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August 2008 arXiv papers — page 11

Showing 1,001–1,100 of 4,272 papers

  1. Dao Xuan Viet, Hikaru Kawamura

    Ordering of the three-dimensional Heisenberg spin glass with Gaussian coupling is studied by extensive Monte Carlo simulations. The model undergoes successive chiral-glass and spin-glass transitions at nonzero temperatures T_{CG} > T_{SG} > 0, exhibiting the spin-chirality decoupling.

  2. A. Garcia-Varela, G. Pietrzynski, W. Gieren, A. Udalski

    We report on the discovery of a Cepheid population in the Sculptor Group spiral galaxy NGC 247 for the first time. On the basis of wide-field images collected in photometric surveys in V and I bands which were conducted with three different telescopes and cameras, 23 Cepheid variables were discovered with periods ranging from 17 to 131 days. We have construc

  3. J. B. Pors, S. S. R. Oemrawsingh, A. Aiello, M. P. van Exter

    We introduce the concept of Shannon dimensionality D as a new way to quantify bipartite entanglement as measured in an experiment. This is applied to orbital-angular-momentum entanglement of two photons, using two state analyzers composed of a rotatable angular-sector phase plate that is lens-coupled to a single-mode fiber. We can deduce the value of D direc

  4. Detlef Duerr, Sheldon Goldstein, Nino Zanghi

    In a recent article (New Journal of Physics 9, 165, 2007), Wiseman has proposed the use of so-called weak measurements for the determination of the velocity of a quantum particle at a given position, and has shown that according to quantum mechanics the result of such a procedure is the Bohmian velocity of the particle. Although Bohmian mechanics is empirica

  5. Liaofu Luo

    The problem of the directionality of genome evolution is studied. Based on the analysis of C-value paradox and the evolution of genome size we propose that the function-coding information quantity of a genome always grows in the course of evolution through sequence duplication, expansion of code, and gene transfer from outside. The function-coding informatio

  6. S. M. Kozyrev

    Here we are starting the study of the field equations of relativistic scalar tensor theories in the spherically symmetric gravitational field. In the present article we shall consider as an example only the simplest Jordan-Brans-Dicke (JBD) one. To illustrate the property of the spherically symmetric JBD configuration we exhibit a new representation of the w

  7. Frederic Hebert, George G. Batrouni, Xavier Roy, Valery G. Rousseau

    Using quantum Monte Carlo simulations, we study a mixture of bosons and fermions loaded on an optical lattice. With simple on-site repulsive interactions, this system can be driven into a solid phase. We dope this phase and, in analogy with pure bosonic systems, identify the conditions under which the bosons enter a supersolid phase, i.e., exhibiting at the

  8. D. Salart, A. Baas, C. Branciard, N. Gisin

    In science, one observes correlations and invents theoretical models that describe them. In all sciences, besides quantum physics, all correlations are described by either of two mechanisms. Either a first event influences a second one by sending some information encoded in bosons or molecules or other physical carriers, depending on the particular science.

  9. Shoichi Hoshi, Hiroki Saito

    Magnetization dynamics of a half-quantum vortex in a spin-1 Bose-Einstein condensate with a ferromagnetic interaction are investigated by mean-field and Bogoliubov analyses. The transverse magnetization is shown to break the axisymmetry and form threefold domains. This phenomenon originates from the topological structure of the half-quantum vortex and spin c

  10. M. Perucho, I. Agudo, J. L. Gomez, M. Kadler

    We present a possible scenario for the ejection of a superluminal component in the jet of the Broad Line Radio Galaxy 3C111 in early 1996. VLBI observations at 15 GHz discovered the presence of two jet features on scales smaller than one parsec. The first component evolves downstream, whereas the second one fades out after 1 parsec. We propose the injection

  11. Matti Peltomaki, Mikko Alava

    Cyclic dominance of three species is a commonly occurring interaction dynamics, often denoted the rock-paper-scissors (RPS) game. Such type of interactions is known to promote species coexistence. Here, we generalize recent results of Reichenbach et al. (e.g. Nature 448, 1046 (2007)) of a four-state variant of RPS. We show that spiral formation takes place o

  12. Lei Wang, Baowen Li

    Memory is an indispensable element for computer besides logic gates. In this Letter we report a model of thermal memory. We demonstrate via numerical simulation that thermal (phononic) information stored in the memory can be retained for a long time without being lost and more importantly can be read out without being destroyed. The possibility of experiment

