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June 2009 arXiv papers — page 14

Showing 1,3011,400 of 5,471 papers

  1. David E. Evans, Mathew Pugh

    We determine spectral measures for some nimrep graphs arising in subfactor theory, particularly those associated with SU(3) modular invariants and subgroups of SU(3). Our methods also give an alternative approach to deriving the results of Banica and Bisch for ADE graphs and subgroups of SU(2) and explain the connection between their results for affine ADE g

  2. Mark Bickford, Robert Constable, Joseph Halpern, Sabina Petride

    To produce a program guaranteed to satisfy a given specification one can synthesize it from a formal constructive proof that a computation satisfying that specification exists. This process is particularly effective if the specifications are written in a high-level language that makes it easy for designers to specify their goals. We consider a high-level spe

  3. Karl Schwede

    Suppose that $X = \Spec R$ is an $F$-finite normal variety in characteristic $p > 0$. In this paper we show that the big test ideal $τ_b(R) = \tld τ(R)$ is equal to $\sum_Δ τ(R; Δ)$ where the sum is over $Δ$ such that $K_X + Δ$ is $\bQ$-Cartier. This affirmatively answers a question asked by various people, including Blickle, Lazarsfeld, K. Lee and K. Smith.

  4. David E. Evans, Mathew Pugh

    Generalizing Jones's notion of a planar algebra, we have previously introduced an A_2-planar algebra capturing the structure contained in the double complex pertaining to the subfactor for a finite SU(3) ADE graph with a flat cell system. We now introduce the notion of modules over an A_2-planar algebra, and describe certain irreducible Hilbert A_2-TL-mo

  5. S. Narison, V. I. Zakharov

    We elaborate on the relation between perturbative and power-like corrections to short-distance sensitive QCD observables. We confront theoretical expectations with explicit perturbative calculations existing in literature. As is expected, the quadratic correction is dual to a long perturbative series and one should use one of them but not both. However, this

  6. Housem Boulmezaoud, Johannes Kellendonk

    We establish direct isomorphisms between different versions of tiling cohomology. The first version is the direct limit of the cohomologies of the approximants in the Anderson-Putnam-Gähler complex, the second is the recently introduced PV-cohomolgy of Bellissard and Savinien and the third is pattern equivariant cohomology. For the last two versions one can

  7. David E. Evans, Mathew Pugh

    We give a diagrammatic presentation of the A_2-Temperley-Lieb algebra. Generalizing Jones' notion of a planar algebra, we formulate an A_2-planar algebra motivated by Kuperberg's A_2-spider. This A_2-planar algebra contains a subfamily of vector spaces which will capture the double complex structure pertaining to the subfactor for a finite SU(3) ADE

  8. David E. Evans, Mathew Pugh

    We determine the cells, whose existence has been announced by Ocneanu, on all the candidate nimrep graphs except $\mathcal{E}_4^{(12)}$ proposed by di Francesco and Zuber for the SU(3) modular invariants classified by Gannon. This enables the Boltzmann weights to be computed for the corresponding integrable statistical mechanical models and provide the frame

  9. Henri Anciaux, Ildefonso Castro

    We describe several families of Lagrangian submanifolds in the complex Euclidean space which are H-minimal, i.e. critical points of the volume functional restricted to Hamiltonian variations. We make use of various constructions involving planar, spherical and hyperbolic curves, as well as Legendrian submanifolds of the odd-dimensional unit sphere.

  10. Lei Chang, Ian C. Cloet, Bruno El-Bennich, Thomas Klahn

    Two basic motivations for an upgraded JLab facility are the needs: to determine the essential nature of light-quark confinement and dynamical chiral symmetry breaking (DCSB); and to understand nucleon structure and spectroscopy in terms of QCD's elementary degrees of freedom. During the next ten years a programme of experiment and theory will be conducte

  11. Nikolay Gromov, Vladimir Kazakov, Pedro Vieira

    We compute the full dimension of Konishi operator in planar N=4 SYM theory it for a wide range of couplings, from weak to strong coupling regime, and predict the subleading terms in its strong coupling asymptotics. For this purpose we solve numerically the integral form of the AdS/CFT Y-system equations for the exact energies of excited states proposed by us

  12. E. M. Shahverdiev, K. A. Shore

    Secure chaos based multiplex communication system scheme is proposed utilizing globally coupled semiconductor lasers with multiple variable time delay optoelectronic feedbacks.

