August 2008 arXiv papers — page 10
Showing 901–1,000 of 4,272 papers
K. Dolag, S. Borgani, G. Murante, V. Springel
The abundance and structure of dark matter subhalos has been analyzed extensively in recent studies of dark matter-only simulations, but comparatively little is known about the impact of baryonic physics on halo substructures. We here extend the SUBFIND algorithm for substructure identification such that it can be reliably applied to dissipative hydrodynamic
F. Mahmoudi
We describe SuperIso v3.0 which is a public program for evaluation of flavor physics observables in the Standard Model (SM), general two-Higgs-doublet model (2HDM), minimal supersymmetric Standard Model (MSSM) and next to minimal supersymmetric Standard Model (NMSSM). SuperIso v3.0, in addition to the branching ratio of B -> X_s gamma and the isospin asymmet
C. Aubin, J. Laiho, S. Li, M. F. Lin
We calculate results for K to pi and K to 0 matrix elements to next-to-leading order in 2+1 flavor partially quenched chiral perturbation theory. Results are presented for both the Delta I=1/2 and 3/2 channels, for chiral operators corresponding to current-current, gluonic penguin, and electroweak penguin 4-quark operators. These formulas are useful for stud
M. Rempel, M. Schuessler, M. Knoelker
Results of a 3D MHD simulation of a sunspot with a photospheric size of about 20 Mm are presented. The simulation has been carried out with the MURaM code, which includes a realistic equation of state with partial ionization and radiative transfer along many ray directions. The largely relaxed state of the sunspot shows a division in a central dark umbral re
A. Just, P. Berczik, M. I. Petrov, A. Ernst
Tidal tails of star clusters are not homogeneous but show well defined clumps in observations as well as in numerical simulations. Recently an epicyclic theory for the formation of these clumps was presented. A quantitative analysis was still missing. We present a quantitative derivation of the angular momentum and energy distribution of escaping stars from
L. Traldi, L. Zulli
A knot diagram has an associated looped interlacement graph, obtained from the intersection graph of the Gauss diagram by attaching loops to the vertices that correspond to negative crossings. This construction suggests an extension of the Kauffman bracket to an invariant of looped graphs, and an extension of Reidemeister equivalence to an equivalence relati
Georg Schumacher
Given an effectively parameterized family of canonically polarized manifolds the Kaehler-Einstein metrics on the fibers induce a hermitian metric on the relative canonical bundle. We use a global elliptic equation to show that this metric is strictly positive. For degenerating families we obtain a singular hermitian metric. Main application is an analytic pr
Moustapha Diaby
In this paper, we present a new, graph-based modeling approach and a polynomial-sized linear programming (LP) formulation of the Boolean satisfiability problem (SAT). The approach is illustrated with a numerical example.
Reza Rezazadegan
We generalize the "symplectic Khovanov cohomology" of Seidel and Smith to tangles using the notion of symplectic valued topological field theory introduced by Wehrheim and Woodward.
Deducing the nature of dark matter from direct and indirect detection experiments in the absence of collider signatures of new physics
hep-phMaria Beltran, Dan Hooper, Edward W. Kolb, Zosia C. Krusberg
Despite compelling arguments that significant discoveries of physics beyond the standard model are likely to be made at the Large Hadron Collider, it remains possible that this machine will make no such discoveries, or will make no discoveries directly relevant to the dark matter problem. In this article, we study the ability of astrophysical experiments to
F. Impens, Ch. J. Bordé
The best clocks to date control the atomic motion by trapping the sample in an optical lattice and then interrogate the atomic transition by shining on these atoms a distinct laser of controlled frequency. In order to perform both tasks simultaneously and with the same laser field, we propose to use instead the levitation of a Bose-Einstein condensate throug
John F. Gibson, Jonathan Halcrow, Predrag Cvitanović
We present ten new equilibrium solutions to plane Couette flow in small periodic cells at low Reynolds number (Re) and two new traveling-wave solutions. The solutions are continued under changes of Re and spanwise period. We provide a partial classification of the isotropy groups of plane Couette flow and show which kinds of solutions are allowed by each iso
Christian S. Fischer, Richard Williams
We investigate hadronic unquenching effects in light quarks and mesons. To this end we take into account the back-coupling of the pion onto the quark propagator within the non-perturbative continuum framework of Schwinger-Dyson equations (SDE) and Bethe-Salpeter equations (BSE). We improve on a previous approach by explicitly solving both the coupled system
Zhao Zhang, Kenji Fukushima, Teiji Kunihiro
