October 2006 arXiv papers — page 4

Supriya Das

Study of event by event fluctuations of thermodynamic quantities offer us more insight about the hot and dense matter created in the relativistic heavy ion collisions. In this review the recent results on these studies carried out by the STAR collaboration are presented.

O. Ujsaghy, L. Szunyogh, A. Zawadowski

In several experiments the magnitude of the contribution of magnetic impurities to the Kondo resistivity shows size dependence in mesoscopic samples. It was suggested ten years ago that magnetic surface anisotropy can be responsible for the size dependence in cases where there is strong spin-orbit interaction in the metallic host. The anisotropy energy has t

Rainer Weissauer

We construct a $\bar Q_l$-linear Tannakian category attached to a smooth projective curve C equivalent to the category of finite dimensional $\bar Q_l$-representations Rep(G), where G is $Sp(2g-2,\bar Q_l)$ or $Sl(2g-2,\bar Q_l)$ depending on whether C is hyperelliptic or not.

Jan Vogel, Jérôme Moritz, Olivier Fruchart

We review models for the nucleation of magnetisation reversal, i.e. the formation of a region of reversed magnetisation in an initially magnetically saturated system. For small particles models for collective reversal, either uniform (Stoner-Wohlfarth model) or non-uniform like curling, provide good agreement between theory and experiment. For microscopic ob

Louis Funar, Daniele Ettore Otera

A finitely presented group is weakly geometrically simply connected (wgsc) if it is the fundamental group of some compact polyhedron whose universal covering is wgsc i.e. it has an exhaustion by compact connected and simply connected sub-polyhedra. We show that this condition is almost-equivalent to Brick's qsf property, which amounts to finding an exhau

Ben O'Leary

Supersymmetry without R-parity predicts tree level quark flavor violation. We present a potential signal of single bottom production at electron-positron colliders with energies in the range 6 to 20 GeV. Taking into account rare decay limits it should be detectable with the current BaBar and Belle data samples.

V. Sguera, A. J. Bird, A. J. Dean, A. Bazzano

Context: AXJ1845.0-0433 was discovered by ASCA in 1993 during fast outburst activity characterized by several flares on short timescales. Up to now, the source was not detected again by any X-ray mission. Its optical counterpart is suggested to be an O9.5I supergiant star, which is the only remarkable object found inside the ASCA error box. Aims: To detect a

Arthemy V. Kiselev

An algebraic definition of Gardner's deformations for completely integrable bi-Hamiltonian evolutionary systems is formulated. The proposed approach extends the class of deformable equations and yields new integrable evolutionary and hyperbolic Liouville-type systems. An exactly solvable two-component extension of the Liouville equation is found.

E. H. Hwang, S. Adam, S. Das Sarma

Motivated by a recent experiment reporting on the possible application of graphene as sensors, we calculate transport properties of 2D graphene monolayers in the presence of adsorbed molecules. We find that the adsorbed molecules, acting as compensators that partially neutralize the random charged impurity centers in the substrate, enhance the graphene mobil

David Callan

Sierpinski's triangle is a fractal and the Prouhet-Thue-Morse word is sufficiently chaotic to avoid cubes. Here we observe that there is at least a tenuous connection between them: the Sierpinski triangle is evident in Pascal's triangle mod 2 whose inverse, as an infinite lower-triangular matrix, involves the Prouhet-Thue-Morse word.

K. Dosen, Z. Petric

It is shown that all the assumptions for symmetric monoidal categories flow out of a unifying principle involving natural isomorphisms of the type ${(A\otimes B)\otimes(C\otimes D)\to(A\otimes C)\otimes(B\otimes D)}$, called medial commutativity. Medial commutativity in the presence of the unit object enables us to define associativity and commutativity natu

J. Dyks, B. Rudak, Joanna M. Rankin

Averaged pulse profiles of three nearby pulsars: B1929+10, J0437-4715 and B0950+08 exhibit unusual `double notches'. These W-like looking features consist of two adjacent V-shaped dips that approach each other at increasing observation frequency nuobs roughly at a rate sep \propto nuobs^{-1/2}, where sep is the separation between the notches' minima.

