August 2002 arXiv papers — page 13

Peter Ostermann

Since 1983 the meter is defined to be the "length of the path travelled by light in vacuum during a time interval of 1/299792458 of a second". If there was exactly one single consistent method of synchronizing clocks, or if all corresponding methods were equivalent, one could infer from the validity of special relativity theory on a definite value of

G. Sardanashvily

The classical theory of gravity is formulated as a gauge theory on a frame bundle with spontaneous symmetry breaking caused by the existence of Dirac fermionic fields. The pseudo-Riemannian metric (tetrad field) is the corresponding Higgs field. We consider two variants of this theory. In the first variant, gravity is represented by the pseudo-Riemannian met

Joseph Y. Halpern, Ron van der Meyden

SPKI/SDSI is a proposed public key infrastructure standard that incorporates the SDSI public key infrastructure. SDSI's key innovation was the use of local names. We previously introduced a Logic of Local Name Containment that has a clear semantics and was shown to completely characterize SDSI name resolution. Here we show how our earlier approach can be

Robert C. Steinke, Gary J. Nutt

Memory consistency models have been developed to specify what values may be returned by a read given that, in a distributed system, memory operations may only be partially ordered. Before this work, consistency models were defined independently. Each model followed a set of rules which was separate from the rules of every other model. In our work we have def

Luca Capriotti, Federico Becca, Alberto Parola, Sandro Sorella

Twenty-five years after the first proposal, the question whether the ground state of a frustrated spin-half system is well described by a spin-liquid Resonating Valence Bond (RVB) wave function is still controversial. A physically transparent representation of a RVB state can be obtained in fermionic representation with a standard BCS-type pairing wave funct

Mogus Mochena, P. J. Lin-Chung

We have computed the local magnetic moments of manganese and neighboring arsenic for various cluster configurations on the (001) surface of GaAs bulk crystal using a cluster of 512 atoms. We obtained for manganese a substantial local magnetic moment of 3.66 Bohr magnetons for all cases considered. The induced magnetic moment of arsenic is less than that of m

Luca Capriotti, Federico Becca, Sandro Sorella, Alberto Parola

A comment to the paper by S. Chen, H. Büttner, and J. Voit, [Phys. Rev. Lett. {\bf 87}, 087205 (2001)].

M. W. C. Dharma-wardana, Marek Z. Zgierski

Electroluminescence in organic light emitting diode (OLED) materials occurs via the recombination of excitonic electrons-hole pairs Only the singlet excitons of commonly used OLED materials, e.g., Aluminum trihydroxyquinoline (AlQ$_3$), decay radiatively, limiting the external quantum efficiency to a maximum 25%. Thus 75% of the energy is lost due to the tri

Klaus Voelker, Manfred Sigrist

A multiband superconductor with a conventional phonon mechanism can develop an unconventional state with a nontrivial order parameter phase relation between the individual bands. We propose that such a state can explain recent experimental results on MgCNi3, which are suggestive of both s-wave pairing symmetry and of unconventional superconductivity. We show

Paolo M. Pumilia

An algorithm to simulate the dynamics of a quantum state over a three-site lattice interacting with classical harmonic oscillators has been devised. The oscillators are linearly coupled to the quantum state and are acted upon by a fluctuation-dissipation process to take the equilibrium thermal environment into account, thus allowing to investigate how stocha

Nacir Tit, M. W. C. Dharma-wardana

The electronic structures of zig-zag and arm-chair single-walled carbon nanotubes interacting with a transitional-metal atomic nanowire of Ni have been determined. The Ni nanowire creates a large electron density of states (DOS)at the Fermi energy. The dependence of the enhanced DOS on the spin state and positioning of the transition-metal wire(inside or out

A. Waelte, H. Rosner, M. D. Johannes, G. Fuchs

Polycrystalline samples of the recently discovered MgCNi3 superconductor were investigated by transport, ac susceptibility, dc magnetization and specific heat measurements in magnetic fields up to 16 T. Consistent results were obtained for the temperature dependence of the upper critical field H_c2(T) from resistance, ac susceptibility and specific heat meas

V. G. Kogan, V. L. Pokrovsky

We argue that in channels cut out of anisotropic single crystal superconductors and narrow on the scale of London penetration depth, the persistent current must cause the transverse phase difference provided the current does not point in any of the principal crystal directions. The difference is proportional to the current value and depends on the anisotropy