  13. Richard Hind, Ely Kerman

    In this paper we establish new restrictions on symplectic embeddings of certain convex domains into symplectic vector spaces. These restrictions are stronger than those implied by the Ekeland-Hofer capacities. By refining an embedding technique due to Guth, we also show that they are sharp.

  14. F. Krmpotic, A. R. Samana, C. A. Bertulani

    A computer code for quasiparticle random phase approximation-QRPA and projected quasiparticle random phase approximation-PQRPA models of nuclear structure is explained in details. An important application of the code consists in evaluating nuclear matrix elements involved in neutrino-nucleus reactions. As an example, cross section for 56Fe and 12C are calcul

  15. G. Potel, A. Idini, F. Barranco, E. Vigezzi

    We discuss in this paper both the past and the present of two-nucleon transfer reactions, as well as try to foresee the near future of such studies in nuclei, induced by light as well as by heavy ion reactions.

  16. L. Feher, C. Klimcik

    A geometric interpretation of the duality between two real forms of the complex trigonometric Ruijsenaars-Schneider system is presented. The phase spaces of the systems in duality are viewed as two different models of the same reduced phase space arising from a suitable symplectic reduction of the standard Heisenberg double of U(n). The collections of commut

  17. Carl M. Bender, Gregorio Benincasa, Hugh F. Jones

    In a recent Brief Report by Shalaby a new first-order perturbative calculation of the metric operator for an $iϕ^3$ scalar field theory is given. It is claimed that the result is an improvement on a previous calculation by Bender, Brody and Jones because it is local. Unfortunately Shalaby's calculation is not valid because of sign errors.

  18. Sandro Mattarei

    We prove exact asymptotic expansions for the partial sums of the sequences of central binomial coefficients and Catalan numbers, $\sum_{k=0}^n \binom{2k}{k}$ and $\sum_{k=0}^n C_n$. We also obtain closed forms for the polynomials $\sum_{k=0}^{q-1}\binom{2k}{k}x^k$ and $\sum_{k=0}^{q-1}C_kx^k$ over the field of $p$ elements, where $q$ is a power of the prime

  19. Andreas Hochenegger, Nathan Owen Ilten

    We study invariant divisors on the total spaces of the homogeneous deformations of rational complexity-one T-varieties constructed by Ilten and Vollmert. In particular, we identify a natural subgroup of the Picard group for any general fiber of such a deformation, which is canonically isomorphic to the Picard group of the special fiber. This isomorphism pres

  20. Mu-in Park

    Recently Horava proposed a renormalizable gravity theory with higher spatial derivatives in four dimensions which reduces to Einstein gravity with a non-vanishing cosmological constant in IR but with improved UV behaviors. Here, I consider a non-trivial test of the new gravity theory in FRW universe by considering an IR modification which breaks "softly" the

  21. Victor Beresnevich, Vasili Bernik, Friedrich Götze

    We investigate the distribution of real algebraic numbers of a fixed degree having a close conjugate number, the distance between the conjugate numbers being given as a function of their height. The main result establishes the ubiquity of such algebraic numbers in the real line and implies a sharp quantitative bound on their number. Although the main result

  22. Konstantin G. Zloshchastiev

    Starting from a generic generally covariant classical theory we introduce the logarithmic correction to the quantum wave equation. We demonstrate the emergence of the evolution time from the group of automorphisms of the von Neumann algebra governed by this non-linear correction. It turns out that such time parametrization is essentially energy-dependent and

  23. Alberto Franceschini, Giulia Rodighiero, Mattia Vaccari, Stefano Berta

    [abridged] At the end of the Spitzer cryogenic mission and the onset of the Herschel era, we review our current knowledge on galaxy evolution at IR wavelengths. We also develop new tools for the analysis of background fluctuations to constrain source counts in regimes of high confusion. We analyse a large variety of new data on galaxy evolution and high-z so

  24. Houri Ziaeepour

    In this short note we summarize the arguments against a significant back-reaction of inhomogeneities on the acceleration of the Universe. We also present a quick way to access the importance of back-reaction using the Fourier space presentation of inhomogeneities and properties of their power spectrum.

  25. Lihu Xu, Marco Romito

    We prove that the any Markov solution to the 3D stochastic Navier-Stokes equations driven by a mildly degenerate noise (i.e.all but finitely many Fourier modes are forced) is uniquely ergodic. This follows by proving strong Feller regularity and irreducibility.