We investigate the effect of the electric-charge neutrality in $β$ equilibrium on the chiral phase transition by solving the chiral and diquark condensates in the two-flavor Nambu--Jona-Lasinio model. We demonstrate that the electric-charge neutrality plays a similar role as the repulsive vector interaction; they both weaken the first-order chiral phase tran
Mihajlo Vanevic, Yuli V. Nazarov, Wolfgang Belzig
We determine charge transfer statistics in a quantum conductor driven by a time-dependent voltage and identify the elementary transport processes. At zero temperature unidirectional and bidirectional single charge transfers occur. The unidirectional processes involve electrons injected from the source terminal due to excess dc bias voltage. The bidirectional
F. C. Lombardo, F. D. Mazzitelli, P. I. Villar
We numerically evaluate the Casimir interaction energy for configurations involving two perfectly conducting eccentric cylinders and a cylinder in front of a plane. We consider in detail several special cases. For quasi-concentric cylinders, we analyze the convergence of a perturbative evaluation based on sparse matrices. For concentric cylinders, we obtain
J. Luis Miramontes
A systematic group theoretical formulation of the Pohlmeyer reduction is presented. It provides a map between the equations of motion of sigma models with target-space a symmetric space M=F/G and a class of integrable multi-component generalizations of the sine-Gordon equation. When M is of definite signature their solutions describe classical bosonic string
C. H. Yeung, K. Y. Michael Wong
We apply statistical physics to study the task of resource allocation in random sparse networks with limited bandwidths for the transportation of resources along the links. Useful algorithms are obtained from recursive relations. Bottlenecks emerge when the bandwidths are small, causing an increase in the fraction of idle links. For a given total bandwidth p
Azimuthally-sensitive femtoscopy from RHIC to LHC in hydrodynamics with statistical hadronization
nucl-thAdam Kisiel, Wojciech Broniowski, Mikolaj Chojnacki, Wojciech Florkowski
Azimuthally-sensitive femtoscopy for heavy-ion collisions at RHIC and LHC is explored within the approach consisting of the hydrodynamics of perfect fluid followed by statistical hadronization. It is found that for the RHIC initial conditions the very same framework that reproduces the standard soft observables (including the transverse-momentum spectra, the
Charles D. Dermer, Justin D. Finke, Hannah Krug, Markus Boettcher
We extend a method for modeling synchrotron and synchrotron self-Compton radiations in blazar jets to include external Compton processes. The basic model assumption is that the blazar radio through soft X-ray flux is nonthermal synchrotron radiation emitted by isotropically-distributed electrons in the randomly directed magnetic field of outflowing relativis
R. Toivonen, X. Castelló, V. M. Eguíluz, J. Saramäki
We search for conditions under which a characteristic time scale for ordering dynamics towards either of two absorbing states in a finite complex network of interactions does not exist. With this aim, we study random networks and networks with mesoscale community structure built up from randomly connected cliques. We find that large heterogeneity at the meso
Sami Dib, Roberto Galvan-Madrid, Jongsoo Kim, Enrique Vazquez-Semadeni
In this paper, we review some of the properties of dense molecular cloud cores. The results presented here rely on three-dimensional numerical simulations of isothermal, magnetized, turbulent, and self-gravitating molecular clouds (MCs) in which dense core form as a consequence of the gravo-turbulent fragmentation of the clouds. In particular we discuss issu
Sharp optical phonon softening close to optimal doping in La$_{2-x}$Ba$_x$CuO$_{4+δ}$
cond-mat.str-elMatteo D'Astuto, Guy Dhalenne, Jeff Graf, Moritz Hoesch
We report a direct observation of a sharp Kohn-like anomaly in the doubly degenerate copper-oxygen bond-stretching phonon mode occurring at $\mathbf{q}\mathrm{=(0.3, 0,0)}$ in La$_{2-x}$Ba$_x$CuO$_{4+δ}$ with $\mathrm{x=0.14\pm0.01}$, thanks to the high $\mathbf{Q}$ resolution of inelastic x-ray scattering. This anomaly is clearly seen when the inelastic sig
Same-sign top pair production in an extra-dimension model of flavor at the CERN Large Hadron Collider
hep-phJun Gao, Chong Sheng Li, Xiangdong Gao, Zhao Li
We study the same-sign top pair production mediated by the first Kluza-Klein (KK) excitation of the gluon in the Randall-Sundrum (RS) model with flavor violation at the Large Hadron Collider (LHC), in which the nonuniversal couplings between fermions and KK gauge bosons will lead to observable tree level flavor-changing neutral current (FCNC) effects. We fin
M. J. Graf, A. V. Balatsky, Z. Nussinov, I. Grigorenko
Solid He-4 is viewed as a nearly perfect Debye solid. Yet, recent calorimetry measurements by the PSU group (J. Low Temp. Phys. 138, 853 (2005) and Nature 449, 1025 (2007)) indicate that at low temperatures the specific heat has both cubic and linear contributions. These features appear in the same temperature range where measurements of the torsional oscill
