kecheng Xiao

We have used the Antarctic Submillimeter Telescope and Remote Observatory (AST/RO), a 1.7m diameter single-dish submillimeter-wave telescope at the geographic South Pole, to determine the physical state of gas in the Galactic Center region and assess its stability. We present an analysis based on data obtained as part of an ongoing AST/RO key project: the la

N. A. Inogamov, R. A. Sunyaev

Large-scale bulk motions and hydrodynamic turbulence in the intergalactic gas inside clusters of galaxies significantly broaden X-ray emission lines. For lines of heavy ions (primarily helium-like and hydrogen-like iron ions), the hydrodynamic broadening is significantly larger than the thermal broadening. Since cluster of galaxies have a negligible optical

U. F. Katz

The ANTARES collaboration is constructing a neutrino telescope in the Mediterranean Sea at a depth of 2400 metres, about 40 kilometres off the French coast near Toulon. The detector will consist of 12 vertical strings anchored at the sea bottom, each supporting 25 triplets of optical modules equipped with photomultipliers, yielding sensitivity to neutrinos w

J. R. Bond, C. R. Contaldi, D. Pogosyan

Abbreviated: We highlight the remarkable evolution in the CMB power spectrum over the past few years, and in the cosmological parameters for minimal inflation models derived from it. Grand unified spectra (GUS) show pre-WMAP optimal bandpowers are in good agreement with each other and with the one-year WMAP results, which now dominate the L < 600 bands. GUS

F. Combes, A. -L. Melchior

We have undertaken a large series of numerical simulations with the goal to built a library of galaxy mergers (GALMER). Since the aim is to have more than a thousand of realisations, each individual run is simplified, with a small number of particules (24 000), but following the chemodynamical evolution, with star formation and feedback. We illustrate in thi

Monwhea Jeng

We add a defect line of dissipation, or crack, to the Abelian sandpile model. We find that the defect line renormalizes to separate the two-dimensional plane into two half planes with open boundary conditions. We also show that varying the amount of dissipation at a boundary of the Abelian sandpile model does not affect the universality class of the boundary

W. C. Nunes, W. S. D. Folly, J. P. Sinnecker, M. A. Novak

The magnetic properties of Cu97Co3 and Cu90Co10 granular alloys were measured over a wide temperature range (2 to 300K). The measurements show an unusual temperature dependence of the coercive field. A generalized model is proposed and explains well the experimental behavior over a wide temperature range. The coexistence of blocked and unblocked particles fo

C. C. Cheung

The recent discovery of an X-ray jet in the z=4.3 quasar GB 1508+5714 by Yuan et al. (astro-ph/0309318) and Siemiginowska et al. (astro-ph/0310241) prompted a search for its radio counterpart. Here, we report the successful discovery of faint radio emission from the jet at 1.4 GHz using archival VLA data. The X-ray emission is best interpreted as inverse Com

Maurice R. Kibler

This paper presents two facets. First, we show that the periodic table of chemical elements can be described, understood and modified (as far as its format is concerned) on the basis of group theory and more specifically by using the group SO(4,2)xSU(2). Second, we show that &#34;periodic tables&#34; also exist in the sub-atomic and sub-nuclear worlds and th

Dave Witte Morris

Unipotent flows are well-behaved dynamical systems. In particular, Marina Ratner has shown that the closure of every orbit for such a flow is of a nice algebraic (or geometric) form. After presenting some consequences of this important theorem, these lectures explain the main ideas of the proof. Some algebraic technicalities will be pushed to the background.

Yuhan Lim

A new diffeomorphism invariant of integral homology 3-spheres is defined using a non-abelian &#39;quaternionic&#39; version of the Seiberg-Witten equations.

