April 2006 arXiv papers — page 39

L. DiCarlo, Y. Zhang, D. T. McClure, C. M. Marcus

We describe the construction and operation of a two-channel noise detection system for measuring power and cross spectral densities of current fluctuations near 2 MHz in electronic devices at low temperatures. The system employs cryogenic amplification and fast-Fourier-transform based spectral measurement. The gain and electron temperature are calibrated usi

O. Cornejo-Perez, J. Negro, L. M. Nieto, H. C. Rosu

Travelling-wave solutions of the standard and compound form of Korteweg-de Vries-Burgers equations are found using factorizations of the corresponding reduced ordinary differential equations. The procedure leads to solutions of Bernoulli equations of nonlinearity 3/2 and 2 (Riccati), respectively. Introducing the initial conditions through an imaginary phase

Hisato Eguchi, Yuji Koike, Kazuhiro Tanaka

We study the single spin asymmetry (SSA) for the pion production with large transverse momentum p_T in semi-inclusive deep inelastic scattering $ep^\uparrow\to eπX$. We derive the twist-3 cross section formula for SSA, focussing on the soft-gluon-pole contributions associated with the twist-3 distribution for the nucleon and with the twist-3 fragmentation fu

Rebecca Hihinashvili, Tali Oliker, Yaniv S. Avizrats, Alexander Iomin

The phase diagram of a simple area-preserving map, which was motivated by the quantum dynamics of cold atoms, is explored analytically and numerically. Periodic orbits of a given winding ratio are found to exist within wedge-shaped regions in the phase diagrams, which are analogous to the Arnol'd tongues which have been extensively studied for a variety

Scott Aaronson

This paper introduces a new technique for removing existential quantifiers over quantum states. Using this technique, we show that there is no way to pack an exponential number of bits into a polynomial-size quantum state, in such a way that the value of any one of those bits can later be proven with the help of a polynomial-size quantum witness. We also sho

M. Lombardi, A. Matzkin

The generation of entanglement produced by a local potential interaction in a bipartite system is investigated. The degree of entanglement is contrasted with the underlying classical dynamics for a Rydberg molecule (a charged particle colliding on a kicked top). Entanglement is seen to depend on the structure of classical phase-space rather than on the globa

A. M. Lisewski

We present a modal logic based approach to the so-called endophysical quantum universe. In particular, we treat the problem of preferred bases and that of state reduction by employing an eclectic collection of methods including Baltag's analytic non-wellfounded set theory, a modal logic interpretation of Dempster-Shafer theory, and results from the theor

A. J. McKane, J. D. Nagy, T. J. Newman, M. O. Stefanini

We describe a mechanism for pronounced biochemical oscillations, relevant to microscopic systems, such as the intracellular environment. This mechanism operates for reaction schemes which, when modeled using deterministic rate equations, fail to exhibit oscillations for any values of rate constants. The mechanism relies on amplification of the underlying sto

A. M. Costa, M. C. Martins, J. P. Santos, Paul Indelicato

Energies and transition probabilities of K$β$ hypersatellite lines are computed using the Dirac-Fock model for several values of $Z$ throughout the periodic table. The influence of the Breit interaction on the energy shifts from the corresponding diagram lines and on the K$β\_{1}^{\rm h}$/K$β\_{3}^{\rm h}$ intensity ratio is evaluated. The widths of the doub

J. P. Marques, F. Parente, M. C. Martins, Paul Indelicato

L$β\_2$ X-ray satellite spectra of tungsten and gold are calculated using the Multi-Configuration Dirac-Fock energies and compared with recent experimental data. New calculations of L$\_1$-L$\_3$M$\_5$ Coster-Kronig transition energies for tungsten are presented, confirming the origin of the L$β\_2$ visible satellites reported by two experimental groups. We

R. Schuch, E. Lindroth, S. Madzunkov, M. Fogle

Longstanding problems in the comparison of very accurate hyperfine-shift measurements to theory were partly overcome by precise measurements on few-electron highly-charged ions. Still the agreement between theory and experiment is unsatisfactory. In this paper, we present a radically new way of precisely measuring hyperfine shifts, and demonstrate its effect