D. Aristizabal Sierra, Jisuke Kubo, D. Restrepo, Daijiro Suematsu
Extending the standard model with three right-handed neutrinos ($N_k$) and a second Higgs doublet ($η$), odd under the discrete parity symmetry $Z_2$, Majorana neutrino masses can be generated at 1-loop order. In the resulting model, the lightest stable particle, either a boson or a fermion, might be a dark matter candidate. Here we assume a specific mass sp
Random walker in a temporally deforming higher-order potential forces observed in financial crisis
q-fin.STKota Watanabe, Hideki Takayasu, Misako Takayasu
Basic peculiarities of market price fluctuations are known to be well described by a recently developed random walk model in a temporally deforming quadric potential force whose center is given by a moving average of past price traces [Physica A 370, pp91-97, 2006]. By analyzing high-frequency financial time series of exceptional events such as bubbles and c
A. A. Bannykh, J. Pfeiffer, V. S. Stolyarov, I. E. Batov
The dependence of the critical current density j_c on the ferromagnetic interlayer thickness d_F was determined for Nb/Al_2O_3/Cu/Ni/Nb Josephson tunnel junctions with ferromagnetic \Ni interlayer from very thin film thicknesses (\sim 1 nm) upwards and classified into F-layer thickness regimes showing a dead magnetic layer, exchange, exchange + anisotropy an
Chengming Bai
We construct an associative algebra with a decomposition into the direct sum of the underlying vector spaces of another associative algebra and its dual space such that both of them are subalgebras and the natural symmetric bilinear form is invariant or the natural antisymmetric bilinear form is a Connes cocycle. The former is called a double construction of
Claudia Pinzari, John E. Roberts
We use a tensor C*-category with conjugates and two quasitensor functors into the category of Hilbert spaces to define a *-algebra depending functorially on this data. If one of them is tensorial, we can complete in the maximal C*-norm. A particular case of this construction allows us to begin with solutions of the conjugate equations and associate ergodic a
Dejan D. Dukaric, Stefan Wolf
Non-local correlations are not only a fascinating feature of quantum theory, but an interesting resource for information processing, for instance in communication-complexity theory or cryptography. An important question in this context is whether the resource can be distilled: Given a large amount of weak non-local correlations, is there a method to obtain s
Andreas Barth, Werner Marx
We have carried out a scientometric analysis of the literature dealing with graphene, a material which has been identified as a new carbon allotrope. The investigation is based on the CAplus database of Chemical Abstracts Service, the INSPEC database of the Institute of Electrical and Electronics Engineers and the Web of Science (WoS) of Thomson Reuters. The
Claude Duhr, Fabio Maltoni
QCD amplitudes display a universal behaviour when one or more partons are soft and/or collinear. This can expressed in terms of antenna functions which are much simpler than the full amplitudes and yet correctly embody their infrared behaviour. We show how antenna functions can be naturally obtained via a twistor-inspired MHV approach. As an application, we
Zhen Ouyang, Ju-Jun Xie, Bing-Song Zou, Hu-Shan Xu
New measurement by CELSIUS-WASA Collaboration on the pp->pn pi+ reaction reveals clear evidence for the presence of the Roper resonance N*(1440) which has been ignored in previous theoretical calculations. In this article, based on an effective Lagrangian approach and available knowledge on the Roper resonance, we investigate the role of the Roper resonance
Comprehensive Analysis of Neutrinos in SK part II -- L/E Analysis for Single Ring Muon Events I --
hep-exE. Konishi, Y. Minorikawa, V. I. Galkin, M. Ishiwata
By referring to the procedures developed in the preceeding paper, we re-analyze the L/E distribution for Fully Contained Events resulting from quasi-elatic scattering (QEL) obtained from the Super-Kamiokande Experiment in relation to their assumption that the direction of the incident neutrino coincide with that of the produced leptons. As the result of it,
Krishnendu Gongopadhyay
Using the representation of the isometries as 2x2 invertible matrices over the division algebra $\H$ of quaternions, we give an algebraic characterization of the dynamical types of the orientation-preserving isometries of the hyperbolic 5-space. We also determine the conjugacy classes and the conjugacy classes of centralizers or the z-classes in $GL(2, \H)$.
Naokata Shikuma, Atsushi Igarashi
Tse and Zdancewic have formalized the notion of noninterference for Abadi et al.'s DCC in terms of logical relations and given a proof of noninterference by reduction to parametricity of System F. Unfortunately, their proof contains errors in a key lemma that their translation from DCC to System F preserves the logical relations defined for both calculi.