Péter Lévay

Recently it has been observed that the group $E_7$ can be used to describe a special type of quantum entanglement of seven qubits partitioned into seven tripartite systems. Here we show that this curious type of entanglement is entirely encoded into the discrete geometry of the Fano plane. We explicitly work out the details concerning a qubit interpretation

J. Vidal, S. Dusuel, T. Barthel

We discuss the behavior of the entanglement entropy of the ground state in various collective systems. Results for general quadratic two-mode boson models are given, yielding the relation between quantum phase transitions of the system (signaled by a divergence of the entanglement entropy) and the excitation energies. Such systems naturally arise when expand

Oleg Utyuzh, Grzegorz Wilk, Zbigniew Wlodarczyk

The method of numerical symmetrization of state of identical particles proposed by us before is clarified and discussed.

D. Capeta, D. K. Sunko

Three properties of the Edwards-Anderson model with mobile bonds are investigated which are characteristic of kinetic glasses. First is two-time relaxation in aged systems, where a significant difference is observed between spin and bond autocorrelation functions. The spin subsystem does not show two-time behavior, and the relaxation is stretched exponential

S. A. Kruglyak, L. A. Nazarova, A. V. Roiter

We classify regular locally scalar (= orthoscalar) representations of graph $\widetilde{D}_4$ in Hilbert spaces

M. A. Rajabpour, S. Rouhani, A. A. Saberi

We investigate some aspects of the c=-2 logarithmic conformal field theory. These include the various representations related to this theory, the structures which come out of the Zhu algebra and the W algebra related to this theory. We try to find the fermionic representations of all of the fields in the extended Kac table especially for the untwisted sector

Boris Kruglikov, Valentin Lychagin

We establish an efficient compatibility criterion for a system of generalized complete intersection type in terms of certain multi-brackets of differential operators. These multi-brackets generalize the higher Jacobi-Mayer brackets, important in the study of evolutionary equations and the integrability problem. We also calculate Spencer delta-cohomology of g

V. Kurlin

A classical link in 3-space can be represented by a Gauss paragraph encoding a link diagram in a combinatorial way. A Gauss paragraph may code not a classical link diagram, but a diagram with virtual crossings. We present a criterion and a linear algorithm detecting whether a Gauss paragraph encodes a classical link. We describe Wirtinger presentations reali

Yu. A. Troyan, A. V. Beljaev, A. Yu. Troyan, E. B. Plekhanov

The production and properties of the resonances with the strangeness S=+1 in the system of nK+ were studied in the reaction np->npK+K- at the momentum of incident neutrons Pn=(5.20 +/- 0.12)GeV/c. A number of peculiarities were found in the effective mass spectrum of the mentioned above system. Their widths are comparable with the mass resolution. The estima

A. K. Chaudhuri

In jet quenching, a hard QCD parton, before fragmenting into a jet of hadrons, deposits a fraction of its energy in the medium, leading to suppressed production of high-$p_T$ hadrons. The process can generate shock waves. We study the distortion of Mach shock waves due to jet quenching in central Au+Au collisions and its effect on particle production. Finite

R. Cluckers

We give a survey with some explanations but no proofs of the new notion of b-minimality by the author and F. Loeser [b-minimality, J. Math. Log., 7 no. 2 (2007) 195--227, math.LO/0610183]. We compare this notion with other notions like o-minimality, C-minimality, p-minimality, and so on.

Kenzo Inoue, Kentaro Kojima, Koichi Yoshioka

In this letter we study the low-energy phenomenology and cosmological implications of supersymmetric grand unified theory with asymmetric flavor structure, which is suggested by the recent observation of fermion masses and mixing angles. The predictions of the scenario are rather dependent on a Yukawa parameter fixed by group-theoretical argument. A reduced

M. Ogren, G. M. Kavoulakis

We examine bosonic atoms that are confined in a toroidal, quasi-one-dimensional trap, subjected to a random potential. The resulting inhomogeneous atomic density is smoothened for sufficiently strong, repulsive interatomic interactions. Statistical analysis of our simulations show that the gas supports persistent currents, which become more fragile due to th

Gavriel Segre

With a mathematical eye to Matt Visser's multihistory approach to the time-travel-paradoxes of General Relativity, a non relativistic toy model is analyzed in order of characterizing the conditions in which, in such a toy model, causation occurs.