K. P. Schmidt, C. Knetter, G. S. Uhrig

We present a novel extrapolation scheme for high order series expansions. The idea is to express the series, obtained in orders of an external variable, in terms of an internal parameter of the system. Here we apply this method to the 1-triplet dispersion in an antiferromagnetic $S=1/2$ Heisenberg ladder. By the use of the internal parameter the accuracy of

M. Moskalets, M. Buttiker

We develop the Floquet scattering theory for quantum mechanical pumping in mesoscopic conductors. The nonequilibrium distribution function, the dc charge and heat currents are investigated at arbitrary pumping amplitude and frequency. For mesoscopic samples with discrete spectrum we predict a sign reversal of the pumped current when the pump frequency is equ

L. Oberbeck, N. J. Curson, M. Y. Simmons, R. Brenner

The incorporation of phosphorus in silicon is studied by analyzing phosphorus delta-doped layers using a combination of scanning tunneling microscopy, secondary ion mass spectrometry and Hall effect measurements. The samples are prepared by phosphine saturation dosing of a Si(100) surface at room temperature, a critical annealing step to incorporate phosphor

A. Laio, M. Parrinello

We introduce a novel and powerful method for exploring the properties of the multidimensional free energy surfaces of complex many-body systems by means of a coarse-grained non-Markovian dynamics in the space defined by a few collective coordinates.A characteristic feature of this dynamics is the presence of a history-dependent potential term that, in time,

E. A. Pashitskii, S. V. Mashkevich, S. I. Vilchynskyy

A self-consistent model of the superfluid (SF) state of a Bose liquid with strong interaction between bosons is considered, in which at T=0, along with a weak single-particle Bose-Einstein condensate (BEC), there exists an intensive pair coherent condensate (PCC) of bosons, analogous to the Cooper pair condensate of fermions. Such a PCC emerges due to an eff

X. L. Wang, S. H. Zhou, M. J. Qin, P. R. Munroe

Polycrystalline MgB2 samples with 10 wt % silicon powder addition were prepared by an in-situ reaction process. Two different Si powders, one with coarse (44 mm) and the other with nano-size (<100 nm) particles were used for making samples. The phases, microstructures, and flux pinning were characterized by XRD, TEM, and magnetic measurements. It was observe

Reginald D. Smith

The topology of an instant messaging system is described. Statistical measures of the network are given and compared with the statistics of a comparable random graph. The scale-free character of the network is examined and implications are given for the structure of social networks and instant messenger security.

I. H. Stairs, S. E. Thorsett, J. H. Taylor, A. Wolszczan

We have continued our long term study of the double-neutron-star binary pulsar PSR B1534+12, using new instrumentation to make very high precision measurements at the Arecibo Observatory. We have significantly improved our solution for the astrometric, spin, and orbital parameters of the system, as well as for the five &#34;post-Keplerian&#34; orbital parame

W. Becker, G. G. Pavlov

CONTENTS The Milky Way -- Pulsars and Isolated Neutron Stars / Introduction: Historical Overview / Physics and Astrophysics of Isolated Neutron Stars / Rotation-powered Pulsars: The Magnetic Braking Model / High-energy Emission Models / Magnetospheric Emission Models / Thermal Evolution of Neutron Stars / Photospheric Emission from Cooling Neutron Stars / Th

H. K. C. Yee, G. Mallen-Ornelas, S. Seager, M. D. Gladders

Searching for transits provides a very promising technique for finding close-in extra-solar planets. Transiting planets present the advantage of allowing one to determine physical properties such as mass and radius unambiguously. The EXPLORE (EXtra-solar PLanet Occultation REsearch) project is a transit search project carried out using wide-field CCD imaging

W. A. Heindl, D. M. Smith

We observed the &#34;micro-quasar&#34; GRS 1758-258 four times with Chandra. Two HRC-I observations were made in 2000 September-October spanning an intermediate-to-hard spectral transition (identified with RXTE). Another HRC-I and an ACIS/HETG observation were made in 2001 March following a hard-to-soft transition to a very low flux state. Based on the three