Igor Nikolaev

We classify the polycyclic totally ordered simple dimension groups, i.e. dimension groups given by a dense embedding of n-dimensional lattice into the real line. Our method is based on the geometry of simple geodesics on the hyperbolic surface of genus greater or equal two. The main theorem says that isomorphism classes of the polycyclic totally ordered dime

Sabrina Leslie, Neil Shenvi, Kenneth R. Brown, Dan M. Stamper-Kurn

The transmission spectrum of a high-finesse optical cavity containing an arbitrary number of trapped atoms is presented. We take spatial and motional effects into account and show that in the limit of strong coupling, the important spectral features can be determined for an arbitrary number of atoms, N. We also show that these results have important ramifica

S. Incerti, Ph. Barberet, R. Villeneuve, P. Aguer

Light-ion microbeams provide a unique opportunity to irradiate biological samples at the cellular level and to investigate radiobiological effects at low doses of high LET ionising radiation. Since 1998 a single-ion irradiation facility has been developed on the focused horizontal microbeam line of the CENBG 3.5 MV Van de Graaff accelerator. This setup deliv

Osvaldo F. Schilling

Oscillators and rotators are among the most important physical systems. For centuries the only known rotating systems that actually reached the limits of the ideal situation of undamped periodical motion were the planets in their orbits. Physics had to develop quantum mechanics to discover new systems that actually behaved like ideal, undamped, oscillators o

M. B. Tsang, T. X. Liu, L. Shi, P. Danielewicz

Using symmetric 112Sn+112Sn, 124Sn+124Sn collisions as references, we probe isospin diffusion in peripheral asymmetric 112Sn+124Sn, 124Sn+112Sn systems at incident energy of E/A=50 MeV. Isoscaling analyses imply that the quasi-projectile and quasi-target in these collisions do not achieve isospin equilibrium, permitting an assessment of the isospin transport

G. Honnouvo, M. N. Hounkonnou

We investigate the two-dimensional magnetic operator $H_{c_0,B,β} = {(-i\nabla -A)}^{2}-βδ(.-Γ),$ where $Γ$ is a smooth loop. The vector potential has the form $A=c_0\bigg(\frac{-y}{x^2+y^2}; \frac{x}{x^2+y^2} \bigg)+ \frac{B}{2}\bigg(-y; x\bigg) $; $B>0,$ $c_0\in]0;1[$. The asymptotics of negative eigenvalues of $H_{c_0,B,β}$ for $β\longrightarrow +\infty$

B. H. Lavenda

Fermat&#39;s principle applied to a flat metric in the plane yields the phase of a Bessel function in the periodic domain for a constant index of refraction. Gravitational forces cause the index of refraction to vary and lead to a modified phase of the Bessel function. A distinction is made between the forces that cause acceleration: the gravitational force

Gong-bao Wamg, Ji-pu Ma

Some new reverses of the Cauchy-Schwarz inequality in inner product spaces are presented in this paper.The results obtained here complement the recent work of the references.

Najmuddin Fakhruddin

We prove the following result: Let B be a smooth, irreducible, quasi-projective variety over the complex numbers and assume that B has a projective compactification \bar{B} such that \bar{B} - B is of codimension at least two in \bar{B}. Then there exists a family of smooth ireducible curves {C_q}_{q \in Q} in B parametrised by an irreducible variety Q such

Kaida Shi

The attributes of Euler&#39;s constant Gamma have been a baffling problem to the world&#39;s mathematicians in the number theory field. In 1900, when German mathematician D. Hilbert addressed the 2nd International Congress of Mathematicians, he suggested twenty-three previously unsolved problems to the international mathematical field. The 7th of these probl

D. M&#34;ulsch, B. GEyer

A formulation of the N_T=1, D=8 Euclidean super Yang-Mills theory with generalized self-duality and reduced Spin(7)-invariance is given which avoids the peculiar extra constraints of Nishino and Rajpoot, hep-th/0210132. Its reduction to 7 dimensions leads to the G_2-invariant N_T=2, D=7 super Yang-Mills theory which may be regarded as a higher-dimensional an

Yujun Chen

In this paper I give an explicit conformal field theory description of (2+1)-dimensional BTZ black hole entropy. In the boundary Liouville field theory I investigate the reducible Verma modules in the elliptic sector, which correspond to certain irreducible representations of the quantum algebra U_q(sl_2) \odot U_{\hat{q}}(sl_2). I show that there are states