Sébastien Leygnac, Laurent Boireau, Claire Michaut, Thierry Lanz

Radiative shocks (also called supercritical shocks) are high Mach number shock waves that photoionize the medium ahead of the shock front and give rise to a radiative precursor. They are generated in the laboratory using high-energy or high-power lasers and are frequently present in a wide range of astronomical objects. Their modelisation in one dimension ha

Piotr M. Soltan

Quantum families of maps between quantum spaces are defined and studied. We prove that quantum semigroup (and sometimes quantum group) structures arise naturally on such objects out of more fundamental properties. As particular cases we study quantum semigroups of maps preserving a fixed state and quantum commutants of given quantum families of maps.

Gyula Lakos

We examine the validity of certain spectral integral formulas in topological rings. We consider the sign and square-root functions in polymetric rings containing $\frac12$. It turns out that formal analogues of classical transformation kernels and the resolvent identity can be used to understand the situation. In the lack of $\frac12$, the functions $\frac12

V. I. Anisimov, A. O. Shorikov, J. Kuneš

The goal to describe plutonium phases from ``first principles'' calculation methods is complicated by the problem of 5f-electrons localization. While for early actinides (Th, U,Np) standard DFT (Density Functional Theory) description with itinerant 5f-electrons works well for late actinides (Am, Cm) DFT calculations with completely localized (pseudocore) 5f-

Omar Benhar, Davide Meloni

We investigate neutrino-nucleus interactions at energies around 1 GeV. In this regime, the main contributions to the cross sections come from quasi-elastic and $Δ$ production processes. Our formalism, based on the Impulse Approximation is well suited to describe both types of interactions. We focus on a series of important nuclear effects in the interaction

Adrian Paschke

An important problem to be addressed within Event-Driven Architecture (EDA) is how to correctly and efficiently capture and process the event/action-based logic. This paper endeavors to bridge the gap between the Knowledge Representation (KR) approaches based on durable events/actions and such formalisms as event calculus, on one hand, and event-condition-ac

Tanja Gernhard

In a phylogenetic tree, we often don't have information about the time a speciation event (inner node) occured. Under a neutral model for speciation, I develop fast algorithms for calculating the probability that an inner node i is the k-th speciation event. For the Yule and the coalescent model, I develop an edge length estimation as well. Various prope

F. M. Hu, Lan Zhou, Tao Shi, C. P. Sun

This is the first one of a series of our papers theoretically studying the coherent control of photon transmission along the coupled resonator optical waveguide (CROW) by doping artificial atoms for various hybrid structures. We will provide the several approaches correspondingly based on Green function, the mean field method and spin wave theory et al. In t

S. Jordan, R. Aznar Cuadrado, R. Napiwotzki, H. M. Schmid

Weak magnetic field has been searched for on only a small number of white dwarfs. Current estimates for white dwarfs with fields in excess of 1MG are about 10%; according to previous studies this number increases up to about 25% in the kG regime. Our aim is to improve the statistics by a new sample of ten white dwarfs in order to determine the ratio of magne

R. F. Wagenbrunn

I demonstrate how confinement in Coulomb-gauge QCD makes quark-quark states of the color anti-triplet (diquarks) move out of the physical spectrum. Mesons as color singlet quark-antiquark states, on the other hand have finite masses and for highly excited states in the meson spectra effective restoration of chiral symmetry can be observed.

A. Simionescu, H. Böhringer, M. Brüggen, A. Finoguenov

M87 is a key object whose study can reveal the complex phenomena in cooling cores. We use a deep XMM-Newton observation of M87 to produce detailed temperature, pressure and entropy maps in order to analyze the physical processes of cooling cores and of their heating mechanisms. We employed both broad-band fitting and full spectroscopical one-temperature mode

G. Ganbold

The spectrum of two-particle bound states is investigated within a relativistic quantum-field model of interacting quarks and gluons confined analytically. The hadronization process of mesons and glueballs is described by using the Bethe-Salpeter equation. Provided by a minimal set of physical parameters (the quark masses, the coupling constant and the confi