Tiberiu Harko, Zoltán Kovács, Francisco S. N. Lobo
In this paper, we study the physical properties and characteristics of matter forming thin accretion disks in static and spherically symmetric wormhole spacetimes. In particular, the time averaged energy flux, the disk temperature and the emission spectra of the accretion disks are obtained for these exotic geometries, and are compared with the Schwarzschild
Naihuan Jing
We give a one-to-one correspondence between classes of density matrices under local unitary invariance and the double cosets of unitary groups. We show that the interrelationship among classes of local unitary equivalent multi-partite mixed states is independent from the actual values of the eigenvalues and only depends on the multiplicities of the eigenvalu
Confirmation Bias and the Open Access Advantage: Some Methodological Suggestions for the Davis Citation Study
cs.DLStevan Harnad
Davis (2008) analyzes citations from 2004-2007 in 11 biomedical journals. 15% of authors paid to make them Open Access (OA). The outcome is a significant OA citation Advantage, but a small one (21%). The author infers that the OA advantage has been shrinking yearly, but the data suggest the opposite. Further analyses are necessary: (1) Not just author-choice
Effects of an oscillating field on magnetic domain patterns: Numerical and theoretical studies on the concentric-ring patterns surrounding a strong defect
cond-mat.stat-mechKazue Kudo
Oscillating fields can make domain patterns change into various types of structures. Numerical simulations show that concentric-ring domain patterns centered at a strong defect are observed under a rapidly oscillating field in some cases. The concentric-ring pattern appears near the threshold of spatially-uniform patterns in high-frequency cases. The thresho
Laura Mersini-Houghton, Adam Kelleher
The equation of state (EoS) of dark energy $w$ remains elusive despite enormous experimental efforts to pin down its value and its time variation. Yet it is the single most important handle we have in our understanding of one of the most mysterious puzzle in nature, dark energy. This letter proposes a new method for measuring the EoS of dark energy by using
Phaedon-Stelios Koutsourelakis
This paper proposes a novel uncertainty quantification framework for computationally demanding systems characterized by a large vector of non-Gaussian uncertainties. It combines state-of-the-art techniques in advanced Monte Carlo sampling with Bayesian formulations. The key departure from existing works is the use of inexpensive, approximate computational mo
Avi Mintz
Let $S$ be a finite semigroup. In this paper we introduce the functions $ϕ_s:S^* \to S^*$, first defined by Rhodes, given by $ϕ_s([a_1,a_2 ,...,a_n]) = [sa_1,sa_1a_2,..., sa_1a_2 ... a_n]$. We show that if $S$ is a finite aperiodic semigroup, then the semigroup generated by the functions $\{ϕ_s\}_{s \in S}$ is finite and aperiodic.
V. V. Makarov, N. Zacharias, G. S. Hennessy
A set of 41 nearby stars (closer than 25 pc) is investigated which have very wide binary and common proper motion (CPM) companions at projected separations between 1000 and $200 000$ AU. These companions are identified by astrometric positions and proper motions from the NOMAD catalog. Based mainly on measures of chromospheric and X-ray activity, age estimat
Complete Constant Mean Curvature surfaces and Bernstein type Theorems in $\mathbb{M}^2\times \mathbb{R}$
math.DGJose M. Espinar, Harold Rosenberg
In this paper we study constant mean curvature surfaces $Σ$ in a product space, $\mathbb{M}^2\times \mathbb{R}$, where $\mathbb{M}^2$ is a complete Riemannian manifold. We assume the angle function $ν= \meta{N}{\partial_t}$ does not change sign on $Σ$. We classify these surfaces according to the infimum $c(Σ)$ of the Gaussian curvature of the projection of $
Objects In Telescope Are Farther Than They Appear: How diffraction tricked Galileo into mismeasuring the distances to the stars
physics.hist-phChristopher M. Graney
Galileo determined distances to stars based on the assumption that stars were suns, the apparent sizes of stars as seen through his telescope, and basic geometry. However, the apparent sizes that he measured were the result of diffraction and not related to the actual sizes of the stars. Galileo's methods and observations were good, but since he was unkn
Near-isotropic performance of intrinsically anisotropic high-temperature superconducting tapes due to self-assembled nanostructures
cond-mat.supr-conY. L. Zuev, D. K. Christen, S. H. Wee, A. Goyal
High-temperature superconductors (HTS) are finding use as high - current wires for potential application in power devices. The dependence of their basal-plane critical current properties on orientation in a magnetic field can pose important design problems. Here we report material and operating parameter conditions where prototype HTS tape conductors exhibit
Omer Offen, Eitan Sayag
The SL(2)-type of any smooth, irreducible and unitarizable representation of GL(n) over a p-adic field was defined by Venkatesh. We provide a natural way to extend the definition to all smooth and irreducible representations. For unitarizable representations we show that the SL(2)-type of a representation is preserved under base change with respect to any fi
Ju-Yi Yen, Marc Yor
As a complement to some recent work by Pal and Protter, "Strict local martingales, bubbles, and no early exercise", we show that the call option prices associated with the Bessel strict local martingales are integrable over time, and we discuss the probability densities obtained thus.