  13. Michael Fischer, Gunter Gerbeth, Andre Giesecke, Frank Stefani

    The asymmetric time dependence and various statistical properties of polarity reversals of the Earth's magnetic field are utilized to infer some of the most essential parameters of the geodynamo, among them the effective (turbulent) magnetic diffusivity, the degree of supercriticality, and the relative strength of the periodic forcing which is believed t

  14. Pulak Ranjan Giri

    We study the dynamics of fermions on graphene in presence of Coulomb impurities and Aharonov-Bohm field. Special emphasis is given to the formation of hydrino like states and its lifting of degeneracy due to the presence of AB field. The flux of the AB field can be tuned to make the low angular momentum hydrino states stable against decay. The zero limit phy

  15. M. Akbar

    By employing the general expression of temperature $T_{h}=|κ|/2π= \frac{1}{2π\tilde{r}_{A}}(1-\frac{\dot{\tilde{r}}_{A}}{2H\tilde{r}_{A}})$ associated with the apparent horizon of a FRW universe and assuming a region of FRW universe enclosed by the apparent horizon as a thermal system in equilibrium, we are able to show that the generalized second law of the

  16. Finnur Larusson, Ragnar Sigurdsson

    We prove two disc formulas for the Siciak-Zahariuta extremal function of an arbitrary open subset of complex affine space. We use these formulas to characterize the polynomial hull of an arbitrary compact subset of complex affine space in terms of analytic discs. Similar results in previous work of ours required the subsets to be connected.

  17. Myaing Thi Win, K. Hagino

    We study the deformation property of $Λ$ hypernuclei using the relativistic mean field (RMF) method. We find that $^{29}_Λ$Si and $^{13}_Λ$C hypernuclei have spherical shape as a consequence of the additional $Λ$ particle, whereas the corresponding core nuclei, $^{28}$Si and $^{12}$C, are oblately deformed. Most of other hypernuclei have a similar deformatio

  18. Rémi Rhodes

    We study the long time behavior (homogenization) of a diffusion in random medium with time and space dependent coefficients. The diffusion coefficient may degenerate. In Stochastic Process. Appl. (2007) (to appear), an invariance principle is proved for the critical rescaling of the diffusion. Here, we generalize this approach to diffusions whose space-time

  19. Gert Wrigge, Jaesuk Hwang, Ilja Gerhardt, Gert Zumofen

    We present an experimental comparison and a theoretical analysis of the signal-to-noise ratios in fluorescence and extinction spectroscopy of a single emitter. We show that extinction measurements can be advantageous if the emitter is weakly excited. Furthermore, we discuss the potential of this method for the detection and spectroscopy of weakly emitting sy

  20. D. Pooley, S. Rappaport, J. Blackburne, P. L. Schechter

    We determine the most likely dark-matter fraction in the elliptical galaxy quadruply lensing the quasar PG1115+080 based on analyses of the X-ray fluxes of the individual images in 2000 and 2008. Between the two epochs, the A2 image of PG1115+080 brightened relative to the other images by a factor of six in X-rays. We argue that the A2 image had been highly

  21. J. E. Bunder, Hsiu-Hau Lin

    We derive a Hamiltonian for a two-leg ladder which includes an arbitrary number of charge and spin interactions. To illustrate this Hamiltonian we consider two examples and use a renormalization group technique to evaluate the ground state phases. The first example is a two-leg ladder with zigzagged legs. We find that increasing the number of interactions in

  22. Sean N. Raymond, Rory Barnes, Noel Gorelick

    Five planets are known to orbit the star 55 Cancri. The recently-discovered planet f at 0.78 AU (Fischer et al. 2008) is located at the inner edge of a previously-identified stable zone that separates the three close-in planets from planet d at 5.9 AU. Here we map the stability of the orbital space between planets f and d using a suite of n-body integrations

  23. Yutao Ma, Keqing He, Jing Liu

    Nowadays, software has become a complex piece of work that may be beyond our control. Understanding how software evolves over time plays an important role in controlling software development processes. Recently, a few researchers found the quantitative evidence of structural duplication in software systems or web applications, which is similar to the evoluti

  24. Peng Gao

    We present some results concerning the $l^p$ norms of weighted mean matrices. These results can be regarded as analogues to a result of Bennett concerning weighted Carleman's inequalities.