Toshiaki Tanaka

We propose an elegant formulation of parafermionic algebra and parasupersymmetry of arbitrary order in quantum many-body systems without recourse to any specific matrix representation of parafermionic operators and any kind of deformed algebra. Within our formulation, we show generically that every parasupersymmetric quantum system of order p consists of N-f

GianCarlo Ghirardi, Luca Marinatto

We extend the validity of Hardy's nonlocality without inequalities proof to cover the case of special one-parameter classes of non-pure statistical operators. These mixed states are obtained by mixing the Hardy states with a completely chaotic noise or with a colored noise and they represent a realistic description of imperfect preparation processes of (

Massimiliano F. Sacchi

We show how to quantify the optimal tradeoff between the amount of information retrieved by a quantum measurement in estimating an unknown spin coherent state and the disturbance on the state itself, and how to derive the corresponding minimum-disturbing measurement.

Bageshri Karkare, Uday Khedker

The complexity of round robin method of intraprocedural data flow analysis is measured in number of iterations over the control flow graph. Existing complexity bounds realistically explain the complexity of only Bit-vector frameworks which are separable. In this paper we define the complexity bounds for non-separable frameworks by quantifying the interdepend

Xue Zhi Cheng, Ezra Getzler

We show that the sum over planar trees formula of Kontsevich and Soibelman transfers C-infinity structures along a contraction. Applying this result to a cosimplicial commutative algebra A^* over a field of characteristic zero, we exhibit a canonical unital C-infinity structure on Tot(A^*), which is unital if A^* is; in particular, we obtain a canonical C-in

Jerome Buzzi

We introduce "puzzles of quasi-finite type" which are the counterparts of our subshifts of quasi-finite type (Invent. Math. 159 (2005)) in the setting of combinatorial puzzles as defined in complex dynamics. We are able to analyze these dynamics defined by entropy conditions rather completely, obtaining a complete classification with respect to large

Fei Lin, Erik S. Sorensen, Catherine Kallin, A. John Berlinsky

In this paper we present calculations of single-particle excitation spectra of neutral and three-electron-doped Hubbard C$_{60}$ molecules and monolayers from large-scale quantum Monte Carlo simulations and cluster perturbation theory. By a comparison to experimental photoemission, inverse photoemission, and angle-resolved photoemission data, we estimate the

Mao-Zhi Yang

In the $e^+e^-$ annihilation processes $e^+e^-\to D^0\bar{D}^0, D^+D^-$ near or above the threshold of $D\bar{D}$, there are not only the resonance contribution $e^+e^-\to ψ(3770)\to D^0\bar{D}^0, D^+D^-$, but also the continuum contribution through virtual photon directly $e^+e^-\to γ^*\to D^0\bar{D}^0, D^+D^-$. The amplitudes through virtual photon directl

Hiromichi Suetani, Tatsuo Yanagita, Kazuyuki Aihara

We study the dynamics of a reaction-diffusion system composed of two mutually coupled excitable fibers. We focus on the situation in which dynamical properties of the two fibers are not identical because of the parameter difference between the fibers. Using the spatially one-dimensional FitzHugh-Nagumo equations as a model of a single excitable fiber, we sho

Ernesto P. Borges, Daniel O. Cajueiro, Roberto F. S. Andrade

A procedure to characterize chaotic dynamical systems with concepts of complex networks is pursued, in which a dynamical system is mapped onto a network. The nodes represent the regions of space visited by the system, while edges represent the transitions between these regions. Parameters used to quantify the properties of complex networks, including those r

Magdalena Stobińska, G. J. Milburn, Krzysztof Wódkiewicz

We present an effective method of coherent state superposition (cat state) generation using single trapped ion in a Paul trap. The method is experimentally feasible for coherent states with amplitude $α\le 2$ using available technology. It works both in and beyond the Lamb-Dicke regime.

Stephen L. Adler

We discuss aspects of gravitational modifications of Schrodinger dynamics proposed by Diosi and Penrose. We consider first the Diosi-Penrose criterion for gravitationally induced state vector reduction, and compute the reduction time expected for a superposition of a uniform density cubical solid in two positions displaced by a small fraction of the cube sid

Rubens Viana Ramos, Paulo Benicio Melo de Sousa

In this work, we propose two optical setups for two-players, non-zero and zero sum, quantum games in optical networks using light polarization of single-photon pulses, single-photon detectors and linear optical devices. The optical setups proposed can be easily implemented permitting a fast experimental realization of quantum games with present technology.