Ravi K. Sheth, Bhuvnesh Jain

We develop the formalism to include substructure in the halo model of clustering. Real halos are not likely to be perfectly smooth, but have substructure which has so far been neglected in the halo model -- our formalism allows one to estimate the effects of this substructure on measures of clustering. We derive expressions for the two-point correlation func

Massimo Ricotti

A problem still unsolved in cosmology is the identification of the sources of radiation able to reionize HI in the intergalactic medium (IGM) by z~6. Theoretical works and observations seem to indicate that the fraction, f_esc, of HI ionizing radiation emitted from galaxies that escapes into the IGM is small in the local universe (f_esc < 10%). At high redsh

Henk Hoekstra

Weak gravitational lensing provides a direct way to study the mass distribution of clusters of galaxies at large radii. Unfortunately, large scale structure along the line of sight also contributes to the lensing signal, and consequently affects the measurements. We quantify the effect of distant uncorrelated large scale structure on the inferred mass profil

Chris Blake, Jasper Wall

We quantify the angular clustering of radio galaxies in the NVSS and FIRST radio surveys using the two-point correlation function and the moments of counts-in-cells - both important points of comparison with theory. These investigations consistently demonstrate that the slope of the correlation function for radio galaxies agrees with that for optically-selec

S. McBreen, B. McBreen, L. Hanlon, F. Quilligan

The cumulative light curves of gamma-ray bursts (GRBs) smooth the spiky nature of the running light curve. The cumulative count increases in an approximately linear way with time t for most bursts. In 19 out of 398 GRBs with T90 > 2s, the cumulative light curve was found to increase with time as t^2 implying a linear increase in the running light curve. The

S. McBreen, B. McBreen, L. Hanlon, F. Quilligan

The cumulative light curves of a large sample of gamma-ray bursts (GRBs) were obtained by summing the BATSE counts. The smoothed profiles are much simpler than the complex and erratic running light curves that are normally used. For most GRBs the slope of the cumulative light curve (S) is approximately constant over a large fraction of the burst. The bursts

Daniel Schaudel, Werner Becker, Wolfgang Voges, Bernd Aschenbach

Identified radio supernova remnants (SNRs) in the Galaxy comprise an incomplete sample of the SNR population due to various selection effects. ROSAT performed the first all-sky survey with an imaging X-ray telescope, and thus provides another window for finding SNRs and compact objects that may reside within them. Performing a search for extended X-ray sourc

L. Gizon, T. L. Duvall, J. Schou

Supergranulation on the surface of the Sun is an organized cellular flow pattern with a characteristic scale of 30 Mm. It is superficially similar to the well understood granulation that operates at the 1.5 Mm natural scale of convection, which has led to the conventional view that supergranulation has its origin in the convective motion of cells of gas, tho

A. Del Popolo, M. Gambera

We study the effect of the interaction between small scale clumps having velocities larger than the average escape velocity v_{\rm esc} and bound clumps (having v<v_{\rm esc}), on clusters of galaxies evolution. We find that the collapse of the bound clumps is accelerated with respect to the homogeneous case (Gunn & Gott&#39;s model - Gunn & Gott 1972). A co

A. Del Popolo, E. N. Ercan, M. Gambera

In this paper, we study the role of shear fields on the evolution of density perturbations embedded in a Friedmann flat background universe, by studying the evolution of a homogeneous ellipsoid model. In this context, we show that while the effect of the shear is that of increasing the growth rate of the density contrast of a mass element, the angular moment

H. M. Antia

Using even-order frequency splitting coefficients of global p-modes it is possible to infer the magnetic field in the solar interior as a function of radial distance and latitude. Results obtained using GONG and MDI data are discussed. While there is some signal of a possible magnetic field in the convection zone, there is little evidence for any temporal va

Tero T. Heikkilä, Jani Särkkä, Frank K. Wilhelm

Recent experiments have demonstrated the nonequilibrium control of the supercurrent through diffusive phase-coherent normal-metal weak links. The experimental results have been accurately described by the quasiclassical Green&#39;s function technique in the Keldysh formalism. Taking into account the geometry of the structure, different energy scales and the