Gary M. Bernstein
We present a framework for analyzing weak gravitational lensing survey data, including lensing and source-density observables, plus spectroscopic redshift calibration data. All two-point observables are predicted in terms of parameters of a perturbed Robertson-Walker metric, making the framework independent of the models for gravity, dark energy, or galaxy p
Wei Wu, Nilesh B. Dave, Naftali Kaminski
Motivation: Time course data obtained from biological samples subject to specific treatments can be very useful for revealing complex and novel biological phenomena. Although an increasing number of time course microarray datasets becomes available, most of them contain few biological replicates and time points. So far there are few computational methods tha
Unconventional superconductivity of NdFeAsO0.82F0.18 indicated by the low temperature dependence of the lower critical field Hc1
cond-mat.supr-conX. L. Wang, S. X. Dou, Zhi-An Ren, Wei Yi
We measured the initial M-H curves for a sample of the newly discovered superconductor NdFeAsO0.82Fe0.18, which had a critical temperature, Tc, of 51 K, and was fabricated at the high pressure of 6 GPa. The lower critical field, Hc1, was extracted from the deviation point of the Meissner linearity in the M-H curves, which show linear temperature dependence i
Xiaoming Sun, Zhuang Liu, Kevin Welsher, Joshua Tucker Robinson
Two-dimensional graphene offers interesting electronic, thermal and mechanical properties that are currently explored for advanced electronics, membranes and composites. Here we synthesize and explore the biological application of nano-graphene oxide NGO, single-layer graphene oxide sheets down to a few nanometers in lateral width. We develop functionalizati
Juan M. Pedrosa, Miguel Hoyuelos, Carlos Martel
Order parameter equations, such as the complex Swift-Hohenberg (CSH) equation, offer a simplified and universal description that hold close to an instability threshold. The universality of the description refers to the fact that the same kind of instability produces the same order parameter equation. In the case of lasers, the instability usually corresponds
Mostafa Bendahmane, Raimund Brger, Ricardo Ruiz Baier, José Miguel Urbano
This paper addresses the existence and regularity of weak solutions for a fully parabolic model of chemotaxis, with prevention of overcrowding, that degenerates in a two-sided fashion, including an extra nonlinearity represented by a $p$-Laplacian diffusion term. To prove the existence of weak solutions, a Schauder fixed-point argument is applied to a regula
C. F. Bender, M. Simon
We have observed a large sample of spectroscopic binary stars in the Hyades Cluster, using high resolution infrared spectroscopy to detect low mass companions. We combine our double-lined infrared measurements with well constrained orbital parameters from visible light single-lined observations to derive dynamical mass ratios. Using these results, along with
N. Gehrels, S. D. Barthelmy, D. N. Burrows, J. K. Cannizzo
Correlation studies of prompt and afterglow emissions from gamma-ray bursts (GRBs) between different spectral bands has been difficult to do in the past because few bursts had comprehensive and intercomparable afterglow measurements. In this paper we present a large and uniform data set for correlation analysis based on bursts detected by the Swift mission.
N. G. Stefanis, I. O. Cherednikov
We discuss recent developments in the understanding of gauge-invariant transverse-momentum dependent (TMD) parton-distribution functions (PDF). We compute the leading-order $\overline{\text{MS}\vphantom{^1}}$-scheme anomalous dimension of such a quantity in the light-cone gauge and show that it receives a contribution that can be associated with a cusp obstr
Bernhard Heim
The object of this work is the spinor L-function of degree 3 and certain degeneration related to the functoriality principle. We study liftings of automorphic forms on the pair of symplectic groups $(\text{GSp}(2),\text{GSp}(4))$ to $\text{GSp}(6)$. We prove cuspidality and demonstrate the compatibility with conjectures of Andrianov, Panchishkin, Deligne and
P. V. Ratnikov, A. P. Silin
We consider the energy spectrum of the planar quantum well which consisted of two ribbons of narrow-gap semiconductors and a graphene ribbon between ones. It is shown that the gapless mode appears only in case of inverted narrow-gap semiconductors. Spin splitting of the energy spectrum for a nonsymmetric quantum well is calculated taking into account a speci
Jacob D. Stevenson, Peter G. Wolynes