Anupam Mazumdar

In this paper we illustrate an interesting example of low scale inflation with an extremely large number of e-foldings. This realization can be implemented easily in hybrid inflation model where usually inflation ends via phase transition. However this phase transition can be so prolong that there is a subsequent epoch of slow roll inflation governed by the

Yoshitaka Okumura

It is well-known that the charge of fermion is 0 or $\pm1$ in the U(1) gauge theory on noncommutative spacetime. Since the deviation from the standard model in particle physics has not yet observed, and so there may be no room to incorporate the noncommutative U(1) gauge theory into the standard model because the quarks have fractional charges. However, it i

Chuan-Hung Chen

We investigate the production of the novel $P$-wave mesons $D^{*}_{0}$ and $D^{\prime}_{1} (D_{1})$, identified as $J^{P}=0^+$ and $1^+$, in heavy $B$ meson decays, respectively. With the heavy quark limit, we give our modelling wave functions for the scalar meson $D^{*}_{0}$. Based on the assumptions of color transparency and factorization theorem, we estim

S. J. Brodsky

The effective QCD charge extracted from $τ$ decay is remarkably constant at small momenta, implying the near-conformal behavior of hadronic interactions at small momentum transfer. The correspondence of large-$N_C$ supergravity theory in higher-dimensional anti-de Sitter spaces with gauge theory in physical space-time also has interesting implications for ha

Shi-Lin Zhu

We estimate the mass of the pentaquark state with QCD sum rules and find that pentaquark states with isospin $I=0, 1, 2$ lie close to each other around $(1.55\pm 0.15)$ GeV. The experimentally observed baryon resonance $Θ^+ (1540)$ with $S=+1$ can be consistently identified as a pentaquark state if its $J^P={1\over 2}^-$. Such a state is expected in QCD. If

V. Batagelj, M. Zaversnik

The structure of large networks can be revealed by partitioning them to smaller parts, which are easier to handle. One of such decompositions is based on $k$--cores, proposed in 1983 by Seidman. In the paper an efficient, $O(m)$, $m$ is the number of lines, algorithm for determining the cores decomposition of a given network is presented.

B. Mehlig, M. Wilkinson

We analyse the motion of a system of particles suspended in a fluid which has a random velocity field. There are coagulating and non-coagulating phases. We show that the phase transition is related to a Kramers problem, and use this to determine the phase diagram, as a function of the dimensionless inertia of the particles, epsilon, and a measure of the rela

B. Jäger, S. Paluch, W. Wolf, P. Herzig

Two compounds, tetragonal YB$_4$ and cubic YB$_6$, have been investigated by electric-field gradient (EFG) and Knight shift measurements at the boron sites using the $^{11}$B nuclear magnetic resonance (NMR) technique and by performing first-principles calculations. In YB$_6$ $^{11}$B ($I=3/2$) NMR spectra reveal patterns typical for an axially symmetric fie

Chao-Hsien Kuo, Zhen Ye

We investigate the electromagnetic propagation in two-dimensional photonic crystals, formed by parallel dielectric cylinders embedded a uniform medium. The transmission of electromagnetic waves through prism structures are calculated by the standard multiple scattering theory. The results demonstrate that in certain frequency regimes and when the propagation

M. Wilkinson, B. Mehlig

A particle subject to successive, random displacements is said to execute a random walk (in position or some other coordinate). The mathematical properties of random walks have been very thoroughly investigated, and the model is used in many areas of science and engineering as well as other fields such as finance and the life sciences. This letter describes

A. A. Prykarpatsky, V. V. Gafiychuk

We consider the general properties of the replicator dynamical system from the standpoint of its evolution and stability. Vector field analysis as well as spectral properties of such system has been studied. Lyaponuv function for investigation of system evolution has been proposed. The generalization of the replicator dynamics for the case of multi-agent sys