Rajesh G. Kavasseri

In this paper, we study the dynamics and stability of a fundamental power system model when a time delay is imposed on the excitation of the generator. It is observed that sustained oscillations can arise in an otherwise stable power system through a delay induced Andronov-Hopf bifurcation. Numerical simulations are conducted to explore the dynamics of the t

V. S. Gerdjikov

Brief review of the methods for solving the multicomponent nonlinear Schrodinger (MNLS) equations and analysis of their Hamiltonian structures is given. Main attention is paid to the MNLS related to the C.II- and D.III-types symmetric spaces with nonvanishing (constant) boundary conditions. The spectral properties of their Lax operators are described. The de

Vladimir S. Gerdjikov

This is a review of the main ideas of the inverse scattering method (ISM) for solving nonlinear evolution equations (NLEE), known as soliton equations. As a basic tool we use the fundamental analytic solutions (FAS) of the Lax operator L. Then the inverse scattering problem for L reduces to a Riemann-Hilbert problem. Such construction cab be applied to wide

Stefan Hougardy, Frank H. Lutz, Mariano Zelke

We give coordinate-minimal geometric realizations in general position for 17 of the 20 vertex-minimal triangulations of the orientable surface of genus 3 in the 5x5x5-cube.

V. -B. K. Rogov

The connections between q-Bessel functions of three types and q-exponential of three types are established. The q-exponentials and the q-Bessel functions are represented as the Laurent series. The asymptotic behaviour of the q-exponentials and the q-Bessel functions is investigated.

Zoran Sunic

A connection relating Tamari lattices on symmetric groups regarded as lattices under the weak Bruhat order to the positive monoid P of Thompson group F is presented. Tamari congruence classes correspond to classes of equivalent elements in P. The two well known normal forms in P correspond to endpoints of intervals in the weak Bruhat order that determine the

Lilibeth Dicuangco, Pieter Moree, Patrick Sole

Split group codes are a class of group algebra codes over an abelian group. They were introduced in 2000 by Ding, Kohel and Ling as a generalization of the cyclic duadic codes. For a prime power q and an abelian group G of order n such that n and q are coprime, consider the group algebra F_{q^2}[G^{*}] of F_{q^2} over the dual group G^{*} of G. We prove that

Farkhod Eshmatov

Associated to each finite group $Γ$ in $SL_2(C)$ there is a family of noncommutative algebras which deforms the coordinate ring of the Kleinian singularity corresponding to that group. These algebras were defined by W. Crawley-Boevey and M. Holland, who also suggested a conjectural correspondence between the set of isomorphism classes of rank one projective

Jun Hu

We use Naito-Sagaki's work [S. Naito & D. Sagaki, J. Algebra 245 (2001) 395--412, J. Algebra 251 (2002) 461--474] on Lakshmibai-Seshadri paths fixed by diagram automorphisms to study the partitions fixed by Mullineux involution. We characterize the set of Mullineux-fixed partitions in terms of crystal graphs of basic representations of twisted affine Lie

Man-Duen Choi, David W. Kribs, Karol Zyczkowski

We consider higher-rank versions of the standard numerical range for matrices. A central motivation for this investigation comes from quantum error correction. We develop the basic structure theory for the higher-rank numerical ranges, and give a complete description in the Hermitian case. We also consider associated projection compression problems.

Frank H. Lutz

We discuss different approaches for the enumeration of triangulated surfaces. In particular, we enumerate all triangulated surfaces with 9 and 10 vertices. We also show how geometric realizations of orientable surfaces with few vertices can be obtained by choosing coordinates randomly.

E. Goudzovski

A precise measurement of the direct CP violating charge asymmetry parameter $A_g$ in $K^\pm\toπ^\pmπ^+π^-$ decays by the NA48/2 experiment at CERN SPS is presented. The experiment has been designed not to be limited by systematic uncertainties in the asymmetry measurement. A preliminary result for the charge asymmetry $A_g=(-1.3\pm2.3)\times 10^{-4}$ has bee

Alexander V. Evako

Motivated by the Poincare conjecture, we study properties of digital n-dimensional spheres and disks, which are digital models of their continuous counterparts. We introduce homeomorphic transformations of digital manifolds, which retain the connectedness, the dimension, the Euler characteristics and the homology groups of manifolds. We find conditions where

Petrus H. Potgieter

The Mandelbrot set is an extremely well-known mathematical object that can be described in a quite simple way but has very interesting and non-trivial properties. This paper surveys some results that are known concerning the (non-)computability of the set. It considers two models of decidability over the reals (which have been treated much more thoroughly an

Andrei Lopatenko, Leopoldo Bertossi

Consistent Query Answering (CQA) is the problem of computing from a database the answers to a query that are consistent with respect to certain integrity constraints that the database, as a whole, may fail to satisfy. Consistent answers have been characterized as those that are invariant under certain minimal forms of restoration of the database consistency.