Dynamics near the surface of glasses is generally much faster than in the bulk. Neglecting static perturbations of structure at the surface, we use random first order transition theory to show the free energy barrier for activated motion near a free surface should be half that of the bulk at the same temperature. The increased mobility allows the surface lay
Scott J. Wolk, Tyler L. Bourke, Miquela Vigil
RCW~38 is a uniquely young ($<$1 Myr), embedded ($A_V \sim 10$) stellar cluster surrounding a pair of early O stars ($\sim$O5.5) and is one of the few regions within 2 kpc other than Orion to contain over 1000 members. X-ray and deep near-infrared observations reveal a dense cluster with over 200 X-ray sources and 400 infrared sources embedded in a diffuse h
Scott J. Wolk, Fernando Comeron, Tyler Bourke
The Ara OB1a association is one of the closest sites where triggered star formation is visible for multiple generations of massive stars. At about 1.3 kpc distance, it contains complex environments including cleared young clusters, embedded infrared clusters, CO clouds with no evidence of star formation, and clouds with evidence of ongoing star formation. In
Kenji Fukushima, Dmitri E. Kharzeev, Harmen J. Warringa
Topological charge changing transitions can induce chirality in the quark-gluon plasma by the axial anomaly. We study the equilibrium response of the quark-gluon plasma in such a situation to an external magnetic field. To mimic the effect of the topological charge changing transitions we will introduce a chiral chemical potential. We will show that an elect
D. Dudal, S. P. Sorella, N. Vandersickel, H. Verschelde
In previous works, we have shown that the Gribov-Zwanziger action, which implements the restriction of the domain of integration in the path integral to the Gribov region, generates extra dynamical effects which influence the infrared behaviour of the gluon and ghost propagator in SU(N) Yang-Mills gauge theories. The latter are in good agreement with the mos
Identifying Deficiencies of Standard Accretion Disk Theory: Lessons from a Mean-Field Approach
astro-phAlexander Hubbard, Eric G. Blackman
Turbulent viscosity is frequently used in accretion disk theory to replace the microphysical viscosity in order to accomodate the observational need for in- stabilities in disks that lead to enhanced transport. However, simply replacing the microphysical transport coefficient by a single turbulent transport coeffi- cient hides the fact that the procedure sho
M. Ajello, J. Greiner, G. Sato, D. R. Willis
We use Swift/BAT Earth occultation data at different geomagnetic latitudes to derive a sensitive measurement of the Cosmic X-ray background (CXB) and of the Earth albedo emission in the 15--200 keV band. We compare our CXB spectrum with recent (INTEGRAL, BeppoSAX) and past results (HEAO-1) and find good agreement. Using an independent measurement of the CXB
Alexander Kuznetsov
United classification of gamma-ray bursts and their counterparts is established on the basis of measured characteristics: photon energy E and emission duration T. The founded interrelation between the mentioned characteristics of events consists in that, as the energy increases, the duration decreases (and vice versa). The given interrelation reflects the na
Ralph Neuhäuser, Jan Forbrich
At a distance of about 130 pc, the Corona Australis molecular cloud complex is one of the nearest regions with ongoing and/or recent star formation. It is a region with highly variable extinction of up to AV~45 mag, containing, at its core, the Coronet protostar cluster. There are now 55 known optically detected members, starting at late B spectral types. At
Pierre Carrier, João F. Justo, Renata M. Wentzcovitch
The quasiharmonic approximation (QHA), in its simplest form also called the statically constrained (SC) QHA, has been shown to be a straightforward method to compute thermoelastic properties of crystals. Recently we showed that for non-cubic solids SC-QHA calculations develop deviatoric thermal stresses at high temperatures. Relaxation of these stresses lead
Darren D. Price
One of the first physics results to come out of ATLAS will be an analysis of J/psi and Upsilon production at 14 TeV. I give an overview of the motivation for looking at the theoretical model underlying quarkonium production, ATLAS expected performance and rates for quarkonium reconstruction and ability to separate out various proposed production models with
S. Schippers
The relevance of storage-ring electron-ion recombination experiments for astrophysics is outlined. In particular, the role of low-energy dielectronic-recombination resonances is discussed. A bibliographic compilation of electron-ion recombination measurements with cosmically abundant ions is provided.