Dmitri Souptel, Zakir Hossain, Gunter Behr, Wolfgang Loser

Polycrystalline samples of LiBC compounds, which were predicted as possible candidate for high-Tc superconductivity, have been synthesised by a flux method and investigated by means of electrical resistivity and magnetic susceptibility. Scanning electron microscopy and X-ray diffraction patterns showed a plate-like morphology and a single-phase nature of LiB

Nilanjana Datta, Tom Kennedy

For the antiferromagnetic, highly anisotropic XZ and XXZ quantum spin chains, we impose periodic boundary conditions on chains with an odd number of sites to force an interface (or kink) into the chain. We prove that the energy of the interface depends on the momentum of the state. This shows that at zero temperature the interface in such chains is not stabl

E. Arik, O. Cakir, S. A. Cetin, S. Sultansoy

The pseudoscalar quarkonium state, eta_4 1^S_0, formed by the Standard Model (SM) fourth generation quarks, is the best candidate among the fourth generation quarkonia to be produced at the LHC and VLHC. The production of this J^{PC} = 0^{-+} resonance is discussed and the background processes are studied to obtain the integrated luminosity limits for the di

I. Pitowsky

We develop a systematic approach to quantum probability as a theory of rational betting in quantum gambles. In these games of chance the agent is betting in advance on the outcomes of several (finitely many) incompatible measurements. One of the measurements is subsequently chosen and performed and the money placed on the other measurements is returned to th

LiXiang Cen, XinQi Li, YiJing Yan, HouZhi Zheng

The proposal of the optical scheme for holonomic quantum computation is evaluated based on dynamical resolution to the system beyond adiabatic limitation. The time-dependent Schrödinger equation is exactly solved by virtue of the cranking representation and gauge transformation approach. Besides providing rigorous confirmation to holonomies of the geometrica

LiXiang Cen, XinQi Li, YiJing Yan

We clarify that the nonadiabatic scheme based on a parallel extension of the adiabatic scenario cannot realize the desired goal of quantum computation.

M. Hemmo, I. Pitowsky

We argue that a certain type of many minds (and many worlds) interpretations of quantum mechanics due to Lockwood (and Deutsch) do not provide a coherent interpretation of the quantum mechanical probabilistic algorithm. By contrast, in Albert and Loewer&#39;s version of the many minds interpretation there is a coherent interpretation of the quantum mechanica

Steffen Klassert, Daniel Lenz, Peter Stollmann

Despite all the analogies with &#34;usual random&#34; models, tight binding operators for quasicrystals exhibit a feature which clearly distinguishes them from the former: the integrated density of states may be discontinuous. This phenomenon is identified as a local effect, due to occurrence of eigenfunctions with bounded support.

Daniel Lenz

We show that aperiodic linearly repetitive Delone sets are densely repetitive. This confirms a conjecture of Lagarias and Pleasants.

Leo Liberti

Certain types of bilinearly defined sets in $\mathbb{R}^n$ exhibit a higher degree of linearity than what is apparent by inspection.

V. NguyenKhac, K. NguyenVan

We give a geometric characterization of extremal sets in ell_p spaces that generalizes our previous result for such sets in Hilbert spaces.

V. NguyenKhac, K. NguyenVan

We give a characterization of extremal sets in Hilbert spaces that generalizes a classical theorem of H. W. E. Jung. We investigate also the behaviour of points near to the circumsphere of such a set with respect to the Kuratowski and Hausdorff measures of non-compactness.

Alon E. Faraggi

The Standard Model data suggests the realization of grand unification structures in nature, in particular that of SO(10). A class of string vacua that preserve the SO(10) embedding, are the three generation free fermion heterotic-string models, that are related to Z2xZ2 orbifold compactification. Attempts to use the M-theory framework to explore further this

Zhou Hong, Ma Wen-Gan, Zhang Ren-You

The precise calculations are carried out on the flavor changing neutral current couplings in the process $pp \to gg \to t\bar{c}(\bar{t}c)$ at the large hadron collider(LHC) and very large hadron collider(VLHC) in both frameworks of the minimal standard model(MSM) and its extension with extra dimensions. We find that the effects from the large extra dimensio

Marko B. Popovic

I discuss standard motivation for the new physics at the 1 TeV scale. Although the arguments for new exotic phenomena seem to be very supportive I argue that the Standard Model still might offer a good description far beyond this energy scale. I analyze three Standard Model cases with specific boundary conditions at the lowest energies. These conditions esse