J. Eisert

This thesis covers several aspects of entanglement in the context of quantum information theory.

Bo-Sture K. Skagerstam, Ulrich Hohenester, Asier Eiguren, Per Kristian Rekdal

This is a reply to the Comment on 'Spin Decoherence in Superconducting Atom Chips' [arXiv:quant-ph/0610095 (2006)].

Lin Chen, Yi-Xin Chen

We propose a scheme of 1$\to$2 optimal universal asymmetric quantum telecloning of pure multiqubit states. In particular, we first investigate the asymmetric telecloning of arbitrary 2-qubit states and then extend it to the case of multiqubit system. Many figures of merit for the telecloning process are checked, including the entanglement of the quantum chan

A. Ganguly, M. V. Ioffe, L. M. Nieto

A new quantum model with rational functions for the potential and effective mass is proposed in a stretchable region outside which both are constant. Starting from a generalized effective mass kinetic energy operator the matching and boundary conditions for the envelope wave functions are derived. It is shown that in a mapping to an auxiliary constant-mass S

Lvjun Li, Daowen Qiu

In probabilistic cloning with two auxiliary systems, we consider and compare three different protocols for the success probabilities of cloning. We show that, in certain circumstances, it may increase the success probability to add an auxiliary system to the probabilistic cloning machine having one auxiliary system, but we always can find another cloning mac

Melissa Duncan, Angela Foerster, Jon Links, Eduardo Mattei

We study a three-mode Hamiltonian modelling a heteronuclear molecular Bose--Einstein condensate. Two modes are associated with two distinguishable atomic constituents, which can combine to form a molecule represented by the third mode. Beginning with a semi-classical analogue of the model, we conduct an analysis to determine the phase space fixed points of t

Robert H. Clewley, John M. Guckenheimer, Francisco J. Valero-Cuevas

Studies of the degrees of freedom or "synergies" in musculoskeletal systems rely critically on algorithms to estimate the "dimension" of kinematic or neural data. Linear algorithms such as principal component analysis (PCA) are used almost exclusively for this purpose. However, biological systems tend to possess nonlinearities and operate at

Anita Scheuber, Rachel Rudge, Lydia Danglot, Graca Raposo

Synaptic vesicle (SV) exocytosis mediating neurotransmitter release occurs spontaneously at low intraterminal calcium concentrations and is stimulated by a rise in intracellular calcium. Exocytosis is compensated for by the reformation of vesicles at plasma membrane and endosomes. Although the adaptor complex AP-3 was proposed to be involved in the formation

Illes J. Farkas, Chuang Wu, Chakra Chennubhotla, Ivet Bahar

BACKGROUND. Signal recognition and information processing is a fundamental cellular function, which in part involves comprehensive transcriptional regulatory (TR) mechanisms carried out in response to complex environmental signals in the context of the cell's own internal state. However, the network topological basis of developing such integrated respons

A. D. Ludlow, X. Huang*, M. Notcutt, T. Zanon

We demonstrate phase and frequency stabilization of a diode laser at the thermal noise limit of a passive optical cavity. The system is compact and exploits a cavity design that reduces vibration sensitivity. The sub-Hz laser is characterized by comparison to a second independent system with similar fractional frequency stability (1 x 10-15 at 1 s). The lase

Josh W. Dunn, J. W. Thomsen, Chris H. Greene, Flavio C. Cruz

We perform a quantitative analysis of the cooling dynamics of three-level atomic systems interacting with two distinct lasers. Employing sparse-matrix techniques, we find numerical solutions to the fully quantized master equation in steady state. Our method allows straightforward determination of laser-cooling temperatures without the ambiguity often accompa

Wojciech Slomczynski, Karol Zyczkowski

Systems of indirect voting based on the principle of qualified majority can be analysed using the methods of game theory. In particular, this applies to the voting system in the Council of the European Union, which was recently a subject of a vivid political discussion. The a priori voting power of a voter measures his potential influence over the decisions

Klaus Gottstein

It is shown that, in contrast to many interpretations in the press, the drafts of Bohr's unsent letters to Heisenberg are not contradicting Heisenberg's description of his famous trip in 1941 to Copenhagen, but are complementary to it.