Carlos A. O. Torres, Germano R. Quast, Claudio H. F. Melo, Michael F. Sterzik
A significant population of stars with ages younger than the Pleiades exists in the solar neighborhood. They are grouped in loose young associations, sharing similar kinematical and physical properties, but, due to their vicinity to the Sun, they are dispersed in the sky, and hard to identify. Their strong stellar coronal activity, causing enhanced X-ray emi
Chia Wei Hsu, Julio Largo, Francesco Sciortino, Francis W. Starr
Functionalization of nanoparticles or colloids is increasingly being used to develop customizable "atoms". Functionalization by attaching single strands of DNA allows for direct control of the binding between nanoparticles, since hybridization of double strands will only occur if the base sequences of single strands are complementary. Nanoparticles a
Stanislaw Drozdz, Jaroslaw Kwapien, Pawel Oswiecimka
Methodology that recently lead us to predict to an amazing accuracy the date (July 11, 2008) of reverse of the oil price up trend is briefly summarized and some further aspects of the related oil price dynamics elaborated. This methodology is based on the concept of discrete scale invariance whose finance-prediction-oriented variant involves such elements as
Josephson current in diffusive multilayer superconductor/ferromagnet/superconductor junctions
cond-mat.supr-conIver B. Sperstad, Jacob Linder, Asle Sudbø
We calculate the Josephson current in a diffusive superconductor/ferromagnet/superconductor junction, where the ferromagnetic region contains multiple layers (or domains). In particular, we study a configuration where there are two layers with an arbitrary relative in-plane magnetization orientation, and also include non-ideal interfaces and arbitrary spin-f
A. Weiss, A. Kovacs, R. Guesten, K. M. Menten
We present large scale 870 micron maps of the nearby starburst galaxies NGC253, NGC4945 and the nearest giant elliptical radio galaxy Centaurus A (NGC 5128) obtained with the newly commissioned Large Apex Bolometer Camera (LABOCA) operated at the APEX telescope. Our continuum images reveal for the first time the distribution of cold dust at a angular resolut
Power-dependent shaping of vortex solitons in optical lattices with spatially modulated nonlinear refractive index
physics.opticsYaroslav V. Kartashov, Victor A. Vysloukh, Lluis Torner
We address vortex solitons supported by optical lattices featuring modulation of both the linear and nonlinear refractive indices. We find that when the modulation is out-of-phase the competition between both effects results in remarkable shape transformations of the solitons which profoundly affect their properties and stability. Nonlinear refractive index
Effects of Strong Correlations on the Zero Bias Anomaly in the Extended Hubbard Model with Disorder
cond-mat.str-elYun Song, S. Bulut, R. Wortis, W. A. Atkinson
We study the effect of strong correlations on the zero bias anomaly (ZBA) in disordered interacting systems. We focus on the two-dimensional extended Anderson-Hubbard model, which has both on-site and nearest-neighbor interactions on a square lattice. We use a variation of dynamical mean field theory in which the diagonal self-energy is solved self-consisten
Aging, rejuvenation and thixotropy in complex fluids. Time-dependence of the viscosity at rest and under constant shear rate or shear stress
cond-mat.softDaniel Quemada
Complex fluids exhibit time-dependent changes in viscosity that have been ascribed to both thixotropy and aging. However, there is no consensus for which phenomenon is the origin of which changes. A novel thixotropic model is defined that incorporates aging. Conditions under which viscosity changes are due to thixotropy and aging are unambiguously defined. V
Yael Naze, Gregor Rauw
Context : The peculiar hot star Theta Car in the open cluster IC2602 is a blue straggler as well as a single-line binary of short period (2.2d). Aims : Its high-energy properties are not well known, though X-rays can provide useful constraints on the energetic processes at work in binaries as well as in peculiar, single objects. Methods : We present the anal
Thomas Bose, Steffen Trimper
We study a stochastic model for tumor cell growth with both multiplicative and additive colored noise as well as a non-zero cross-correlations in between. Whereas the death rate within the logistic model is altered by a deterministic term characterizing immunization, the birth rate is assumed to be stochastically changed due to biological motivated growth pr
Alexander Kuznetsov
We discuss the structure of the derived category of coherent sheaves on cubic fourfolds of three types: Pfaffian cubics, cubics containing a plane and singular cubics, and discuss its relation to the rationality of these cubics.
P. Nowakowski, M. Napiórkowski
The solvation force for the 2D Ising strip is calculated via exact diagonalization of the transfer matrix in two cases: the symmetric case corresponds to identical surface fields, and the antisymmetric case to exactly opposite surface fields. In the symmetric case the solvation force is always negative (attractive) while in the antisymmetric case the solvati
Charm and bottom baryon masses in the combined $1/N_c$ and $1/m_Q$ expansion versus quark model
hep-phC. Semay, F. Buisseret, F. Stancu
A good agreement between a flux tube-based quark model of light baryons (strange and nonstrange) and the $1/N_c$ expansion mass formula has been found in previous studies. In the present work a larger connection is established between the quark model and the $1/N_c$ and $1/m_Q$ expansion method by extending the previous procedure to baryons made of one heavy
Sally Seidel
Results are presented from four CDF analyses involving heavy quark production in proton-antiproton collisions at center of mass energy 1.96 TeV. The shapes of b-jets are found to be broader than inclusive predictions and broader than both PYTHIA and HERWIG defaults. A measurement of the production cross section for psi(2S) is consistent with Run 1 results an
On integrability of Hirota-Kimura type discretizations. Experimental study of the discrete Clebsch system
nlin.SIM. Petrera, A. Pfadler, Yu. B. Suris
R. Hirota and K. Kimura discovered integrable discretizations of the Euler and the Lagrange tops, given by birational maps. Their method is a specialization to the integrable context of a general discretization scheme introduced by W. Kahan and applicable to any vector field with a quadratic dependence on phase variables. According to a proposal by T. Ratiu,
Vladas Sidoravicius, Alain-Sol Sznitman
We investigate random interlacements on Z^d, d bigger or equal to 3. This model recently introduced in arXiv:0704.2560 corresponds to a Poisson cloud on the space of doubly infinite trajectories modulo time-shift tending to infinity at positive and negative infinite times. A non-negative parameter u measures how many trajectories enter the picture. Our main
G. S. Paraoanu, A. M. Halvari
We have fabricated aluminum single-electron transistors in which the island is not in contact with the substrate. This new type of device, which can be called suspended single-electron transistor (SUSET), displayed well-defined I-V and dI/dV-V features typical for high-quality standard SET's.