Stéphane Marcet, David Ferrand, David Halley, Shinji Kuroda

We report on the magneto-optical spectroscopy and cathodoluminescence of a set of wurtzite (Ga,Mn)N epilayers with a low Mn content, grown by molecular beam epitaxy. The sharpness of the absorption lines associated to the Mn$^{3+}$ internal transitions allows a precise study of its Zeeman effect in both Faraday and Voigt configurations. We obtain a good agre

Oleg Derzhko, Johannes Richter

We study the low-temperature thermodynamic properties of a number of frustrated quantum antiferromagnets which support localized magnon states in the vicinity of the saturation field. For this purpose we use 1) a mapping of the low-energy degrees of freedom of spin systems onto the hard-core object lattice gases and 2) an exact diagonalization of finite spin

Farid El Gabaly, Silvia Gallego, Carmen Munoz, Laszlo Szunyogh

By means of spin-polarized low-energy electron microscopy (SPLEEM) we show that the magnetic easy-axis of one to three atomic-layer thick cobalt films on ruthenium crystals changes its orientation twice during deposition: one-monolayer and three-monolayer thick films are magnetized in-plane, while two-monolayer films are magnetized out-of-plane, with a Curie

M. J. Page, N. S. Loaring, T. Dwelly, K. O. Mason

We present the X-ray spectra of 86 optically-identified sources in the 13H XMM-Newton/Chandra deep field which have >70 X-ray counts. The sample consists of 50 broad line AGN, 25 narrow emission line galaxies, 6 absorption line galaxies, and 5 Galactic stars. The majority (42/50) of the broad line AGN have X-ray spectra which are consistent with a power law

Massimo Giovannini

Large-scale magnetic fields can affect scalar cosmological perturbations whose evolution is described in the conformally Newtonian gauge and within the tight coupling approximation. The magnetized curvature perturbations present after matter radiation equality (and prior to decoupling) are computed in terms of an appropriate transfer matrix allowing a genera

Douglas Scott, Ali Frolop

The now standard vanilla-flavoured LambdaCDM model has gained further confirmation with the release of the 3-year WMAP data combined with several other cosmological data-sets. As the parameters of this standard model become known with increasing precision, more of its bizarre features become apparent. Here we describe some of the strangest of these ostensibl

O. Ilbert, S. Lauger, L. Tresse, V. Buat

We have computed the evolution of the rest-frame B-band luminosity function (LF) for bulge and disk-dominated galaxies since z=1.2. We use a sample of 605 spectroscopic redshifts with I_{AB}<24 in the Chandra Deep Field South from the VIMOS-VLT Deep Survey, 3555 galaxies with photometric redshifts from the COMBO-17 multi-color data, coupled with multi-color

Antony Lewis

I discuss the extraction of cosmological parameter constraints from the recent WMAP 3-year data, both on its own and in combination with other data. The large degeneracies in the first year data can be largely broken with the third year data, giving much better parameter constraints from WMAP alone. The polarization constraint on the optical depth is crucial

P. Manimaran, Prasanta K. Panigrahi, Jitendra C. Parikh

We study the scaling behavior of the fluctuations, as extracted through wavelet coefficients based on discrete wavelets. The analysis is carried out on a variety of physical data sets, as well as Gaussian white noise and binomial multi-fractal model time series and the results are compared with continuous wavelet based average wavelet coefficient method. It

J. Keeling, I. Klich, L. S. Levitov

A strategy is proposed to excite particles from a Fermi sea in a noise-free fashion by electromagnetic pulses with realistic parameters. We show that by using quantized pulses of simple form one can suppress the particle-hole pairs which are created by a generic excitation. The resulting many-body states are characterized by one or several particles excited