  26. Vasily Ogryzko

    Application of quantum principles to living cells requires a new approximation of the full quantum mechanical description of intracellular dynamics. We discuss what principal elements any such good approximation should contain. As one such element, the notion of "Catalytic force" Cf is introduced. Cf is the effect of the molecular target of catalysis

  27. Robert Roth, Jeffrey R. Gour, Piotr Piecuch

    The problem of center-of-mass (CM) contaminations in ab initio nuclear structure calculations using configuration interaction (CI) and coupled-cluster (CC) approaches is analyzed. A rigorous and quantitative scheme for diagnosing the CM contamination of intrinsic observables is proposed and applied to ground-state calculations for He-4 and O-16. The CI and C

  28. Niel de Beaudrap

    One-way measurement based quantum computations (1WQC) may describe unitary transformations, via a composition of CPTP maps which are not all unitary themselves. This motivates the following decision problems: Is it possible to determine whether a ``quantum-to-quantum'' 1WQC procedure (having non-trivial input and output subsystems) performs a unitary transfo

  29. Yuri V. Kovchegov, Zhun Lu, Amir H. Rezaeian

    We show that HERA data for the inclusive structure function F_2(x,Q^2) at small Bjorken-x and Q^2 can be reasonably well described by a color-dipole model with an AdS/CFT-inspired dipole-proton cross section. The model contains only three free parameters fitted to data. In our AdS/CFT-based parameterization the saturation scale varies in the range of 1-3 GeV

  30. Ye Li, Frank Petriello, Seth Quackenbush

    We study the potential of the LHC and future low-energy experiments to precisely measure the underlying model parameters of a new Z' boson. We emphasize the complimentary information obtained from both on- and off-peak LHC dilepton data, from the future Q-weak measurement of the weak charge of the proton, and from a proposed measurement of parity violati

  31. Vesko Valov

    A characterization of $\varkappa$-metrizable compacta in terms of extension of functions and usco retractions into superextensions is established.

  32. D. A. Fuhrmann, H. J. Krenner, A. Wixforth, A. Curran

    Temperature dependence and recombination behavior of trapped charge carriers in ZnCdSe/ZnSe multiple quantum wells are investigated employing surface acoustic waves. These weakly perturb the carrier system, but remain highly sensitive even at small conductivities. Using this non-invasive probe we are able to detect persistent photoconductivity minutes after

  33. Kourosh Nozari, Narges Rashidi

    We construct a DGP-inspired braneworld model where induced gravity on the brane is modified in the spirit of $f(R)$ gravity and stringy effects are taken into account by incorporation of the Gauss-Bonnet term in the bulk action. We explore cosmological dynamics of this model and we show that this scenario is a successful alternative for dark energy proposal.

  34. Christian Wiesendanger

    Isometrodynamics (ID), the gauge theory of the group of volume-preserving diffeomorphisms of an "inner" D-dimensional flat space, is tentatively interpreted as a fundamental theory of gravity. Dimensional analysis shows that the Planck length l_P - and through it \hbar and Γ- enters the gauge field action linking ID and gravity in a natural way. Noti

  35. A. Moor, A. F. Volkov, K. B. Efetov

    We analyze non-equilibrium states in a tunnel superconductor-normal metal (NSN) structure in the presence of a tunnel current $I$. We use an approximation of an effective temperature $T$ and calculate the current-voltage I-V characteristics. It is shown that the I-V dependence may have an S-shaped form. We determine nonuniform current $I(x)$ and temperature

  36. David E. Evans, Mathew Pugh

    We complete the realisation by braided subfactors, announced by Ocneanu, of all SU(3)-modular invariant partition functions previously classified by Gannon.

  37. M. Nonino, M. Dickinson, P. Rosati, A. Grazian

    We present deep imaging in the {\em U} band covering an area of 630 arcmin$^{2}$ centered on the southern field of the Great Observatories Origins Deep Survey (GOODS). The data were obtained with the VIMOS instrument at the ESO Very Large Telescope. The final images reach a magnitude limit $U_{lim} \approx 29.8$ (AB, 1$σ$, in a 1\arcsec radius aperture), and

  38. Gyula Fodor, Péter Forgács, Zalán Horváth, Márk Mezei

    It is shown by both analytical methods and numerical simulations that extremely long living spherically symmetric oscillons appear in virtually any real scalar field theory coupled to a massless dilaton (DS theories). In fact such "dilatonic" oscillons are already present in the simplest non-trivial DS theory -- a free massive scalar field coupled to

  39. Mahan Mj

    In this paper we initiate a study of the topological group $PPQI(G,H)$ of pattern-preserving quasi-isometries for $G$ a hyperbolic Poincare duality group and $H$ an infinite quasiconvex subgroup of infinite index in $G$. Suppose $\partial G$ admits a visual metric $d$ with $dim_H < dim_t +2$, where $dim_H$ is the Hausdorff dimension and $dim_t$ is the topolo

  40. J. Wildeshaus

    The purpose of this article is to construct a Hecke-equivariant Chow motive whose realizations equal interior (or intersection) cohomology of Hilbert-Blumenthal varieties with non-constant algebraic coefficients.