  25. Mingji Jin, Ping Chen, P. Boolchand, T. Rajagopalan

    Obliquely deposited amorphous Ge_xSe{1-x} thin-films at several compositions in the 0.15 < x < 0.333 range, and at several obliqueness angles in the 0 < alpha < 80 range at each x were evaporated on Si and glass substrates. Here alpha designates the angle between film normal and direction of vapor transport. Raman scattering, ir reflectance and optical absor

  26. Sang-Hoon Kim, Mukunda P. Das

    Divergence exponents of the first-order quantum correction of a two-dimensional hard-sphere Bose atoms are obtained by an effective field theory method. The first-order correction to the ground-state energy density with respect to the zeroth-order is given by $\cale_1/\cale_0 \sim |D-2|^{-\al}|\lnγ|^{-\al&#39;}$, where $D$ is the spatial dimension, and $γ$ i

  27. Takeo Hoshi

    This article is composed of two parts; In the first part (Sec. 1), the ultra-large-scale electronic structure theory is reviewed for (i) its fundamental numerical algorithm and (ii) its role in nano-material science. The second part (Sec. 2) is devoted to the mathematical foundation of the large-scale electronic structure theory and their numerical aspects.

  28. Giuseppe Borrelli

    We prove that if the bicanonical map of a minimal surface of general type S with p_{g}=q=1 and K^2=8 is non birational, then it is a double cover onto a rational surface. An application of this theorem is the complete classification of minimal surfaces of general type with p_{g}=q=1, K^2=8 and nonbirational bicanonical map.

  29. Conor Mancone, Ata Sarajedini

    Using archival imaging from the Wide Field Planetary Camera 2 aboard the Hubble Space Telescope, we investigate the stellar populations of the Local Group dwarf spheroidal Andromeda V - a companion satellite galaxy of M31. The color-magnitude diagram (CMD) extends from above the first ascent red giant branch (RGB) tip to approximately one magnitude below the

  30. Xavier P. Koenig, Lori E. Allen, Robert A. Gutermuth, Joseph L. Hora

    We present images and initial results from our extensive Spitzer Space Telescope imaging survey of the W5 H II region with the Infrared Array Camera (IRAC) and Multiband Imaging Photometer for Spitzer (MIPS). We detect dense clusters of stars, centered on the O stars: HD 18326, BD +60 586, HD 17505 and HD 17520. At 24 microns substantial extended emission is

  31. Jere H. Jenkins, Ephraim Fischbach, John B. Buncher, John T. Gruenwald

    Unexplained periodic fluctuations in the decay rates of Si-32 and Ra-226 have been reported by groups at Brookhaven National Laboratory (Si-32), and at the Physikalisch-Technische-Bundesandstalt in Germany (Ra-226). We show from an analysis of the raw data in these experiments that the observed fluctuations are strongly correlated in time, not only with each

  32. Robert L. Kurucz

    One Population III dud supernova produces enough oxygen to enable ten million solar masses of primordial gas to bind into M dwarfs. This is possible because radiation from other Population III stars implodes the mixture of oxygen ejecta and primordial gas into a globular cluster. Model atmosphere calculations for oxygen dwarfs show that water blocks most of

  33. J. Menezes

    We investigated domain wall networks as a possible candidate to explain the present accelerated expansion of the universe. We discuss various requirements that any stable lattice of frustrated walls must obey and propose a class of `ideal&#39; model (in terms of its potential to lead to network frustration). By using the results of the largest and most accur

  34. A. Yu. Khrennikov, V. M. Shelkovich

    We study the asymptotical behavior of the $p$-adic singular Fourier integrals $$ J_{π_α,m;ϕ}(t) =\bigl< f_{π_α;m}(x)χ_p(xt), ϕ(x)\bigr> =F\big[f_{π_α;m}ϕ\big](t), \quad |t|_p \to \infty, \quad t\in \bQ_p, $$ where $f_{π_α;m}\in {\cD}&#39;(\bQ_p)$ is a {\em quasi associated homogeneous} distribution (generalized function) of degree $π_α(x)=|x|_p^{α-1}π_1(x)$

  35. J. -Y. P. Delannoy, M. J. P. Gingras, P. C. W. Holdsworth, A. -M. S. Tremblay

    Spin-only descriptions of the half-filled one-band Hubbard model are relevant for a wide range of Mott insulators. In addition to the usual Heisenberg exchange, many new types of interactions, including ring exchange, appear in the effective Hamiltonian in the intermediate coupling regime. In order to improve on the quantitative description of magnetic excit

  36. Samy Merabia, Pawel Keblinski, Laurent Joly, Laurent Lewis

    We study heat transfer from a heated nanoparticle into surrounding fluid, using molecular dynamics simulations. We show that the fluid next to the nanoparticle can be heated well above its boiling point without a phase change. Under increasing nanoparticle temperature, the heat flux saturates which is in sharp contrast with the case of flat interfaces, where