L. Pompeia, V. Hill, M. Spite, A. Cole

The advent of the new class 8 meters telescopes allows for the first time the detailed study of numerous stars of galaxies other than our own. The Large Magellanic Cloud is one of the most interesting targets due to its proximity and its relatively face-on disk, permitting to separate populations pertaining to the different structures of the galaxy. We have

M. L. MIller

We present preliminary measurements of the inclusive jet cross section in the transverse momentum region 5<$p_{T}$<50 GeV/\textit{c} from 0.2 $pb^{-1}$ of polarized p+p data at $\sqrt{s}$=200 GeV. The data were corrected for detector inefficiency and resolution using PYTHIA events processed through a full GEANT simulation. The measured jet cross section agre

Andreas Aste

I comment on Ulvi Yurtsever&#39;s result, which states that the entropy of a truncated bosonic Fock space is given by a holographic bound when the energy of the Fock states is constrained gravitationally. The derivation given in Yurtsever&#39;s paper contains an subtle mistake, which invalidates the result. A more restrictive, non-holographic entropy bound i

P Ajith, M Hewitson, I S Heng

Time-series data from multiple gravitational wave (GW) detectors can be linearly combined to form a null-stream, in which all GW information will be cancelled out. This null-stream can be used to distinguish between actual GW triggers and spurious noise transients in a search for GW bursts using a network of detectors. The biggest source of error in the null

S. Antoci, D. -E. Liebscher, L. Mihich

After recalling the mathematical structure of Einstein&#39;s Hermitian extension of the gravitational theory of 1915, the problem, whether its field equations should admit of phenomenological sources at their right-hand sides, and how this addition should be done, is expounded by relying on a thread of essential insights and achievements by Schrödinger, Kurs

K. A. Bronnikov, S. A. Kononogov

We briefly review the recent experimental results on possible variations of the fine structure constant $α$ on the cosmological time scale and its position dependence. We outline the theoretical grounds for the assumption that $α$ might be variable, mention some phenomenological models incorporating a variable $α$ into the context of modern cosmology and dis

Marian Ioan Munteanu

Warped product CR-submanifolds in Kaehlerian manifolds were intensively studied only since 2001 after the impulse given by B.Y. Chen. Immediately after, another line of research, similar to that concerning Sasakian geometry as the odd dimensional version of Kaehlerian geometry, was developed, namely warped product contact CR-submanifolds in Sasakian manifold

Marek Szydlowski, Jacek Golbiak

The main aim of this paper is to extend the early approach to quantum cosmogenesis provided by Fomin. His approach was developed independently to the well-known Tryon description of the creation of the closed universe as a process of quantum fluctuation of vacuum. We apply the Fomin concept to derive the cosmological observables. We argue that Fomin&#39;s id

Evgeny Korotyaev, Igor Lobanov

We consider the Schrödinger operator on zigzag graphs with a periodic potential. The spectrum of this operator consists of an absolutely continuous part (intervals separated by gaps) plus an infinite number of eigenvalues with infinite multiplicity. We describe all compactly supported eigenfunctions with the same eigenvalue. We define a Lyapunov function, wh

Vincenzo Cavasinni, Dario Grasso, Luca Maccione

The recent detection of $γ$-rays with energy up to 10 TeV from dense regions surrounding some Supernova Remnants (SNR) provides strong, though still not conclusive, evidence that the nucleonic component of galactic Cosmic Rays is accelerated in the supernova outflows. Neutrino telescopes could further support the validity of such scenario by detecting neutri

UKQCD Collaboration, G. Herdoiza, C. McNeile, C. Michael

We review some decays that require knowledge of the decay constants of $0^{+}$ heavy-light mesons. We compute the decay constants of P-wave heavy-light mesons from unquenched lattice QCD, with two degenerate flavours of sea quarks, at a single lattice spacing. The lightest sea quark mass used in the calculation is a third of the strange quark mass. For the c

P. A. Bhobe, K. R. Priolkar, P. R. Sarode

The local atomic structure of Ni-Mn-Ga alloys was explored using Mn and Ga K-edge extended X-ray fine structure (EXAFS) measurement. The changes occuring in the L1$_0$ sub-cell of the martensitic unit cell and the bond lengths obtained from the analysis enables us to propose a scheme for the structural distortions responsible for the modulations and shufflin

Chong-Xing Yue, Li Zhou, Shuo Yang

We investigate the corrections of the littlest Higgs(LH) model and the SU(3) simple group model to single top production at the CERN Large Hardon Collider(LHC). We find that the new gauge bosons $W_{H}^{\pm}$ predicted by the LH model can generate significant contributions to single top production via the s-channel process. The correction terms for the tree-

I. B. Khriplovich, N. Produit

If primordial black holes (PBH) saturate the present upper limit on the dark matter density in our Solar system and if their radiation spectrum is discrete, the sensitivity of modern detectors is close to that necessary for detecting this radiation. This conclusion is not in conflict with the upper limits on the PBH evaporation rate.