  41. M. R. Setare, Elias C. Vagenas

    Motivated by the recent interest in phantom fields as candidates for the dark energy component, we investigate the consequences of the phantom field when is minimally coupled to gravity. In particular, the necessary (but insufficient) conditions for the acceleration and superacceleration of the universe are obtained when the non-minimal coupling term is take

  42. Markus Fulmek

    The purpose of this note is to exhibit clearly how the &#34;graphical condensation&#34; identities of Kuo, Yan, Yeh and Zhang follow from classical Pfaffian identities by the Kasteleyn-Percus method for the enumeration of matchings. Knuth termed the relevant identities &#34;overlapping Pfaffian&#34; identities and the key concept of proof &#34;superpositions

  43. Eric Bousquet, Nicola A. Spaldin, Philippe Ghosez

    The alkaline earth binary oxides adopt a simple rocksalt structure and form an important family of compounds because of their large presence in the earth's mantle and their potential use in microelectronic devices. In comparison to the class of multifunctional ferroelectric perovskite oxides, however, their practical applications remain limited and the emerg

  44. Hao Tong, Ren Xin Xu, Qiu He Peng, Li Ming Song

    Resonant cyclotron scattering (RCS) in pulsar magnetospheres is considered. The photon diffusion equation (Kompaneets equation) for RCS is derived. The photon system is modeled three dimensionally. Numerical calculations show that there exist not only up scattering but also down scattering of RCS, depending on the parameter space. RCS&#39;s possible applicat

  45. Michael Meier, Michael Schmidt, Georg Lausen

    We study the termination problem of the chase algorithm, a central tool in various database problems such as the constraint implication problem, Conjunctive Query optimization, rewriting queries using views, data exchange, and data integration. The basic idea of the chase is, given a database instance and a set of constraints as input, to fix constraint viol

  46. Kari J. Eskola, Hannu Paukkunen, Carlos A. Salgado

    In this talk, we present our recent next-to-leading order (NLO) nuclear parton distribution functions (nPDFs), which we call EPS09. As an extension to earlier NLO analyses, we supplement the deep inelastic scattering and Drell-Yan dilepton data by inclusive midrapidity pion measurements from RHIC in order to reduce the otherwize large freedom in the nuclear

  47. Nikolay G. Moshchevitin, Dmitrii M. Ushanov

    We prove the existence of two-dimensional good lattice points in thick multiplicative subgroups modulo $p$.

  48. Eliran Boksenbojm, Bram Wynants

    In this paper we investigate the use of path-integral formalism and the concepts of entropy and traffic in the context of molecular motors. We show that together with time-reversal symmetry breaking arguments one can find bounds on efficiencies of such motors. To clarify this techinque we use it on one specific model to find both the thermodynamic and the St

  49. V. I. Isakov

    On the basis of the idea of mixing (interaction) between the electron capture and the positron emission channels in the β^+ decay in the cases when both channels are energetically allowed, we attempt to explain oscillations of the K-capture rates that were possibly seen in the recent experiment.

  50. Jonathan L. Feng, Sky T. French, Christopher G. Lester, Yosef Nir

    We propose a method for determining the mass difference between two particles, \slep_1 and \slep_2, that are nearly degenerate, with \Delta{m}, defined as m_2-m_1, being much less than m_1. This method applies when (a) the \slep_1 momentum can be measured, (b) \slep_2 can only decay to \slep_1, and (c) \slep_1 and \slep_2 can be produced in the decays of a c

  51. Matthew Towers, Sarah Scherotzke

    We construct rank varieties for the Drinfel&#39;d double of the Taft algebra and for U_q(sl2). For the Drinfel&#39;d double when n=2 this uses a result which identifies a family of subalgebras that control projectivity of A-modules whenever A is a Hopf algebra satisfying a certain homological condition. In this case we show that our rank variety is homeomorp