  37. Morgan Sherman

    In a recent paper Donaldson defines three operators on a space of Hermitian metrics on a complex projective manifold: $T, T_ν, T_K.$ Iterations of these operators converge to balanced metrics, and these themselves approximate constant scalar curvature metrics. In this paper we investigate the convergence properties of these iterations by examining the case o

  38. Shamgar Gurevich, Ronny Hadani

    The discrete Fourier transform (DFT) is an important operator which acts on the Hilbert space of complex valued functions on the ring Z/NZ. In the case where N=p is an odd prime number, we exhibit a canonical basis of eigenvectors for the DFT. The transition matrix from the standard basis to the canonical basis defines a novel transform which we call the dis

  39. F. Bello, D. M. Whittaker

    Our model comprehensively simulates modern nanoscale semiconductor microcavities incorporating cavity quantum electrodynamics within both the weak and strong coupling regimes, using on-resonant laser excitation and nonresonant excitation due to a wetting layer. For weak coupling, the most significant effect is photon antibunching with nonresonant emission. W

  40. J. I. Katz

    A basketball bounced on a stiff surface produces a characteristic loud thump, followed by high-pitched ringing. Describing the ball as an inextensible but flexible membrane containing compressed air, I formulate an approximate theory of the generation of these sounds and predict their amplitudes and waveforms.

  41. Lu-Xin Liu

    The local conformal symmetry is spontaneously broken down to the Local Lorentz invariance symmetry through the approach of nonlinear realization. The resulting effective Lagrangian, in the unitary gauge, describes a cosmological vector field non-minimally coupling to the gravitational field. As a result of the Higgs mechanism, the vector field absorbs the di

  42. Andrew N. Norris

    Acoustic metafluids are defined as the class of fluids that allow one domain of fluid to acoustically mimic another, as exemplified by acoustic cloaks. It is shown that the most general class of acoustic metafluids are materials with anisotropic inertia and the elastic properties of what are known as pentamode materials. The derivation uses the notion of fin

  43. S. Mieske, J. Dabringhausen, P. Kroupa, M. Hilker

    Various studies have established that the dynamical M/L ratios of ultra-compact dwarf galaxies (UCDs) tend to be at the limit or beyond the range explicable by standard stellar populations with canonical IMF. We discuss how IMF variations may account for these high M/L ratios and how observational approaches may in the future allow to discriminate between th

  44. Edward Belbruno, Amaya Moro-Martin, Renu Malhotra

    The exchange of meteorites among the terrestrial planets of our Solar System is a well established phenomenon that has triggered discussion of lithopanspermia within the Solar System. Similarly, could solid material be transferred across planetary systems? To address this question, we explore the dynamics of the transfer of small bodies between planetary sys

  45. Cristiana Bertolin

    Let k be a separably closed field. Let K_i=[A_i \to B_i] (for i=1,2,3) be three 1-motives defined over k. We define the geometrical notions of extension of K_1 by K_3 and of biextension of (K_1,K_2) by K_3. We then compute the homological interpretation of these new geometrical notions: namely, the group Biext^0(K_1,K_2;K_3) of automorphisms of any biextensi

  46. Dragos Ghioca, Thomas J. Tucker

    We prove a dynamical version of the Bogomolov conjecture in the special case of lines in affine space A^m under the action of a map (f_1,...,f_m) where each f_i is a polynomial in Q-bar[X] of the same degree.

  47. Piotr T. Chruściel, Gregory J. Galloway, Didier Solis

    The standard topological censorship theorems require asymptotic hypotheses which are too restrictive for several situations of interest. In this paper we prove a version of topological censorship under significantly weaker conditions, compatible e.g. with solutions with Kaluza-Klein asymptotic behavior. In particular we prove simple connectedness of the quot

  48. Abhishek Dhar

    Recent results on theoretical studies of heat conduction in low-dimensional systems are presented. These studies are on simple, yet nontrivial, models. Most of these are classical systems, but some quantum-mechanical work is also reported. Much of the work has been on lattice models corresponding to phononic systems, and some on hard particle and hard disc s

  49. Y. K. Li, X. Lin, Z. W. Zhu, H. Chen

    We investigate superconductivity and transport properties of Co doped SmFe$_{1-x}$Co$_{x}$AsO system. The antiferromagnetic (AFM) spin-density wave (SDW) order is rapidly suppressed by Co doping, and superconductivity emerges as $x$ $\geq$ 0.05. $T_c$$^{mid}$ increases with increasing Co content, shows a maximum of 17.2 K at the optimally doping of $x\sim$ 0