Stefan Kehrein, Matthias Vojta

We study a model of Ising-coupled Kondo impurities that can be applied to quantum dots with capacitance coupling, coupled qubits with an incoherent environment, etc. We show that this model becomes equivalent to a Anderson impurity model with a novel solitonic Fermi sea. We derive exact results at the Toulouse point, and use the flow equation method to exten

J. C. Augereau, J. C. B. Papaloizou

Scattered light images of the optically thin dust disk around the 5 Myr old star HD141569 have revealed its complex asymmetric structure. We show in this paper that the surface density inferred from the observations presents similarities with that expected from a circumprimary disk within a highly eccentric binary system. We assume that either the two M star

Anatoly Spitkovsky

I review the theoretical understanding of the global structure of pulsar magnetospheres concentrating on recent progress in force-free electrodynamics and first-principles simulations of magnetospheres.

Dah-Wei Chiou, Ori J. Ganor

We extend the argument of Gomis and Mehen for violation of unitarity in field theories with space-time noncommutativity to dipole field theories. In dipole field theories with a timelike dipole vector, we present 1-loop amplitudes that violate the optical theorem. A quantum mechanical system with nonlocal potential of finite extent in time also shows violati

Bryan Kelleher

Recently a scale invariant theory of gravity was constructed by imposing a conformal symmetry on general relativity. The imposition of this symmetry changed the configuration space from superspace - the space of all Riemannian 3-metrics modulo diffeomorphisms - to conformal superspace - the space of all Riemannian 3-metrics modulo diffeomorphisms and conform

Michael P. Muno, Duncan K. Galloway, Deepto Chakrabarty, ;

Previously, observations with the Rossi X-ray Timing Explorer showed that millisecond oscillations occur preferentially in thermonuclear X-ray bursts with photospheric radius expansion from sources rotating near 600 Hz, while they occur with equal likelihood in X-ray bursts with and without radius expansion for sources rotating near 300 Hz. With a larger sam

R. M. Sambruna, M. Gliozzi, D. Donato, F. Tavecchio

We present an XMM observation of the radio jet and diffuse halo of the nearby radio galaxy NGC6251. The EPIC spectrum of the galaxy&#39;s halo is best-fitted by a thermal model with temperature kT~1.6 keV and subsolar abundances. Interestingly, an additional hard X-ray component is required to fit the EPIC spectra of the halo above 3 keV, and is independentl

Nikolai A. Zarkevich, D. D. Johnson

In alloys cluster expansions (CE) are increasingly used to combine first-principles electronic-structure and Monte Carlo methods to predict thermodynamic properties. As a basis-set expansion in terms of lattice geometrical clusters and effective cluster interactions, the CE is exact if infinite, but is tractable only if truncated. Yet until now a truncation

Martin Kruczenski

We consider supergravity solutions corresponding to D7 branes wrapped on Kahler manifolds with a U(1)_R twist such that some supersymmetry is preserved. We find a class of 1/4-BPS backgrounds where a D7-brane is wrapped on a T^2 torus with a metric of non-constant curvature. Similarly to the flat D7-brane case, the solution has a singularity at finite radius

S. Burciu

Let H be a cosemisimple Hopf algebra over an algebraically closed field k which contains a simple subcoalgebra of dimension 9. We show that if H has no simple subcoalgebras of even dimension then H contains either a grouplike element with order 2 or 3, a Hopf subalgebra of dimension 75, or a family of simple subcoalgebras whose dimensions are the squares of

Thomas Klose, Jan Plefka

We show the three-loop integrability of large N plane-wave matrix theory in a subsector of states comprised of two complex light scalar fields. This is done by diagonalizing the theory&#39;s Hamiltonian in perturbation theory and taking the large N limit. At one-loop level the result is known to be equal to the Heisenberg spin-1/2 chain, which is a well-know

Jordi Miralda-Escude, Juna A. Kollmeier

A new theory of quasars is presented in which the matter of thin accretion disks around black holes is supplied by stars that plunge through the disk. Stars in the central part of the host galaxy are randomly perturbed to highly radial orbits, and as they repeatedly cross the disk they lose orbital energy by drag, eventually merging into the disk. Requiring