  52. K. Belous, M. Shapkin

    The cross sections for the reactions $e^+e^- \to \phi\eta, \quad \phi\eta', \quad \rho\eta, \quad \rho\eta'$ have been measured using a data sample of 516 fb$^{-1}$ collected with the Belle detector at the KEKB asymmetric-energy $e^+e^-$ collider. The corresponding values of the cross sections are: $1.4 \pm 0.4 \pm 0.1$ fb $(\phi\eta)$, $5.3 \pm 1.1 \pm 0.4$

  53. Zhi-Gang Wang

    In this article, we use the light-cone QCD sum rules to relate the $Λ_b$ baryon light-cone distribution amplitudes to the Isgur-Wise function $ξ(ω)$ of the $Λ_b \to Λ_c$ transition, and obtain a simple relation. The numerical value of the Isgur-Wise function $ξ(ω)$ is consistent with the prediction of the QCD sum rules.

  54. Rémi Catellier, Laurent Mazliak

    This paper concerns the emergence of modern mathematical statistics in France after the First World War. Emile Borel&#39;s achievements are presented, and especially his creation of two institutions where mathematical statistics was developed: the {\it Statistical Institute of Paris University}, (ISUP) in 1922 and above all the {\it Henri Poincaré Institute}

  55. Guilhem Lavaux, Benjamin D. Wandelt

    We propose a new definition of cosmic voids based on methods of Lagrangian orbit reconstruction as well as an algorithm to find them in actual data called DIVA. Our technique is intended to yield results which can be modeled sufficiently accurately to create a new probe of precision cosmology. We then develop an analytical model of the ellipticity of voids f

  56. Tao Zhu, Ji-Rong Ren, Ming-Fan Li

    Using the corrected expression of Hawking temperature derived from the tunneling formalism beyond semiclassical approximation developed by \emph{Banerjee} and \emph{Majhi}\cite{beyond}, we calculate the corrected entropy of a high dimensional Schwarzschild black hole and a 5-dimensional Gauss-Bonnet (GB) black hole. It is shown that the corrected entropy for

  57. Edoardo Ballico, Claudio Fontanari

    Let X be a smooth genus g curve equipped with a simple morphism f: X -> C, where C is either the projective line or more generally any smooth curve whose gonality is computed by finitely many pencils. Here we apply a method developed by Aprodu to prove that if g is big enough then X satisfies both Green and Green-Lazarsfeld conjectures. We also partially add

  58. V. V. Kiselev, S. A. Timofeev

    The constraint on the mass of Higgs field in the Standard Model at the minimal interaction with the gravity is derived in the form of lower bound $m_H> 150$ GeV by the strict requirement of decoupling the Higgs boson from the inflation of early Universe: the inflation produced by the Higgs scalar could crucially destroy visible properties of large scale stru

  59. Akira SaiToh, Robabeh Rahimi, Mikio Nakahara

    In the context of the Oppenheim-Horodecki paradigm of nonclassical correlation, a bipartite quantum state is (properly) classically correlated if and only if it is represented by a density matrix having a product eigenbasis. On the basis of this paradigm, we propose a measure of nonclassical correlation by using truncations of a density matrix down to indivi

  60. Eun-Joo Ahn, Ralph Engel, Thomas K. Gaisser, Paolo Lipari

    The cosmic ray interaction event generator Sibyll is widely used in extensive air shower simulations. We describe in detail the properties of Sibyll 2.1 and the differences with the original version 1.7. The major structural improvements are the possibility to have multiple soft interactions, introduction of new parton density functions, and an improved trea

  61. Remi Tailleux

    There exist two central measures of turbulent mixing in turbulent stratified fluids, both caused by molecular diffusion: 1) the dissipation rate D(APE) of available potential energy (APE); 2) the turbulent rate of change Wr,turbulent of background potential energy GPEr. So far, these two quantities have often been regarded as the same energy conversion, name

  62. Lucio Guerberoff

    We prove modularity lifting theorems for l-adic Galois representations of any dimension satisfying a unitary type condition and a Fontaine-Laffaille type condition at l. This extends the results of Clozel, Harris and Taylor, and the subsequent work by Taylor. The proof uses the Taylor-Wiles method, as improved by Diamond, Fujiwara, Kisin and Taylor, applied

  63. J. Prior, A. M. Somoza, M. Ortuno

    We have obtained the universal conductance distribution of two-dimensional disordered systems in the strongly localized limit. This distribution is directly related to the Tracy-Widom distribution, which has recently appeared in many different problems. We first map a forward scattering paths model into a problem of directed random polymers previously solved