  50. George Douzas, Theodoros Grammatikopoulos, George Zoupanos

    We consider a N=1 supersymmetric E(8) gauge theory, defined in ten dimensions and we determine all four-dimensional gauge theories resulting from the generalized dimensional reduction a la Forgacs-Manton over coset spaces, followed by a subsequent application of the Wilson flux spontaneous symmetry breaking mechanism. Our investigation is constrained only by

  51. Martin Cederwall

    We reformulate the Bagger-Lambert-Gustavsson model using an N=8 superspace, thus making the full supersymmetry manifest. The formulation is based on appropriate "pure spinor wave functions" for the Chern-Simons and matter multiplets. The Lagrangian has an extremely simple structure, essentially containing a Chern-Simons-like term for the gauge field wave fun

  52. Giuliano Benenti, Giulio Casati

    In classical mechanics the complexity of a dynamical system is characterized by the rate of local exponential instability which effaces the memory of initial conditions and leads to practical irreversibility. In striking contrast, quantum mechanics appears to exhibit strong memory of the initial state. Here we introduce a notion of complexity for a quantum s

  53. Enrico Santamato

    A rigorous \textit{ab initio} derivation of the (square of) Dirac&#39;s equation for a single particle with spin is presented. The general Hamilton-Jacobi equation for the particle expressed in terms of a background Weyl&#39;s conformal geometry is found to be linearized, exactly and in closed form, by an \textit{ansatz} solution that can be straightforwardl

  54. Wei-Qiang Chen, Kai-Yu Yang, Yi Zhou, Fu-Chun Zhang

    Superconductivity in iron pnictides is studied by using a two-orbital Hubbard model in the large U limit. The Coulomb repulsion induces an orbital-dependent pairing between charge carriers. The pairing is found mainly from the scattering within the same Fermi pocket. The inter-pocket pair scatterings determine the symmetry of the superconductivity, which is

  55. Shesansu Pal

    In this short note, we have generalized and constructed gravity solutions with two &#34;exponents&#34; {\it a la} Kachru, Liu and Mulligan. The coordinate system that is used to construct the gravity solution is useful when $b$ vanishes. It means we can describe the theory having only the temporal scale invariance apart from the combination of both temporal

  56. Zhi-Hua Zhou, Min-Ling Zhang, Sheng-Jun Huang, Yu-Feng Li

    In this paper, we propose the MIML (Multi-Instance Multi-Label learning) framework where an example is described by multiple instances and associated with multiple class labels. Compared to traditional learning frameworks, the MIML framework is more convenient and natural for representing complicated objects which have multiple semantic meanings. To learn fr

  57. Jerrald Meek

    This is the final article in a series of four articles. Richard Karp has proven that a deterministic polynomial time solution to K-SAT will result in a deterministic polynomial time solution to all NP-Complete problems. However, it is demonstrated that a deterministic polynomial time solution to any NP-Complete problem does not necessarily produce a determin

  58. Chris Wendl

    We show that every open book decomposition of a contact 3-manifold can be represented (up to isotopy) by a smooth R-invariant family of pseudoholomorphic curves on its symplectization with respect to a suitable stable Hamiltonian structure. In the planar case, this family survives small perturbations, and thus gives a concrete construction of a stable finite

  59. Viktor G. Kravchenko, Vladislav V. Kravchenko, Sébastien Tremblay

    In [1] a hyperbolic analogue of pseudoanalytic function theory was developed. In the present contribution we show that one of the central objects of the inverse problem method the Zakharov-Shabat system is closely related to a hyperbolic Vekua equation for which among other results a generating sequence and hence a complete system of formal powers can be con

  60. H. Wang, M. Hofheinz, M. Ansmann, R. C. Bialczak

    We demonstrate the controlled generation of Fock states with up to 15 photons in a microwave coplanar waveguide resonator coupled to a superconducting phase qubit. The subsequent decay of the Fock states, due to dissipation, is then monitored by varying the time delay between preparing the state and performing a number-state analysis. We find that the decay

  61. Alexander S. Balankin, Didier Samayoa Ochoa, Ernesto Pineda Leon, Rolando Cortes Montes de Oca

    We study the lateral deformations of randomly folded elastoplastic and predominantly plastic thin sheets under the uniaxial and radial compressions. We found that the lateral deformations of cylinders folded from elastoplastic sheets of paper obey a power law behavior with the universal Poissons index nu = 0.17 pm 0.01, which does not depend neither the pape

  62. Alexander S. Balankin, Orlando Susarrey Huerta

    We have studied experimentally and theoretically the response of randomly folded hyperelastic and elastoplastic sheets on the uniaxial compression loading and the statistical properties of crumpling networks. The results of these studies reveal that the mechanical behavior of randomly folded sheets in the one-dimensional stress state is governed by the shape

  63. J. M. G. Vilar, J. M. Rubi

    We show that Peliti&#39;s Comment [arXiv:0808.2855] fails to appreciate basic physical principles and consequently misrepresents both our work as well as the classical work of Gibbs and Tolman.