Kin Hung Fung, C. T. Chan

We demonstrate an efficient eigen-decomposition method for analyzing the guided modes in metal nanoparticle chains. The proposed method has the advantage of showing the dispersion relation and mode quality simultaneously. It can also separate the material and geometrical properties, so its efficiency does not depend on the complexity of the material polariza

T. Fujita, S. Kanamaki, A. Kusaka, S. Oshima

The mystery that the real scalar Klein-Gordon field has vanishing current densities is resolved. The scalar field is shown to be a complex field due to the condition of possessing a proper non-relativistic limit. Like the Schrödinger field, one component complex Klein-Gordon field corresponds to a boson with one flavor, and therefore there exists no physical

Alexandros Alexakis

Marginally unstable Holmboe modes for smooth density and velocity profiles are studied. For a large family of flows and stratification that exhibit Holmboe instability, we show that the modes with phase velocity equal to the maximum or the minimum velocity of the shear are marginally unstable. This allows us to determine the critical value of the control par

S. Mishev, V. V. Voronov

It is well known that the Pauli principle plays a substantial role at low energies because the phonon operators are not ideal boson operators. Calculating the exact commutators between the quasiparticle and phonon operators one can take into account the Pauli principle corrections. Besides the ground state correlations due to the quasiparticle interaction in

Boris Tomasik, Evgeni E Kolomeitsev

We construct a hadronic kinetic model for description of excitation functions of multiplicity ratios K+/pi+, K-/pi-, and Lambda/pi. It is shown that the model is able to describe data rather well under the assumption that the total lifespan of the fireball is decreasing function of the collision energy for SPS energies above 30 AGeV. Thus in order to identif

J. D. Vergados

We review various issues related to the direct detection of constituents of dark matter, which are assumed to be Weakly Interacting Massive Particles (WIMPs). We specifically consider heavy WIMPs such as: 1) The lightest supersymmetric particle LSP or neutralino. 2) The lightest Kaluza-Klein particles in theories of extra dimensions and 3) other extensions o

K. V. Lukyanov, I. N. Kukhtina, V. K. Lukyanov, Yu. E. Penionzhkevich

The existing and some preliminary experimental data on the total cross sections of the $^{4,6}$He, $^{6,7}$Li +$^{28}$Si reactions at energies E=5-50 A MeV are demonstrated. The data on $^{6}$Li,$^{6}$He+$^{28}$Si are analyzed in the framework of the microscopic optical potential with real and imaginary parts obtained with a help of the double-folding proced

H. Ballhausen, H. Abele, R. Gaehler, M. Trapp

We describe a novel experimental technique for neutron imaging with scattered neutrons. These scattered neutrons are of interest for condensed matter physics, because they permit to reveal the local distribution of incoherent and coherent scattering within a sample. In contrast to standard attenuation based imaging, scattered neutron imaging distinguishes be

K. Schweda, X. Zhu, M. Bleicher, S. L. Huang

We propose to measure azimuthal correlations of heavy-flavor hadrons to address the status of thermalization at the partonic stage of light quarks and gluons in high-energy nuclear collisions. In particular, we show that hadronic interactions at the late stage cannot significantly disturb the initial back-to-back azimuthal correlations of DDbar pairs. Thus,

Xavier Leoncini, Olivier Agullo, Magali Muraglia, Cristel Chandre

A numerical method is proposed in order to track field lines of three-dimensional divergence free fields. Field lines are computed by a locally valid Hamiltonian mapping, which is computed using a symplectic scheme. The method is theoretically valid everywhere but at points where the field is null or infinite. For any three dimensional flux conservative fiel

Andreas Balser

For a Euclidean building $X$ of type $A_{2}$, we classify the 0-dimensional subbuildings $A$ of $\partial_{T}X$ that occur as the asymptotic boundary of closed convex subsets. In particular, we show that triviality of the holonomy of a triple (of points of $A$) is (essentially) sufficient. To prove this, we construct new convex subsets as the union of convex

Helge Glockner, George A. Willis

To each totally disconnected, locally compact topological group G and each group A of automorphisms of G, a pseudo-metric space of ``directions'' has been associated by U. Baumgartner and the second author. Given a Lie group G over a local field, it is a natural idea to try to define a map from the space of directions of analytic automorphisms of G t

Antonio Caminha, Henrique de Lima

We derive, for the square operator of Yau, an analogue of the Omori-Yau maximum principle for the Laplacian. We then apply it to obtain nonexistence results concerning complete spacelike hypersurfaces with constant higher order mean curvature in the Steady State space.