  64. Rüdiger Göbel, José L. Rodríguez, Lutz Strüngmann

    In this paper we improve recent results dealing with cellular covers of $R$-modules. Cellular covers (sometimes called co-localizations) come up in the context of homotopical localization of topological spaces. They are related to idempotent cotriples, idempotent comonads or coreflectors in category theory. Recall that a homomorphism of $R$-modules $π: G\to

  65. Shin Kee Chung, Linqing Wen, David Blair, Kipp Cannon

    We report a novel application of graphics processing units (GPUs) for the purpose of accelerating the search pipelines for gravitational waves from coalescing binaries of compact objects. A speed-up of 16 fold has been achieved compared with a single central processing unit (CPU). We show that substantial improvements are possible and discuss the reduction i

  66. Chetana Jain, Biswajit Paul, Anjan Dutta

    4U 1626-67 is an accretion powered X-ray pulsar that shows remarkably stable X-ray luminosity above hours timescale and gradual intensity variation on a few years timescale. Here we report a significant increase in the X-ray intensity in the long term RXTE-ASM light curve of 4U 1626-67. Similar enhancement in the X-ray flux has also been detected in the Swif

  67. Takahiro Kitayama

    Given a circle-valued Morse function of a closed oriented manifold, we prove that Reidemeister torsion over a non-commutative formal Laurent polynomial ring equals the product of a certain non-commutative Lefschetz-type zeta function and the algebraic torsion of the Novikov complex over the ring. This paper gives a generalization of the result of Hutchings a

  68. S. Sahayanathan

    The high resolution image of the jet of the BL Lac object MKN501 in radio, show a limb-brightened feature. An explanation of this feature as an outcome of differential Doppler boosting of jet spine and jet boundary due to transverse velocity structure of the jet requires large viewing angle. However this inference contradicts with the constraints derived fro

  69. Gerald Kaiser

    We derive Huygens&#39; principle for electrodynamics in terms of 4-vector potentials defined as distributions supported on a surface surrounding the charge-current density. By combining the Pauli algebra with distribution theory, a compact and conceptually simple derivation of the Stratton-Chu and Kottler-Franz equations is obtained. These are extended to fr

  70. Shinji Watanabe, Atsushi Tsuruta, Kazumasa Miyake, Jacques Flouquet

    The mechanism of how critical end points of the first-order valence transitions (FOVT) are controlled by a magnetic field is discussed. We demonstrate that the critical temperature is suppressed to be a quantum critical point (QCP) by a magnetic field. This results explain the field dependence of the isostructural FOVT observed in Ce metal and YbInCu_4. Magn

  71. Xiaodong Cao, John Guckenheimer, Laurent Saloff-Coste

    This paper is concerned with properties of maximal solutions of the Ricci and cross curvature flows on locally homogeneous three-manifolds of type SL(2,R). We prove that, generically, a maximal solution originates at a sub-Riemannian geometry of Heisenberg type. This solves a problem left open in earlier work by two of the authors.

  72. Hisanobu Shinya

    In the paper, we first prove a sufficient condition for the Riemann hypothesis which involves the order of magnitude of the partial sum of the Liouville function. Then we show a formula which is curiously related to the proved sufficient condition.

  73. Haibao Duan, Banghe Li

    Let M be the blow--up of a manifold M along a submanifold X. In this paper we present closed formulae for the integral cohomology and the total Chern class of M. As applications we compute the cohomology of the varieties of complete conics and complete quadrices in 3--space, and justify two enumerative results due to Schubert.

  74. Ben Whale

    In his 1973 paper Quillen proved a resolution theorem for the K-Theory of an exact category; his proof was homotopic in nature. By using the main result of a paper by Nenashev, we are able to give an algebraic proof of Quillen&#39;s Resolution Theorem for K_1 of an exact category.