J. J. Reidy, L. N. Bolen, L. M. Cremaldi, T. J. Ray

One often wishes to quickly add a few overlined characters such as anti-B0 or anti-neutrino to a Microsoft Word document. Underlined characters are straightforward but overlined characters require equation editor which makes small picture files. The font here allows one to directly add overlined English and the most used overlined Greek characters to Microso

A. L. Barbosa, L. C. T. Guillen, J. G. Pereira

Based on the equivalence between a gauge theory for the translation group and general relativity, a teleparallel version of the non-abelian Kaluza-Klein theory is constructed. In this theory, only the fiber-space turns out to be higher-dimensional, spacetime being kept always four-dimensional. The resulting model is a gauge theory that unifies, in the Kaluza

Yanbei Chen

According to quantum measurement theory, &#34;speed meters&#34; -- devices that measure the momentum, or speed, of free test masses -- are immune to the standard quantum limit (SQL). It is shown that a Sagnac-interferometer gravitational-wave detector is a speed meter and therefore in principle it can beat the SQL by large amounts over a wide band of frequen

Alessandra Buonanno, Yanbei Chen

By mapping the signal-recycling (SR) optical configuration to a three-mirror cavity, and then to a single detuned cavity, we express SR optomechanical dynamics, input--output relation and noise spectral density in terms of only three characteristic parameters: the (free) optical resonant frequency and decay time of the entire interferometer, and the laser po

Charles Sauerbier

The mathematical basis motivating the &#34;implication operator&#34; of the polySAT algorithm and its function is examined. Such is not undertaken with onerous rigor of symbolic mathematics; a more intuitive visual appeal being employed to present some of the mathematical premises underlying function of the implication operator.

W. -X. Zhou, D. Sornette, V. Pisarenko

We extend the analysis of [Zhou and Sornette, Physica D 165, 94-125, 2002] showing statistically significant log-periodic corrections to scaling in the moments of the energy dissipation rate in experiments at high Reynolds number ($\approx 2500$) of three-dimensional fully developed turbulence. First, we develop a simple variant of the canonical averaging me

Haye Hinrichsen

We introduce an efficient cellular automaton for the coagulation-fission process with diffusion 2A->3A, 2A->A in arbitrary dimensions. As the well-known Domany-Kinzel model, it is defined on a tilted hypercubic lattice and evolves by parallel updates. The model exhibits a non-equilibrium phase transition from an active into an absorbing phase and its critica

Margarita Valdez-Gutierrez, Margarita Rosado, Ivanio Puerari, Leonid Georgiev

A detailed kinematic analysis of ionized gas in the nearby irregular galaxy NGC 4449 is presented. Observations are conducted in the spectral lines of Halpha and [SII]. Our scanning Fabry--Perot interferometric observations are presented from both a global as well as a local perspective. We have analysed the global velocity field, the spatially extended diff

Anandmayee Tej, Kailash C. Sahu, T. Chandrasekhar, N. M. Ashok

We present a statistical method to derive the mass functions of open clusters using sky survey data such as the 2 Micron All Sky Survey and the Guide Star Catalogue. We have used this method to derive the mass functions in the stellar/substellar regime of three young, nearby open clusters, namely IC 348, Sigma-Orionis and Pleiades. The mass function in the l

V. Celebonovic

This is an intorduction to some of the basic methods and results of dense matter physics.It is aimed at readers interested in astrophysical and physical applications.

B. Willems, U. Kolb

Four evolutionary channels leading to the formation of wide binary millisecond pulsars are investigated. The majority of binary millisecond pulsars are found to descend from systems in which the most massive component undergoes a common-envelope phase prior to the supernova explosion leading to the birth of the neutron star. The orbital period distribution o

J. L. Zdunik

The minimum value of the radius of strange star covered by the crust of nuclear matter is determined. The results for the maximum possible thickness of the crust (up to the neutron drip) as well as the possibility of thinner crust postulated by some authors are discussed. The minimum radius of the strange star with maximal crust is 5.5 km. The useful scaling