Makoto Sakaguchi, Kentaroh Yoshida

We consider D-branes of open superstrings in the AdS_5 x S^5 background. The possible configurations of D-branes preserving half of supersymmetries are classified by analyzing the kappa-invariance of an open superstring in a covariant manner. We also revisit the classification of D-branes in the pp-wave background. It is shown that Penrose limits of the poss

Joao Faria Martins

We analyse the possibility of defining complex valued Knot invariants associated with infinite dimensional unitary representations of $SL(2,R)$ and the Lorentz Group taking as starting point the Kontsevich Integral and the notion of infinitesimal character. This yields a family of knot invariants whose target space is the set of formal power series in $C$, w

The BABAR Collaboration, B. Aubert

A narrow state, which we label DsJ(2458)+, with mass 2458.0 +/- 1.0(stat.) +/- 1.0(syst.) MeV/c^2, is observed in the inclusive Ds+ pi0 γ$ mass distribution in 91 fb-1 of e^+e^- annihilation data recorded by the BABAR detector at the PEP-II asymmetric-energy e^+e^- storage ring. The observed width is consistent with the experimental resolution. The data favo

Silvia Mollerach, Diego Harari, Sabino Matarrese

We consider a novel contribution to the polarization of the Cosmic Microwave Background induced by vector and tensor modes generated by the non-linear evolution of primordial scalar perturbations. Our calculation is based on relativistic second-order perturbation theory and allows to estimate the effects of these secondary modes on the polarization angular p

V. Gritsev, B. Normand, D. Baeriswyl

We investigate the phase diagram of a generalized spin-1/2 quantum antiferromagnet on a ladder with rung, leg, diagonal, and ring-exchange interactions. We consider the exactly soluble models associated with the problem, obtain the exact ground states which exist for certain parameter regimes, and apply a variety of perturbative techniques in the regime of s

W. Nahm, D. H. Tchrakian

We investigate $4+d$ dimensional fermionic models in which the system in codimension-$d$ supports a topologically stable solution, and in which the fermion may be localised to the brane, with power law in &#39;instanton&#39; backgrounds and exponentially in &#39;soliton&#39; backgrounds. When the fermions are isoscalars, the mechanism fails, while for isospi

Pierre Grange, Ernst Werner

In Continuum Light Cone Quantization (CLCQ) the treatment of scalar fields as operator valued distributions and properties of the accompanying test functions are recalled. Due to the paracompactness property of the Euclidean manifold these test functions appear as decomposition of unity. The approach is extended to QED Dirac fields in a gauge invariant way.

Lis Brack-Bernsen, Matthias Brack

We investigate ``shell structure&#39;&#39; from Babylonian times: periodicities and beats in computer-simulated lunar data corresponding to those observed by Babylonian scribes some 2500 years ago. We discuss the mathematical similarity between the Babylonians&#39; recently reconstructed method of determining one of the periods of the moon with modern Fourie

D. Valenti, A. Fiasconaro, B. Spagnolo

We study the role of the noise in the dynamics of two competing species. We consider generalized Lotka-Volterra equations in the presence of a multiplicative noise, which models the interaction between the species and the environment. The interaction parameter between the species is a random process which obeys a stochastic differential equation with a gener

Aiguo Xu, G. Gonnella, A. Federici, S. Stramaglia

Two mathematical methods, the Fourier and wavelet transforms, were used to study the short term cardiovascular control system. Time series, picked from electrocardiogram and arterial blood pressure lasting 6 minutes, were analyzed in supine position (SUP), during the first (HD1), and the second parts (HD2) of $90^{\circ}$ head down tilt and during recovery (

A. N. Antonov, M. K. Gaidarov, D. N. Kadrev, P. E. Hodgson

Charge form factors corresponding to proton density distributions in exotic nuclei, such as $^{6,8}$He, $^{11}$Li, $^{17,19}$B and $^{14}$Be are calculated and compared. The results can be used as tests of various theoretical models for the exotic nuclei structure in possible future experiments using a colliding electron-exotic nucleus storage ring. The resu