  75. Kurt Jacobs

    Recently Sagawa and Ueda [Phys. Rev. Lett. 100, 080403 (2008)] derived a bound on the work that can be extracted from a quantum system with the use of feedback control. They left open the question of whether this bound could be achieved for every measurement that could be made by the controller. We show that it can, and that this follows straightforwardly fr

  76. Gabriela Jeronimo, Daniel Perrucci

    We present a new positive lower bound for the minimum value taken by a polynomial P with integer coefficients in k variables over the standard simplex of R^k, assuming that P is positive on the simplex. This bound depends only on the number of variables, the degree and the bitsize of the coefficients of P and improves all previous bounds for arbitrary polyno

  77. Gene Abrams, Kulumani M. Rangaswamy, Mercedes Siles Molina

    We investigate the ascending Loewy socle series of Leavitt path algebras $L_K(E)$ for an arbitrary graph $E$ and field $K$. We classify those graphs $E$ for which $L_K(E)=S_λ$ for some element $S_λ$ of the Loewy socle series. We then show that for any ordinal $λ$ there exists a graph $E$ so that the Loewy length of $L_K(E)$ is $λ$. Moreover, $λ\leq ω$ (the f

  78. Naoki Yoshida

    The standard theory of cosmic structure formation posits that the present-day rich structure of the Universe developed through gravitational amplification of tiny matter density fluctuations generated in its very early history. Recent observations of the cosmic microwave background, large-scale structure, and distant supernovae determined the energy content

  79. Jozsef Garai

    Five new correlations between sunspot activity and orbiting position of the Jovian planets are detected. In order to explain these correlations it is suggested that the resonance of the outer planets destabilizes the orbit of Kuiper Belt Objects and generates a cyclical impact frequency on the Sun. The vaporization of the object initiates a shock way disrupt

  80. Jonathan I. Lunine, David P. O&#39;Brien, Sean N. Raymond, Alessandro Morbidelli

    We review the problem of the formation of terrestrial planets, with particular emphasis on the interaction of dynamical and geochemical models. The lifetime of gas around stars in the process of formation is limited to a few million years based on astronomical observations, while isotopic dating of meteorites and the Earth-Moon system suggest that perhaps 50

  81. V. Lora, A. C. Raga, A. Esquivel

    The radiation from newly born stars photoevaporates their parental neutral cloud, leading to the formation of dense clumps that will eventually form stars. We present 3D simulations of the interaction of a neutral cloud with an external ionising radiation field, and compute the angular momenta of these collapsing clumps. The angular momenta of these collapsi

  82. Kevin J. Walsh, Patrick Michel, Derek C. Richardson

    Asteroids are leftover pieces from the era of planet formation that help us understand conditions in the early Solar System. Unlike larger planetary bodies that were subject to global thermal modification during and subsequent to their formation, these small bodies have kept at least some unmodified primordial material from the solar nebula. However, the str

  83. Jonathan Irwin, David Charbonneau, Zachory K. Berta, Samuel N. Quinn

    We report the detection of eclipses in GJ 3236, a bright (I = 11.6) very low mass binary system with an orbital period of 0.77 days. Analysis of light- and radial velocity curves of the system yielded component masses of 0.38 +/- 0.02 and 0.28 +/- 0.02 Msol. The central values for the stellar radii are larger than the theoretical models predict for these mas

  84. G. Romero, J. J. Garcia-Ripoll, E. Solano

    We develop the theory of a metamaterial composed of an array of discrete quantum absorbers inside a one-dimensional waveguide that implements a high-efficiency microwave photon detector. A basic design consists of a few metastable superconducting nanocircuits spread inside and coupled to a one-dimensional waveguide in a circuit QED setup. The arrival of a {\

  85. Rafael Parra, Manuel Saorin

    Given a significative class $F$ of commutative rings, we study the precise conditions under which a commutative ring $R$ has an $F$-envelope. A full answer is obtained when $F$ is the class of fields, semisimple commutative rings or integral domains. When $F$ is the class of Noetherian rings, we give a full answer when the Krull dimension of $R$ is zero and

  86. Jochen Küpper, Frank Filsinger, Gerard Meijer

    Large molecules have complex potential-energy surfaces with many local minima. They exhibit multiple stereo-isomers, even at very low temperatures. In this paper we discuss the different approaches for the manipulation of the motion of large and complex molecules, like amino acids or peptides, and the prospects of state- and conformer-selected, focused, and

  87. Phani K. V. V. Nukala, P. R. C. Kent

    We present an efficient low-rank updating algorithm for updating the trial wavefunctions used in Quantum Monte Carlo (QMC) simulations. The algorithm is based on low-rank updating of the Slater determinants. In particular, the computational complexity of the algorithm is O(kN) during the k-th step compared with traditional algorithms that require O(N^2) comp

  88. W. Liu, S. V. Lototsky

    A parameter estimation problem is considered for a linear stochastic hyperbolic equation driven by additive space-time Gaussian white noise. The damping/amplification operator is allowed to be unbounded. The estimator is of spectral type and utilizes a finite number of the spatial Fourier coefficients of the solution. The asymptotic properties of the estimat

  89. Robert A. Crain, Tom Theuns, Claudio Dalla Vecchia, Vincent R. Eke

    [Abridged] We present the first results of hydrodynamical simulations that follow the formation of galaxies to z=0 in spherical regions of radius ~20 Mpc/h drawn from the Millennium Simulation. The regions have overdensities that deviate by (-2, -1, 0, +1, +2)sigma from the cosmic mean, where sigma is the rms mass fluctuation on a scale of ~20Mpc/h at z=1.5.