A. Beilinson, V. Vologodsky

We give a concise exposition of Voevodsky&#39;s theory of motives.

D. Maslov, G. W. Dueck, D. M. Miller, C. Negrevergne

Quantum circuits are time dependent diagrams describing the process of quantum computation. Usually, a quantum algorithm must be mapped into a quantum circuit. Optimal synthesis of quantum circuits is intractable and heuristic methods must be employed. With the use of heuristics, the optimality of circuits is no longer guaranteed. In this paper, we consider

G. Giorgadze, R. Tevzadze

We discuss possible applications of the 1-D direct and inverse scattering problem to design of universal quantum gates for quantum computation. The potentials generating some universal gates are described.

G. Giorgadze, Z. Melikishvili

In the paper, analysis of a quantum optical system--three-level atom in a quantum electromagnetic field is given. Evolution operators are constructed in closed form.

Maria Bondani, Alessia Allevi, Eleonora Gevinti, Andrea Agliati

An analytical calculation of the interaction geometry of two interlinked second-order nonlinear processes fulfilling phase-matching conditions is presented. The method is developed for type-I uniaxial crystals and gives the positions on a screen beyond the crystal of the entangled triplets generated by the interactions. The analytical results are compared to

W. H. Z. Cardenas, L. F. Canto, M. S. Hussein

We describe a schematic coupled channels transfer calculation for the reaction 6He + 238U at near-barrier energies. We also present a simple semiclassical DWBA calculation of the two neutron transfer. Both calculations are meant to supply the conditions under which the transfer cross section becomes much larger than the complete fusion one at sub-barrier ene

Prasanta K. Panigrahi, P. Manimaran, Ananth Lakhmi, Ram R. Yadav

We have studied periodicities and correlation properties of tree ring width chronology of deodar tree from Joshimath (1584 - 1999 years) and Uttarkashi (1500 - 2002 years) in the western Himalayas and the pre-monsoon (March-April-May) temperature anomalies (1876 - 2003) relative to 1961 -1990 mean, through wavelet analysis. Periodic behavior is observed in t

Horia Decebal Cornean, Pierre Duclos, Benjamin Ricaud

We consider three one dimensional quantum, charged and spinless particles interacting through delta potentials. We derive sufficient conditions which guarantee the existence of at least one bound state.

M. de Montigny, J. Niederle, A. G. Nikitin

All indecomposable finite-dimensional representations of the homogeneous Galilei group which when restricted to the rotation subgroup are decomposed to spin 0, 1/2 and 1 representations are constructed and classified. These representations are also obtained via contractions of the corresponding representations of the Lorentz group. Finally the obtained repre

A. Boettcher, H. Widom

At present there exist numerous different approaches to results on Toeplitz determinants of the type of Szegö&#39;s strong limit theorem. The intention of this paper is to show that Jacobi&#39;s theorem on the minors of the inverse matrix remains one of the most comfortable tools for tackling the matter. We repeat a known proof of the Borodin-Okounkov formul

Evgeny Korotyaev, Igor Lobanov

We consider the magnetic Schrödinger operator on the so-called zigzag periodic metric graph (a quasi 1D continuous model of zigzag nanotubes) with a periodic potential. The magnetic field (with the amplitude $B\in R$) is uniform and it is parallel to the axis of the nanotube. The spectrum of this operator consists of an absolutely continuous part (spectral b

Bozhidar Z. Iliev, Maido Rahula

The paper is devoted to vector fields on the spaces R^2 and R^3, their flow and invariants. Attention is plaid on the tensor representations of the group GL(2,R) and on fundamental vector fields. The rotation group on R^3 is generalized to rotation groups with arbitrary quadrics as orbits.