P. Büttiker, S. Descotes-Genon, B. Moussallam

With the aim of generating new constraints on the OZI suppressed couplings of chiral perturbation theory a set of six equations of the Roy and Steiner type for the $S$- and $P$-waves of the $πK$ scattering amplitudes is derived. The range of validity and the multiplicity of the solutions are discussed. Precise numerical solutions are obtained in the range $E

R. Aguado, T. Brandes

We study the current noise spectrum of qubits under transport conditions in a dissipative bosonic environment. We combine (non-)Markovian master equations with correlation functions in Laplace-space to derive a noise formula for both weak and strong coupling to the bath. The coherence-induced reduction of noise is diminished by weak dissipation and/or a larg

Ch. Siedschlag, J. M. Rost

We develop a microscopic model for the interaction of small rare gas clusters with soft X-ray radiation. It is shown that, while the overall charging of the clusters is rather low, unexpectedly high atomic charge states can arise due to charge imbalances inside the cluster. The mechanism does not require unusually high absorption rates, and the heating can b

S. J. Brodsky, G. F. de Teramond

A remarkable consequence of the AdS/CFT correspondence is the nonperturbative derivation of dimensional counting rules for hard scattering processes. Using string/gauge duality we derive the QCD power behavior of light-front Fock-state hadronic wavefunctions for hard scattering in the large-$r$ region of the AdS space from the conformal isometries which dete

Fan Chung, Joshua N. Cooper

A de Bruijn covering code is a q-ary string S so that every q-ary string is at most R symbol changes from some n-word appearing consecutively in S. We introduce these codes and prove that they can have length close to the smallest possible covering code. The proof employs tools from field theory, probability, and linear algebra. We also prove a number of ``s

F. Benatti, R. Floreanini, M. Piani, R. Romano

After reviewing the main properties of time-evolutions of open quantum systems, some considerations about the positivity of factorized Markovian dynamics for bipartite systems are made. In particular, it is shown that the positivity of the whole time-evolution in general does not ask for the complete positivity of the single system time-evolutions, if they a

Stephen D. Bartlett, Barry C. Sanders

We identify &#34;proper quantum computation&#34; with computational processes that cannot be efficiently simulated on a classical computer. For optical quantum computation, we establish &#34;no-go&#34; theorems for classes of quantum optical experiments that cannot yield proper quantum computation, and we identify requirements for optical proper quantum comp

Anna L. Lin, Bernward A. Mann, Gelsy Torres-Oviedo, Bryan Lincoln

The transition from localized to systemic spreading of bacteria, viruses and other agents is a fundamental problem that spans medicine, ecology, biology and agriculture science. We have conducted experiments and simulations in a simple one-dimensional system to determine the spreading of bacterial populations that occurs for an inhomogeneous environment unde

Rodrick Wallace, Deborah Wallace

Generalized language-of-thought arguments appropriate to interacting cognitive modules permit exploration of how disease states interact with medical treatment. The interpenetrating feedback between treatment and response to it creates a kind of idiotypic hall-of-mirrors generating a synergistic pattern of efficacy, treatment failure, adverse reactions, and

Sven Menke

In 2002 the first combined beam test of the hadronic and electromagnetic liquid-argon endcap calorimeters of the ATLAS experiment took place at the SPS test beam at CERN. A total of 15 million events from electrons, muons and pions in the energy range from 6 to 200 GeV were recorded. The entire calibration chain, from digital filter weights, over calibration

J. Miyamoto, I. Shipsey, C. J. Martoff, M. Katz-Hyman

The first operation of GEM gas gain elements in negative ion gas mixtures is reported. Gains up to several thousand were obtained from single-stage GEMs in carbon disulfide vapor at low pressure, and in mixtures of carbon disulfide with Argon and Helium, some near 1 bar total pressure.