E. Algin, U. Agvaanluvsan, M. Guttormsen, A. C. Larsen
Nuclear level densities for $^{56,57}$Fe have been extracted from the primary $γ$-ray spectra using ($^3$He,$^3$He$^{\prime}γ$) and ($^3$He,$αγ$) reactions. Nuclear thermodynamic properties for $^{56}$Fe and $^{57}$Fe are investigated using the experimental level densities. These properties include entropy, Helmholtz free energy, caloric curves, chemical pot
Time Dependent Monochromatic Scattering of Radiation in One Dimensional Media: Analytical and Numerical Solutions
astro-phD. I. Nagirner, S. L. Kirusheva
In order to choose a numerical method for solving the time dependent equations of radiative transport, we obtain an exact solution for the time dependent radiation field in a one dimensional infinite medium with monochromatic, isotropic scattering for sources with an arbitrary spatial distribution and an arbitrary time variation of their power. The Lax-Wendr
Non-Haar $p$-adic wavelets and their application to pseudo-differential operators and equations
math-phA. Yu. Khrennikov, V. M. Shelkovich
In this paper a countable family of new compactly supported {\em non-Haar} $p$-adic wavelet bases in ${\cL}^2(\bQ_p^n)$ is constructed. We use the wavelet bases in the following applications: in the theory of $p$-adic pseudo-differential operators and equations. Namely, we study the connections between wavelet analysis and spectral analysis of $p$-adic pseud
S. N. Andrianov, V. V. Bochkarev, S. M. Kozyrev
Brane model of universe is considered for a particle. Conservation laws inside the brane are obtained. Equation of motion is derived for a particle using variation principle from these conservation laws. This equation includes terms accounting the variation of brane topology. Its solution is obtained at some approximations and dispersion relation for a parti
Luca Ricci, Massimo Robberto, David R. Soderblom
We present the atlas of protoplanetary disks in the Orion Nebula based on the ACS/WFC images obtained for the HST Treasury Program on the Orion Nebula Cluster. The observations have been carried out in 5 photometric filters nearly equivalent to the standard B, V, Halpha, I, and z passbands. Our master catalog lists 178 externally ionized proto-planetary disk
Konstantin Y. Guslienko, Andrei N. Slavin, Vasyl Tiberkevich, Sang-Koog Kim
A spin wave theory explaining experimentally observed frequency splitting of dynamical excitations with azimuthal symmetry of a magnetic dot in a vortex ground state is developed. It is shown that this splitting is a result of the dipolar hybridization of three spin wave modes of a dot having azimuthal indices |m|=1: two high-frequency azimuthal excitation m
Chromospheric magnetic field and density structure measurements using hard X-rays in a flaring coronal loop
astro-phE. P. Kontar, I. G. Hannah, A. L. MacKinnon
A novel method of using hard X-rays as a diagnostic for chromospheric density and magnetic structures is developed to infer sub-arcsecond vertical variation of magnetic flux tube size and neutral gas density.Using Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) X-ray data and the newly developed X-ray visibilities forward fitting technique we f
Jon Henry Sanders
D.R. Woodall's definition of a 'musquash' is extended to that of a 'bi-musquash' and the existence/uniqueness of these is discussed.
Gregory Karagiorgos, Dimitrios Poulakis
Let $G$ be a finite abelian group $G$ with $N$ elements. In this paper we give a O(N) time algorithm for computing a basis of $G$. Furthermore, we obtain an algorithm for computing a basis from a generating system of $G$ with $M$ elements having time complexity $O(M\sum_{p|N} e(p)\lceil p^{1/2}\rceil^{μ(p)})$, where $p$ runs over all the prime divisors of $N
S. Wycech, A. M. Green
Deeply bound KNN, KNNN and KNNNN states are discussed. The effective force exerted by the K meson on the nucleons is calculated with static nucleons. Next the binding energies are obtained by solving the Schrodinger equation or by variational calculations. The dominant attraction comes from the S-wave Lambda(1405) and an additional contribution is due to Sig