Steffen Hein

This paper presents the Dual Scattering Channel numerical solution of the Navier-Stokes Equations for quasi-incompressible flow in the Oberbeck-Boussinesq approximation. The implementation in hexahedral non-orthogonal mesh is outlined. A numerical example illustrates the approach.

Dennis Gaitsgory

Let $X$ be a smooth projective curve over a finite field $F_q$. Let $ρ$ be a continuous representation $π(X)\to GL_n(F)$, where $F=F_l((t))$ with $F_l$ being another finite field of order prime to $q$. Assume that $ρ|_{π(\bar{X})}$ is irreducible. De Jong&#39;s conjecture says that in this case $ρ(π(\bar{X}))$ is finite. As was shown in the original paper of

G. Sardanashvily

Given a generic Lagrangian system of even and odd fields, we show that any infinitesimal transformation of its classical Lagrangian yields the identities which Euclidean Green functions of quantum fields satisfy.

Rachid Ahl Laamara, Lalla Btissam Drissi, El Hassan Saidi

Motivated by similarities between quantum Hall systems à la Susskind and aspects of topological string theory on conifold as well as results obtained in hep-th/0601020, we study the dynamics of D-string fluids running in deformed conifold in presence of a strong and constant RR background B-field. We first introduce the basis of D-string system in fluid appr

T. M. Aliev, M. Savci

The transition form factors of the semileptonic decay B_s into scalar D_{s_0}(2317) meson is calculated in the framework of 3-point QCD sum rule. The branching ratio is found to be ~10^(-3) for the (B_s -> D_{s_0}(2317) l nu_l) (l=e,mu) decay, and 10^(-4) for the (B_s -> D_{s_0}(2317) tau nu_tau) decay, respectively.

Michael Maziashvili

Exact conditions on the clock parameters corresponding to the minimal uncertainty in distance measurement are derived in uniform manner for any number of space time dimensions. The result espouses the holography principle no matter what the number of space time dimensions is. In this context the ADD braneworld model is considered. Some remarks are made on de

Alex. E. Shalyt-Margolin

The subject of this study is Quantum and Statistical Mechanics of the Early Universe. In it a new approach to investigation of these two theories - density matrix deformation - is proposed. The distinguishing feature of the proposed approach as compared to the previous ones is the fact that here the density matrix is subjected to deformation, rather than com

Lorenzo Iorio, Giuseppe Giudice

In this paper we investigate the effects that an anomalous acceleration as that experienced by the Pioneer spacecraft after they passed the 20 AU threshold would induce on the orbital motions of the Solar System planets placed at heliocentric distances of 20 AU or larger as Uranus, Neptune and Pluto. It turns out that such an acceleration, with a magnitude o

Fabrice Rossi, Brieuc Conan-Guez

Many real world data are sampled functions. As shown by Functional Data Analysis (FDA) methods, spectra, time series, images, gesture recognition data, etc. can be processed more efficiently if their functional nature is taken into account during the data analysis process. This is done by extending standard data analysis methods so that they can apply to fun

M. Daghofer, D. R. Neuber, A. M. Oles, W. von der Linden

We study a two-dimensional effective orbital superexchange model derived for strongly correlated e_g electrons coupled to t_{2g} core spins in layered manganites. One finds that the ferromagnetic and antiferromagnetic correlations closely compete, and small changes of parameters can switch the type of magnetic order. For the same reason, spin order is easily

M. Daghofer, A. M. Oles, D. R. Neuber, W. von der Linden

We investigate the interplay between spin and orbital correlations in monolayer and bilayer manganites using an effective spin-orbital t-J model which treats explicitly the e_g orbital degrees of freedom coupled to classical t_{2g} spins. Using finite clusters with periodic boundary conditions, the orbital many-body problem is solved by exact diagonalization

Z. Z. Sun, X. R. Wang

Based on the Landau-Lifshitz-Gilbert equation, it can be shown that a circularly-polarized microwave can reverse the magnetization of a Stoner particle through synchronization. In comparison with magnetization reversal induced by a static magnetic field, it can be shown that when a proper microwave frequency is used the minimal switching field is much smalle

Yan Zhao, Pavel Belov, Yang Hao

The finite-difference time-domain (FDTD) method is applied for modelling of wire media as artificial dielectrics. Both frequency dispersion and spatial dispersion effects in wire media are taken into account using the auxiliary differential equation (ADE) method. According to the authors&#39; knowledge, this is the first time when the spatial dispersion effe