  64. J. M. G. Vilar, J. M. Rubi

    We show that the Comment [arXiv:0808.1224] by Horowitz and Jarzynski obtains as a main result a general free energy change for a harmonic system that in the macroscopic limit does not recover the textbook expression for the energy change of a Hookean spring. The reason is that Horowitz and Jarzynski improperly identify work with parametric changes of the Ham

  65. Taehyun Kim, Franco N. C. Wong

    Entanglement distillation is a procedure for extracting from one or more pairs of entangled qubits a smaller number of pairs with a higher degree of entanglement that is essential for many applications in quantum information science. Schmidt projection is a unique distillation method that can be applied to more than two pairs of entangled qubits at the same

  66. Alexander S. Balankin

    We propose a new approach for properly analyzing stochastic time series by mapping the dynamics of time series fluctuations onto a suitable nonequilibrium surface-growth problem. In this framework, the fluctuation sampling time interval plays the role of time variable, whereas the physical time is treated as the analog of spatial variable. In this way we fou

  67. Jason Bell, Dragos Ghioca, Thomas J. Tucker

    We prove a dynamical version of the Mordell-Lang conjecture for etale endomorphisms of quasiprojective varieties. We use p-adic methods inspired by the work of Skolem, Mahler, and Lech, combined with methods from algebraic geometry. As special cases of our result we obtain a new proof of the classical Mordell-Lang conjecture for cyclic subgroups of a semiabe

  68. Ajay C. Ramadoss

    This short note proves a generalization of the Hirzebruch Riemann-Roch theorem equivalent to the Cardy condition described in [1]. This is done using an earlier result [4] that explicitly describes what the Mukai pairing in [1] descends to in Hodge cohomology via the Hochschild-Kostant-Rosenberg map twisted by the root Todd genus.

  69. Anatoliy P. Petravchuk

    Let $L$ be a finite dimensional Lie algebra over a field $F$. It is well known that the solvable radical $S(L)$ of the algebra $L$ is a characteristic ideal of $L$ if $\char F=0$ and there are counterexamples to this statement in case $\char F=p>0$. We prove that the sum $S(L)$ of all solvable ideals of a Lie algebra $L$ (not necessarily finite dimensional)

  70. L. -X. Zhang, D. V. Melnikov, J. -P. Leburton

    We study the properties of a few-electron system confined in coupled elongated quantum dots (QDs) using a model Gaussian potential and the numerical exact diagonalization technique. In the absence of magnetic fields, as the aspect ratio $r$ between the QD extensions in the direction perpendicular and parallel to the coupling directions increases, the exchang

  71. Indranil Biswas, Georg Schumacher

    We investigate differential geometric aspects of moduli spaces parametrizing solutions of coupled vortex equations over a compact Kaehler manifold X. These solutions are known to be related to polystable triples via a Kobayashi-Hitchin type correspondence. Using a characterization of infinitesimal deformations in terms of the cohomology of a certain elliptic

  72. Tony J. Puthenpurakal

    Let $(A,\m)$ be a Noetherian local ring, let $M$ be a finitely generated \CM $A$-module of dimension $r \geq 2$ and let $I$ be an ideal of definition for $M$. Set $L^I(M) = \bigoplus_{n\geq 0}M/I^{n+1}M$. In part one of this paper we showed that $L^I(M)$ is a module over $\R$, the Rees algebra of $I$ and we gave many applications of $L^I(M)$ to study the ass

  73. M. Liguori, A. Riotto

    We study the impact of cosmological parameters&#39; uncertainties on estimates of the primordial NG parameter f_NL in local and equilateral models of non-Gaussianity. We show that propagating these errors increases the f_NL relative uncertainty by 16% for WMAP and 5 % for Planck in the local case, whereas for equilateral configurations the correction term ar

  74. Sylvain Brochard

    This text is my thesis, defended in June 2007, in the status it was at this time. The most important results are contained in the article &#34;Foncteur de Picard d&#39;un champ algébrique&#34; to appear in &#34;Mathematische Annalen&#34; (see the preprint arXiv:0711.4545). In the article, some results have been added, and some previous results have been stre

  75. Junfeng Dai, Jun Li, Hualing Zeng, Xiaodong Cui

    We report a measurement on quantum capacitance of individual semiconducting and small band gap SWNTs. The observed quantum capacitance is remarkably smaller than that originating from density of states and it implies a strong electron correlation in SWNTs.