Zuo-Hong Li, Tao Huang, Jin-Zuo Sun, Zhen-Hong Dai

We make a detailed analysis of the $BBρ(DDρ)$ and $B^*Bρ(D^{*}Dρ)$ strong couplings $g_{BBρ}(g_{DDρ})$ and $g_{B^*Bρ}(g_{D^{*}Dρ})$ using QCD light cone sum rules(LCSR). The existing some negligence is pointed out in the previous LCSR calculation on $g_{B^*Bρ} (g_{D^{\ast}Dρ}$) and an updated estimate is presented. Our findings can be used to understand the

Vladislav Kargin

This paper describes a new method of bond portfolio optimization based on stochastic string models of correlation structure in bond returns. The paper shows how to approximate correlation function of bond returns, compute the optimal portfolio allocation using Wiener-Hopf factorization, and check whether a collection of bonds presents arbitrage opportunities

Yuri Shtanov, Varun Sahni

We study cosmological braneworld models with a single timelike extra dimension. Such models admit the intriguing possibility that a contracting braneworld experiences a natural bounce without ever reaching a singular state. This feature persists in the case of anisotropic braneworlds under some additional and not very restrictive assumptions. Generalizing ou

Oliver DeWolfe, Steven B. Giddings

Warped compactifications with branes provide a new approach to the hierarchy problem and generate a diversity of four-dimensional thresholds. We investigate the relationships between these scales, which fall into two classes. Geometrical scales, such as thresholds for Kaluza-Klein, excited string, and black hole production, are generically determined soley b

E. Silva, R. Marcon, S. Sarti, R. Fastampa

We present measurements of the microwave complex conductivity at 23.9 and 48.2 GHz in YBa$_{2}$Cu$_{3}$O$_{7-δ}$ films, in the fluctuational region above $T_{c}$. With increasing temperature, the fluctuational excess conductivity drops much faster than the well-known calculations within the time-dependent Ginzburg-Landau theory [H. Schmidt {\em Z. Phys.} {\b

L. -A. Wu, D. A. Lidar

We show how to construct a universal set of quantum logic gates using control over exchange interactions and single- and two-spin measurements only. Single-spin unitary operations are teleported instead of being executed directly, thus eliminating a major difficulty in the construction of several of the most promising proposals for solid-state quantum comput

T. C. Ralph, E. H. Huntington

We investigate the conditions under which unconditional dense coding can be achieved using continuous variable entanglement. We consider the effect of entanglement impurity and detector efficiency and discuss experimental verification. We conclude that the requirements for a strong demonstration are not as stringent as previously thought and are within the r

Bo Gao

We discuss the concept and design of effective atom-atom potentials that accurately describe any physical processes involving only states around the threshold. The existence of such potentials gives hope to a quantitative, and systematic, understanding of quantum few-atom and quantum many-atom systems at relatively low temperatures.

R. M. Jones, R. H. Miller, J. W Wang

The progress of a multiple bunches of electrons through several thousand accelerator structures results in a wakefield which if left unchecked will kick successive bunches off the axis of the accelerator and can at the very least dilute the final luminosity of the final colliding beams, or at worst can lead to a BBU (Beam Break Up) instability. In order to d

Jian-Miin Liu

The generalized Finsler geometry, as well as Finsler geometry, is a generalization of Riemann geometry. The generalized Finsler geometry can be endowed with the Cartan connection. The generalized Finsler geometry and its Cartan connection are, as the necessary mathematical tools, involved in our modification of special relativity, which is made by assuming t

R. R. Gadyl&#39;shin

We obtain necessary and sufficient conditions for emerging of small eigenvalue for Schrödinger operator on plane under local operator perturbations. In the case the eigenvalue emerges we construct its asymptotics. The examples are given.

Zuo-Hong Li, Xiang-Yao Wu, Tao Huang

The radiative decay $ B_{q}^*\to B_{q}γ(q=u,d, or s) $ is reexamined with a modified light-cone QCD sum rule method, in which adequate chiral operators are chosen as the interpolating fields in the correlators used for a sum rule estimate of the relevant coupling $ g_{B_{q}^*B_{q}γ} $. The resulting sum rules not only show the physical picture consistent wit

FOCUS Collaboration

Using the FOCUS spectrometer with photon beam energies between 20 and 160 \gev, we confirm the existence of a diffractively photoproduced enhancement in $K^+K^-$ at 1750 \mevcc with nearly 100 times the statistics of previous experiments. Assuming this enhancement to be a single resonance with a Breit-Wigner mass shape, we determine its mass to be $1753.5\pm