Richard Oberlin

We use the arithmetic-combinatorial method of Katz and Tao to give mixed-norm estimates for the x-ray transform on R^d when d \geq 4. As an application, we obtain an improved estimate for the Hausdorff dimension of (d,k) sets, which are subsets of R^d containing a translate of every k-plane.

Margaret M. Bayer, Tibor Bisztriczky

Cyclic polytopes are characterized as simplicial polytopes satisfying Gale's evenness condition (a combinatorial condition on facets relative to a fixed ordering of the vertices). Periodically-cyclic polytopes are polytopes for which certain subpolytopes are cyclic. Bisztriczky discovered a class of periodically-cyclic polytopes that also satisfy Gale&#3

Hubert De Fraysseix, Patrice Ossona De Mendez

We prove that the vertex set of any twin-free multigraph G has an embedding into some point set P of some Euclidean space Rk, such that the automorphism group of G is isomorphic to the isometry group of Rk globally preserving P.

Hubert De Fraysseix, Patrice Ossona De Mendez, Pierre Rosenstiehl

We present a simplified version of the DFS-based Left-Right planarity testing and embedding algorithm implemented in Pigale which has been considered as the fastest implemented one [J.M. Boyer, P.F. Cortese, M. Patrignani, and G. Di Battista. Stop minding your P's and Q's: implementing fast and simple DFS-based planarity and embedding algorithm. In G

O. I. Mokhov

We prove that the associativity equations of two-dimensional topological quantum field theories are very natural reductions of the fundamental nonlinear equations of the theory of submanifolds in pseudo-Euclidean spaces and give a natural class of potential flat torsionless submanifolds. We show that all potential flat torsionless submanifolds in pseudo-Eucl

Genkai Zhang

Let $G_{n,k}(\bbK)$ be the Grassmannian manifold of $k$-dimensional $\bbK$-subspaces in $\bbK^n$ where $\bbK=\mathbb R, \mathbb C, \mathbb H$ is the field of real, complex or quaternionic numbers. For $1\le k < k^\prime \le n-1$ we define the Radon transform $(\mathcal R f)(η)$, $η\in G_{n,k^\prime}(\bbK)$, for functions $f(ξ)$ on $G_{n,k}(\bbK)$ as an integ

wenlian Lu, Tianping Chen

In this paper, we investigate the existence and the global stability of periodic solution for dynamical systems with periodic interconnections, inputs and self-inhibitions. The model is very general, the conditions are quite weak and the results obtained are universal.

Mridul Aanjaneya, Sudebkumar Prasant Pal

In this paper we consider faultfree tromino tilings of rectangles and characterize rectangles that admit such tilings. We introduce the notion of {\it crossing numbers} for tilings and derive bounds on the crossing numbers of faultfree tilings. We develop an iterative scheme for generating faultfree tromino tilings for rectangles and derive the closed form e

René Dáger, Arturo Presa

A differential form defined on a Riemannian manifold is said to harmonic if it is closed and co-closed. Harmonic differential forms are a natural multi-dimensional extension of the concept of analytic function of complex variable. In this paper we characterize continuous linear functionals acting of the space of germs of harmonic differential forms on a comp

Wenlian Lu, Tianping Chen

Research of delayed neural networks with variable self-inhibitions, inter-connection weights, and inputs is an important issue. %In the real world, self-inhibitions, %inter-connection weights, and inputs should vary through time. In In this paper, we discuss a large class of delayed dynamical systems with almost periodic self-inhibitions, inter-connection we

Zhou Wang, Jianlong Chen

A ring $R$ is said to be $n$-clean if every element can be written as a sum of an idempotent and $n$ units. The class of these rings contains clean ring and $n$-good rings in which each element is a sum of $n$ units. In this paper, we show that for any ring $R$, the endomorphism ring of a free $R$-module of rank at least 2 is 2-clean and that the ring $B(R)$