  76. Kazumasa Hattori, Hirokazu Tsunetsugu

    We investigate heavy fermion behaviors in the vanadium spinel LiV_2O_4. We start from a three-orbital Hubbard model on the pyrochlore lattice and derive its low-energy effective Hamiltonian by an approach of real-space renormalization group type. One important tetrahedron configuration in the rochlore lattice has a three-fold orbital degeneracy and spin S=1,

  77. Jeff Cheeger, Bruce Kleiner

    We prove the differentiability of Lipschitz maps X-->V, where X is a complete metric measure space satisfying a doubling condition and a Poincaré inequality, and V is a Banach space with the Radon Nikodym Property (RNP). The proof depends on a new characterization of the differentiable structure on such metric measure spaces, in terms of directional derivati

  78. E. Ostrovsky

    We prove in this article that every Borelian measure, for example, the distribution of a random variable, in separable Banach space has a support which is compact embedded Banach subspace; and prove that if the norm of the random variable belongs to some exponential Orlicz space, then the new subspace can be choose such that the norm of this variable in the

  79. E. Ostrovsky, E. Rogover

    In this paper non-asymptotic exact rearrangement invariant norm estimates are derived for the maximum distribution of the family elements of some rearrangement invariant (r.i.) space over unbounded measure in the entropy terms and in the terms of generic chaining. We consider some applications in the martingale theory and in the theory of Fourier series.

  80. G. Holzegel

    In this paper we prove the non-linear asymptotic stability of the five-dimensional Schwarzschild metric under biaxial vacuum perturbations. This is the statement that the evolution of (SU(2) x U(1))-symmetric vacuum perturbations of initial data for the five-dimensional Schwarzschild metric finally converges in a suitable sense to a member of the Schwarzschi

  81. Minh-Tien Tran

    The Keldysh boundary problem in a nonequilibrium Falicov-Kimball model in infinite dimensions is studied within the truncated and self-consistent perturbation theories, and the dynamical mean-field theory. Within the model the system is started in equilibrium, and later a uniform electric field is turned on. The Kadanoff-Baym-Wagner equations for the nonequi

  82. Yulia Kempner, Vadim E. Levit

    A function $F$ defined on all subsets of a finite ground set $E$ is quasi-concave if $F(X\cup Y)\geq\min\{F(X),F(Y)\}$ for all $X,Y\subset E$. Quasi-concave functions arise in many fields of mathematics and computer science such as social choice, theory of graph, data mining, clustering and other fields. The maximization of quasi-concave function takes, in g

  83. Vesna Manojlovic

    This thesis consists of Chapters 1 and 2. The main results are contained in the two preprints and two published papers, listed below. Chapter 1 deals with conformal invariants in the euclidean space Rn; n >= 2; and their interrelation. In particular, conformally invariant metrics and balls of the respective metric spaces are studied. Another theme in Chapter

  84. Kamal K. Nandi, Ilnur Nigmatzyanov, Ramil Izmailov, Nail G. Migranov

    The present paper reports interesting new features that wormhole solutions in the scalar field gravity theory have. To demonstrate these, we obtain, by using a slightly modified form of the Matos-Nunez algorithm, an extended class of asymptotically flat wormhole solutions belonging to Einstein minimally coupled scalar field theory. Generally, solutions in th

  85. A. Palit, A. Panchenko, N. G. Migranov, A. Bhadra

    Phase space method provides a novel way for deducing qualitative features of nonlinear differential equations without actually solving them. The method is applied here for analyzing stability of circular orbits of test particles in various physically interesting environments. The approach is shown to work in a revealing way in Schwarzschild spacetime. All re

  86. Kei Funano

    In this paper, we study the Lévy-Milman concentration phenomenon of 1-Lipschitz maps into infinite dimensional metric spaces. Our main theorem asserts that the concentration to an infinite dimensional $\ell^p$-ball with the $\ell^q$-distance function for $1\leq p<q\leq +\infty$ is equivalent to the concentration to the real line.

  87. Indranil Biswas, Mainak Poddar

    Let X be a compact connected Riemann surface of genus at least two. We compute the Chen--Ruan cohomology ring of the moduli space of stable PSL(2, C)--bundles of nontrivial second Stiefel--Whitney class over X.