K. K. Nandi, Yuan-Zhong Zhang

Using a novel approach, we work out the general relativistic effects on the quantum interference of de Broglie waves associated with thermal neutrons. The unified general formula is consistent with special relativistic results in the flat space limit. It is also shown that the exact geodesic equation contains in a natural way a gravitational analog of the Ah

Patricia Purdue, Yanbei Chen

In the quest to develop viable designs for third-generation optical interferometric gravitational-wave detectors (e.g., LIGO-III and EURO), one strategy is to monitor the relative momentum or speed of the test-mass mirrors, rather than monitoring their relative position. A previous paper analyzed a straightforward but impractical design for a {\it speed-mete

Sumiyoshi Abe, Norikazu Suzuki

The statistical properties of the seismic time series data in southern California are studies. In particular, the calm time intervals, which are the time intervals between successive significant earthquakes above the fixed threshold value of magnitude, are analyzed. It is found that the system undergoes a series of transition between stationary states, whose

E. Silva, R. Marcon, R. Fastampa, M. Giura

We present measurements of the fluctuational excess conductivity at 48 GHz and 24 GHz in YBa$_{2}$Cu$_{3}$O$_{7-δ}$ films above the transition temperature. The measurements depart from the gaussian prediction for finite-frequency fluctuational conductivity. We focus on the region not too close to $T_{c}$, where the real part of the excess conductivity drops

Subir Sachdev

This is a `News and Views&#39; article discussing recent proposals for ground states of many boson systems which are neither superfluids nor Mott insulators.

Stanley L. Robertson, Darryl J. Leiter

In previous work we found that many of the spectral properties of x-ray binaries, including both galactic black hole candiates (GBHC) and neutron stars, were consistent with the existence of intrinsically magnetized central objects. Here we review and extend the observational evidence for the existence of intrinsically magnetized GBHC and show that their exi

D. Blaschke, H. Grigorian, G. Poghosyan

For the classification of rotating compact stars with two high density phases a phase diagram in the angular velocity (Omega) - baryon number (N) plane is investigated. The dividing line N_crit(Omega) between configurations with one and two phases is correlated to a local maximum of the moment of inertia and can thus be subject to experimental verification b

Cassio Barbosa, Augusto Damineli, Robert Blum, Peter Conti

We present the results of high-resolution mid-infrared observations of the source NGC 3576 IRS 1. Near diffraction-limited images were taken at the Gemini South Observatory through OSCIR&#39;s filters N, 7.9, 9.8, 12.5 and IHW18. The source IRS 1 was resolved into 3 sources for the first time at mid-infrared wavelengths. For each source we constructed the SE

G. L. Granato, L. Silva, G. De Zotti, L. Danese

In view of the extensive evidence of tight inter-relationships between spheroidal galaxies (and galactic bulges) with massive black holes hosted at their centers, a consistent model must deal jointly with the evolution of the two components. We describe one such model, which successfully accounts for the local luminosity function of spheroidal galaxies, for

L. Silva, G. L. Granato, A. Bressan, P. Panuzzo

Our multi-wavelength model GRASIL for the SED of galaxies is described, in particular the recent extension to the radio and X-ray range. With our model we can study different aspects of galaxy evolution by exploiting all available spectral observations, where different emission components dominate.

A. T. Tokunaga, C. Ftaclas, J. R. Kuhn, P. Baudoz

General arguments for optimized coronagraphy in the search for planets are presented. First, off-axis telescopes provide the best telescopic platforms for use with coronagraphy, and telescope fabrication technology now allows the fabrication of such telescopes with diameters of up to 6.5 m. We show that in certain circumstances a smaller telescope with an of

Hector Aceves, Hector Velazquez

A series of N-body simulations aimed to study the dynamics of small groups of galaxies are presented. The properties of small galaxy groups are very well reproduced, and those of Hickson&#39;s compact groups are well reproduced by the most advanced stage of collapsing groups. We find no overmerging problem in our simulations. An important fraction of groups