A. Andronic

We present measurements of the energy loss of pions and electrons in drift chambers operated with a Xe,CO2(15%) mixture. The measurements are carried out for particle momenta from 1 to 6 GeV/c using prototype drift chambers for the ALICE TRD. Microscopic calculations are performed using input parameters calculated with GEANT3. These calculations reproduce we

C. Ticknor, C. A. Regal, D. S. Jin, J. L. Bohn

We report a unique feature of magnetic field Feshbach resonances in which atoms collide with non-zero orbital angular momentum. P-wave ($l=1$) Feshbach resonances are split into two components depending on the magnitude of the resonant state&#39;s projection of orbital angular momentum onto the field axis. This splitting is due to the magnetic dipole-dipole

Jason D. Holt, T. T. S. Kuo, G. E. Brown

Using a Schmidt orthogonalization transformation, a family of Hermitian low-momentum NN interactions is derived from the non-Hermitian Lee-Suzuki (LS) low-momentum NN interaction. As special cases, our transformation reproduces the Hermitian interactions for Okubo and Andreozzi. Aside from their common preservation of the deuteron binding energy, these Hermi

V. A. Karmanov, J. Carbonell

For zero-range interaction providing a given mass M_2 of the two-body bound state, the mass M_3 of the relativistic three-body bound state is calculated. We have found that the three-body system exists only when M_2 is greater than a critical value M_c (approx. 1.43m for bosons and approx. 1.35m for fermions, m is the constituent mass). For M_2=M_c the mass

R. S. Azevedo, M. Nielsen

We calculate the cross section for the dissociation of $J/ψ$ by kaons within the framework of a meson exchange model including anomalous parity interactions. Off-shell effects at the vertices were handled with QCD sum rule estimates for the running coupling constants. The total $J/ψ$-kaon cross section was found to be $1.0 \sim1.6$ mb for $4.1\leq\sqrt{s}\le

Martin Kotulla

The reaction $γp \to π^0 π^0 p$ has been measured using the TAPS BaF$_2$ calorimeter at the tagged photon facility of the Mainz Microtron accelerator in the beam energy range from threshold up to 820 MeV. Close to threshold, chiral perturbation theory (ChPT) predicts that this channel is significantly enhanced compared to double pion final states with charge

Albert Ferrando, Mario Zacares, Pedro Fernandez de Cordoba, Daniele Binosi

We demonstrate the existence of vortex soliton solutions in photonic crystal fibers. We analyze the role played by the photonic crystal fiber defect in the generation of optical vortices. An analytical prediction for the angular dependence of the amplitude and phase of the vortex solution based on group theory is also provided. Furthermore, all the analysis

L. Martínez Alonso, A. B. Shabat

We present a theory of compatible differential constraints of a hydrodynamic hierarchy of infinite-dimensional systems. It provides a convenient point of view for studying and formulating integrability properties and it reveals some hidden structures of the theory of integrable systems. Illustrative examples and new integrable models are exhibited.

Xin-Chu Fu, Peter Ashwin

In this paper a class of linear maps on the 2-torus and some planar piecewise isometries are discussed. For these discontinuous maps, by introducing codings underlying the map operations, symbolic descriptions of the dynamics and admissibility conditions for itineraries are given, and explicit expressions in terms of the codings for periodic points are prese

Patrik L. Ferrari, Michael Praehofer, Herbert Spohn

We discuss the space-time determinantal random field which arises for the PNG model in one dimension and resembles the one for Dyson&#39;s Brownian motion. The information of interest for growth processes is carried by the edge statistics of the random field and therefore their universal scaling is related to the edge properties of Gaussian multi-matrix mode

Michael A. Dritschel, Scott McCullough

For R a bounded triply connected domain with boundary consisting of disjoint Jordan loops there exists an operator T on a complex Hilbert space H so that the closure of R is a spectral set for T, but T does not dilate to a normal operator with spectrum in B, the boundary of R. There is considerable overlap with the construction of an example on such a domain

Daniel M. Pellegrino

In this paper we present new characterizations of Banach spaces whose duals are isomorphic to $l_{1}(Γ),$ extending results of Stegall, Lewis-Stegall and Cilia-D&#39;Anna-Gutiérrez.