  88. Jialing Liu, Vikas Yadav, Hullas Sehgal, Joshua M. Olson

    In this paper, we study the phase transition behavior emerging from the interactions among multiple agents in the presence of noise. We propose a simple discrete-time model in which a group of non-mobile agents form either a fixed connected graph or a random graph process, and each agent, taking bipolar value either +1 or -1, updates its value according to i

  89. Andrew R. Missel Karin A. Dahmen

    We investigate transport in a disordered reaction-diffusion (RD) model consisting of particles which are allowed to diffuse, compete with one another (2A->A), give birth in small areas called &#34;oases&#34; (A->2A), and die in the &#34;desert&#34; outside the oases (A->0). This model has previously been used to study bacterial populations in the lab and is

  90. Carl H. Gibson, Rudolph E. Schild

    Self-gravitational fluid mechanical methods termed hydro-gravitational-dynamics (HGD) predict plasma fragmentation 0.03 Myr after the turbulent big bang to form protosuperclustervoids, turbulent protosuperclusters, and protogalaxies at the 0.3 Myr transition from plasma to gas. Linear protogalaxyclusters fragment at 0.003 Mpc viscous-inertial scales along tu

  91. Harry P. Warren, Ignacio Ugarte-Urra, George A. Doschek, David H. Brooks

    Previous solar observations have shown that coronal loops near 1 MK are difficult to reconcile with simple heating models. These loops have lifetimes that are long relative to a radiative cooling time, suggesting quasi-steady heating. The electron densities in these loops, however, are too high to be consistent with thermodynamic equilibrium. Models proposed

  92. Yong Zhang, Sun Kwok, Dinh-V-Trung

    We present a spectral line survey of the C-rich envelope CIT 6 in the 2mm and 1.3mm bands carried out with the Arizona Radio Observatory (ARO) 12m telescope and the Heinrich Hertz Submillimeter Telescope (SMT). The observations cover the frequency ranges of 131--160 GHz, 219--244 GHz, and 252--268 GHz with typical sensitivity limit of T_R<10 mK. A total of 7

  93. Joerg Winkelmann

    We compare the behaviour of entire curves and integral sets, in particular in relation to locally trivial fiber bundles, algebraic groups and finite ramified covers over semi-abelian varieties.

  94. David Jewitt, Amaya Moro-Martín, Pedro Lacerda

    We discuss the current knowledge of the Solar system, focusing on bodies in the outer regions, on the information they provide concerning Solar system formation, and on the possible relationships that may exist between our system and the debris disks of other stars. Beyond the domains of the Terrestrial and giant planets, the comets in the Kuiper belt and th

  95. C. O. Dorso, C. M. Hernández, J. A. López, J. A. Muñoz

    This study shows that isoscaling, usually studied in nuclear reactions, is a phenomenon common to all cases of fair sampling. Exact expressions for the yield ratio $R_{21}$ and approximate expressions for the isoscaling parameters $α$ and $β$ are obtained and compared to experimental results. It is concluded that nuclear isoscaling is bound to contain a comp

  96. D. A. Kann

    The precise localization of short/hard (Type I) gamma-ray bursts (GRBs) in recent years has answered many questions but raised even more. I present some results of a systematic study of the optical afterglows of long/soft (Type II) and short/hard (Type I) GRBs, focusing on the optical luminosity as another puzzle piece in the classification of GRBs.

  97. A. Tartaglia

    The presence of defects in material continua is known to produce internal permanent strained states. Extending the theory of defects to four dimensions and allowing for the appropriate signature, it is possible to apply these concepts to space-time. In this case a defect would induce a non-trivial metric tensor, which can be interpreted as a gravitational fi

  98. Ming-Zhe Chen

    This paper presents a mistake in work function algorithm of k-server conjecture. That is, the monotonicity of the work function is not always true.

  99. Claudia Fassino

    Let X be a set of s points whose coordinates are known with only limited From the numerical point of view, given a set X of s real points whose coordinates are known with only limited precision, each set X* of real points whose elements differ from those of X of a quantity less than the data uncertainty can be considered equivalent to X. We present an algori

  100. Misha Verbitsky

    A manifold (M,I,J,K) is called hypercomplex if I,J,K are complex structures satisfying quaternionic relations. A quaternionic Hermitian metric is called HKT (hyperkaehler with torsion) if $Idω_I = Jd ω_J=Kdω_K$, where $ω_I,ω_J, ω_K$ are Hermitian forms associated with I, J, K. A Hermitian metric $ω$ on a complex manifold is called balanced if $d^*ω=0$. We sh