A. M. Vinogradov, L. Vitagliano

For the multiple differential algebra of iterated differential forms (see math.DG/0605113 and math.DG/0609287) on a diffiety (O,C) an analogue of C-spectral sequence is constructed. The first term of it is naturally interpreted as the algebra of secondary iterated differential forms on (O,C). This allows to develop secondary tensor analysis on generic diffie

J. -J. Loeb, M. Manjarin, M. Nicolau

It was shown by Samelson and Wang that each compact Lie group K of even dimension admits left-invariant complex structures. When K has odd dimension it admits a left-invariant CR-structure of maximal dimension. This has been proved recently by Charbonnel and Khalgui who have also given a complete algebraic description of these structures. In this article we

A. M. Vinogradov, L. Vitagliano

Basic elements of integral calculus over algebras of iterated differential forms, are presented. In particular, defining complexes for modules of integral forms are described and the corresponding berezinians and complexes of integral forms are computed. Various applications and the integral calculus over the algebra $Λ_{\infty}$ will be discussed in subsequ

Ryohei Suzuki

We calculated the rational Khovanov homology of some class of pretzel knots, by using the spectral sequence constructed by P. Turner. Moreover, we determined the Rasmussen&#39;s s-invariant of almost of pretzel knots with three pretzels.

Xueliang Li, Jianhua Tu, Zemin Jin

Given two graphs $G$ and $H$, let $f(G,H)$ denote the maximum number $c$ for which there is a way to color the edges of $G$ with $c$ colors such that every subgraph $H$ of $G$ has at least two edges of the same color. Equivalently, any edge-coloring of $G$ with at least $rb(G,H)=f(G,H)+1$ colors contains a rainbow copy of $H$, where a rainbow subgraph of an

Norberto Laghi, Neil Lyall

In this article we study the behavior of strongly singular integrals associated to three different, albeit equivalent, quasi-norms on Heisenberg groups; these quasi-norms give rise to phase functions whose mixed Hessians may or may not drop rank along suitable varieties. In the particular case of the Koranyi norm we improve on previous arguments of the secon

Norberto Laghi, Neil Lyall

We prove sharp $L^2$ regularity results for classes of strongly singular Radon transfoms on the Heisenberg group by means of oscillatory integrals. We show that the problem in question can be effectively treated by establishing uniform estimates for certain oscillatory integrals whose canonical relations project with two-sided fold singularities; this new ap

Ana González, Ernesto Lupercio, Carlos Segovia, Bernardo Uribe

In this paper we prove that for an almost complex orbifold, its virtual orbifold cohomology [math.AT/0606573] is isomorphic as algebras to the Chen-Ruan orbifold cohomology of its cotangent orbifold.

Jing Zhang

We give several new criteria for a quasi-projective variety to be affine. In particular, we prove that an algebraic manifold $Y$ with dimension $n$ is affine if and only if $H^i(Y, Ω^j_Y)=0$ for all $j\geq 0$, $i>0$ and $κ(D, X)=n$, i.e., there are $n$ algebraically independent nonconstant regular functions on $Y$, where $X$ is the smooth completion of $Y$,

Teruji Thomas

Kashiwara defined the Maslov index (associated to a collection of Lagrangian subspaces of a symplectic vector space over a field F) as a class in the Witt group W(F) of quadratic forms. We construct a canonical quadratic vector space in this class and show how to understand the basic properties of the Maslov index without passing to W(F)--that is, more or le

Vitor Araujo

We obtain some results of existence and continuity of physical measures through equilibrium states and apply these to non-uniformly expanding transformations on compact manifolds with non-flat critical sets, obtaining sufficient conditions for continuity of physical measures and, for local diffeomorphisms, necessary and sufficient conditions for stochastic s

Cliff P. Burgess, James M. Cline, Keshav Dasgupta, Hassan Firouzjahi

Back-reaction effects can modify the dynamics of mobile D3 branes moving within type IIB vacua, in a way which has recently become calculable. We identify some of the ways these effects can alter inflationary scenarios, with the following three results: (1) By examining how the forces on the brane due to moduli-stabilizing interactions modify the angular mot