R. O. de Mello, V. O. Rivelles

We prove that the extended Poincare group in (1+1) dimensions is non-nilpotent solvable exponential, and therefore that it belongs to type I. We determine its first and second cohomology groups in order to work out a classification of the two-dimensional relativistic elementary systems. Moreover, all irreducible unitary representations of the extended Poinca

K. V. Samokhin

We study the order parameter symmetry in a hexagonal crystal with co-existing superconductivity and ferromagnetism. An experimental example is provided by carbon-based materials, such as graphite-sulfur composites, in which an evidence of such co-existence has been recently discovered. The presence of a non-zero magnetization in the normal phase brings about

Caslav Brukner, Myungshik S. Kim, Jian-Wei Pan, Anton Zeilinger

We establish a mapping between a continuous variable (CV) quantum system and a discrete quantum system of arbitrary dimension. This opens up the general possibility to perform any quantum information task with a CV system as if it were a discrete system of arbitrary dimension. The Einstein-Podolsky-Rosen state is mapped onto the maximally entangled state in

Sylvain Capponi, Didier Poilblanc

Using 4-site plaquette or rung basis decomposition, the CORE method is applied to 2-leg and 4-leg t-J ladders and cylinders. Resulting range-2 effective hamiltonians are studied numerically on periodic rings taking full advantage of the translation symmetry as well as the drastic reduction of the Hilbert space. We investigate the role of magnetic and fermion

Ionel Tifrea, Michael E. Flatte

We present formulas for the nuclear and electronic spin relaxation times due to the hyperfine interaction for nanostructed systems and show that the times depend on the square of the local density of electronic states at the nuclear position. A drastic sensitivity (orders of magnitude) of the electronic and nuclear spin coherence times to small electric fiel

L. H. Ford, Adam D. Helfer, Thomas A. Roman

We construct a particular class of quantum states for a massless, minimally coupled free scalar field which are of the form of a superposition of the vacuum and multi-mode two-particle states. These states can exhibit local negative energy densities. Furthermore, they can produce an arbitrarily large amount of negative energy in a given region of space at a

Hisakazu Minakata, Hiroshi Nunokawa, Stephen Parke

The measurement of the mixing angle θ_{13}, sign of Δm^2_{13} and the CP or T violating phase δis fraught with ambiguities in neutrino oscillation. In this paper we give an analytic treatment of the paramater degeneracies associated with measuring the ν_μ-> ν_e probability and its CP and/or T conjugates. For CP violation, we give explicit solutions to allow

Yuri V. Lvov, Esteban G. Tabak

A novel canonical Hamiltonian formalism is developed for long internal waves in a rotating environment. This includes the effects of background vorticity and shear on the waves. By restricting consideration to flows in hydrostatic balance, superimposed on a horizontally uniform background of vertical shear and vorticity, a particularly simple Hamiltonian str

F. J. Burnell, R. B. Mann, T. Ohta

We consider the 3-body problem in relativistic lineal gravity and obtain an exact expression for its Hamiltonian and equations of motion. While general-relativistic effects yield more tightly-bound orbits of higher frequency compared to their non-relativistic counterparts, as energy increases we find in the equal-mass case no evidence for either global chaos

Qaisar Shafi, Zurab Tavartkiladze

Working with a ${\cal U}(1)$ flavor symmetry, we show how the hierarchical structure in the charged fermion sector and a democratic approach for neutrinos that yields large solar and atmospheric neutrino mixings can be simultaneously realized in the MSSM framework. However, in SU(5) due to the unified multiplets we encounter difficulties. Namely, democracy f

A. Mora, A. Natta, C. Eiroa, C. A. Grady

We present the results of a high spectral resolution study of the circumstellar (CS) gas around the intermediate mass, pre-main sequence star UX Ori. The results are based on a set of 10 echelle spectra, monitoring the star on time scales of months, days and hours. A large number of transient blueshifted and redshifted absorption features are detected in the

J. G. Russo, A. A. Tseytlin

We find a general class of pp-wave string solutions with NS-NS $H_3$ or R-R $F_3$ field strengths, which are analogous to solutions with non-constant $F_5$ recently considered by Maldacena and Maoz (hep-th/0207284). We show that: (i) all pp-wave solutions supported by non-constant $H_3$ or $F_p$ fields are exact type II superstring solutions to all orders in