  90. Gonzalo Usaj

    An interesting property of zigzag graphene nanoribbons is the presence of edge states which are extended along its borders but localized in the transverse direction. We show that because of this property, electron transport through an externally induced potential well displays two-paths-interference oscillations when subject either to a magnetic or a transve

  91. Hy Trac, Nickolay Y. Gnedin

    The cosmic reionization of hydrogen was the last major phase transition in the evolution of the universe, which drastically changed the ionization and thermal conditions in the cosmic gas. To the best of our knowledge today, this process was driven by the ultra-violet radiation from young, star-forming galaxies and from first quasars. We review the current o

  92. Richard P. Nelson Sijme-Jan Paardekooper

    The gravitational interaction between a protoplanetary disc and planetary sized bodies that form within it leads to the exchange of angular momentum, resulting in migration of the planets and possible gap formation in the disc for more massive planets. In this article, we review the basic theory of disc-planet interactions, and discuss the results of recent

  93. Davide Lazzati

    The degree and the temporal evolution of linear polarization in the prompt and afterglow emission of gamma-ray bursts is a very robust diagnostic of some key features of gamma-ray bursts jets and their micro and macro physics. In this contribution, I review the current status of the theory of polarized emission from GRB jets during the prompt, optical flash,

  94. Yuncheng You

    In this work the existence of a global attractor for the solution semiflow of the coupled two-cell Brusselator model equations is proved. A grouping estimation method and a new decomposition approach are introduced to deal with the challenge in proving the absorbing property and the asymptotic compactness of this type of four-variable reaction-diffusion syst

  95. X. Dai, C. S. Kochanek, G. Chartas, S. Kozlowski

    We use gravitational microlensing of the four images of the z=0.658 quasar RXJ1131-1231 to measure the sizes of the optical and X-ray emission regions of the quasar. The (face-on) scale length of the optical disk at rest frame 400 nm is 1.3 10^15cm, while the half-light radius of the rest frame 0.3-17 keV X-ray emission is 2.3 10^14cm. The formal uncertainti

  96. Jürg Diemand, Ben Moore

    In the standard cosmological model a mysterious cold dark matter (CDM) component dominates the formation of structures. Numerical studies of the formation of CDM halos have produced several robust results that allow unique tests of the hierarchical clustering paradigm. Universal properties of halos, including their mass profiles and substructure properties a

  97. M. Colpi, M. Dotti

    Binary black holes occupy a special place in our quest for understanding the evolution of galaxies along cosmic history. If massive black holes grow at the center of (pre-)galactic structures that experience a sequence of merger episodes, then dual black holes form as inescapable outcome of galaxy assembly. But, if the black holes reach coalescence, then the

  98. Davide Lazzati, Mitchell Begelman

    We study the polarization properties of the prompt emission of gamma-ray bursts produced by fragmented fireballs. Such fireballs, known in the literature under various names, are made by the superposition of many individual blobs, each of which produces a spike in the light curve. The differences between pulses are due both to the intrinsic diversity in the

  99. Nicola Da Rio, Massimo Robberto, David R. Soderblom, Nino Panagia

    We present U, B, V, I broad-band, 6200A TiO medium-band and Halpha photometry of the Orion Nebula Cluster obtained with the WFI imager at the ESO/MPI 2.2 telescope. The nearly-simultaneous observations cover the entire ONC in a field of about 34x34 arcmin. They enable us to determine stellar colors avoiding the additional scatter in the photometry induced by

  100. Svend Domdey, Hans-Jurgen Pirner, Urs Achim Wiedemann

    The scale factor is the effective cross section used to characterize the measured rate of inclusive double dijet production in high energy hadron collisions. It is sensitive to the two-parton distributions in the hadronic projectile. In principle, the scale factor depends on the center of mass energy and on the minimal transverse energy of the jets contribut