Santanu K. Maiti, J. Chowdhury, S. N. Karmakar

We present a detailed study of persistent current and low-field magnetic susceptibility in single isolated normal metal mesoscopic rings and cylinders in the tight-binding model with higher order hopping integral in the Hamiltonian. Our exact calculations show that order of magnitude enhancement of persistent current takes place even in presence of disorder

T. -L. Horng, S. -C. Gou, T. -C. Lin

Based on a velocity formula derived by matched asymptotic expansion, we investigate the dynamics of a circular vortex ring in an axisymmetric Bose-Einstein condensate in the Thomas-Fermi limit. The trajectory for an axisymmetrically placed and oriented vortex ring is entirely determined, revealing that the vortex ring generally precesses in condensate. The l

M. Stopa, C. M. Marcus

We employ density functional calculated eigenstates as a basis for exact diagonalization studies of semiconductor double quantum dots, with two electrons, through the transition from the symmetric bias regime to the regime where both electrons occupy the same dot. We calculate the singlet-triplet splitting $J(ε)$ as a function of bias detuning $ε$ and explai

John A. Marsh, Miguel A. Fuentes, Luis G. Moyano, Constantino Tsallis

We consider probabilistic models of N identical distinguishable, binary random variables. If these variables are strictly or asymptotically independent, then, for N>>1, (i) the attractor in distribution space is, according to the standard central limit theorem, a Gaussian, and (ii) the Boltzmann-Gibbs-Shannon entropy is extensive, meaning that S_BGS(N) ~ N .

Christian D. Santangelo, Randall D. Kamien

We develop an explicit and tractable representation of a twist-grain-boundary phase of a smectic A liquid crystal. This allows us to calculate the interaction energy between grain boundaries and the relative contributions from the bending and compression deformations. We discuss the special stability of the 90 degree grain boundaries and discuss the relation

M. Pustilnik, L. Borda

We consider low temperature transport through a lateral quantum dot asymmetrically coupled to two conducting leads, and tuned to the mixed-valence region separating two adjacent Coulomb blockade valleys with spin S=1/2 and S=1 on the dot. We demonstrate that this system exhibits a quantum phase transition driven by the gate voltage. In the vicinity of the tr

Daniel A. Dale, the SINGS Team

The Spitzer Space Telescope is pushing into new frontiers in high redshift astronomy. Closer to home, Spitzer is making an equally large impact on our understanding of galaxy formation and evolution. In this contribution we present mid-infrared diagnostics based largely on data from the Spitzer Infrared Nearby Galaxies Survey (SINGS). Our main result is that

D. A. Dale, J. D. T. Smith, L. Armus, B. A. Buckalew

Mid-infrared diagnostics are presented for a large portion of the Spitzer Infrared Nearby Galaxies Survey (SINGS) sample plus archival data from the Infrared Space Observatory and the Spitzer Space Telescope. Our main result is that these mid-infrared diagnostics effectively constrain a target&#39;s dominant power source. The combination of a high ionization

Suzan Edwards, William Fischer, Lynne Hillenbrand, John Kwan

In a high dispersion 1 micron survey of 39 classical T Tauri stars veiling is detected in 80%, and He I 10830 and Pgamma line emission in 97% of the stars. On average, the 1 micron veiling exceeds the level expected from previously identified sources of excess emission, suggesting the presence of an additional contributor to accretion luminosity in the star-

Klaus W. Hodapp, Andreas Seifahrt, Gerard A. Luppino, Richard Wainscoat

The University of Hawaii Wide-Field Imager (UHWFI) is a focal compressor system designed to project the full half-degree field of the UH 2.2 m telescope onto the refurbished UH 8Kx8K CCD camera. The optics use Ohara glasses and are mounted in an oil-filled cell to minimize light losses and ghost images from the large number of internal lens surfaces. The UHW

Nicole F. Bell, Elena Pierpaoli, Kris Sigurdson

We investigate signatures of neutrino scattering in the Cosmic Microwave Background (CMB) and matter power spectra, and the extent to which present cosmological data can distinguish between a free streaming or tightly coupled fluid of neutrinos. If neutrinos have strong non-standard interactions, for example, through the coupling of neutrinos to a light boso