October 2006 arXiv papers

Clifford Henry Taubes

Let M denote a compact, oriented 3-manifold and let a denote a contact 1-form on M. This article proves that the vector field that generates the kernel of the 2-form da has at least one closed, integral curve.

Ben Kilminster

We present CDF and D0 searches for a Standard Model Higgs boson produced associatively with a W or Z boson at sqrt{s}=1.96 TeV using up to 1 fb^-1 of analyzed Tevatron data collected from February 2002 to February 2006. For Higgs masses less than 135 GeV/c^2, as is favored by experimental and theoretical constraints, WH->lnubb, ZH->llbb, and ZH->nunubb are t

Lu Zhou, Weiping Zhang, Hong Y. Ling, Lei Jiang

We study the coherent association of a two-species atomic condensate into a condensate of heteronuclear diatomic molecules, using both a semiclassical treatment and a quantum mechanical approach. The differences and connections between the two approaches are examined. We show that, in this coupled nonlinear atom-molecule system, the population difference bet

Dan Guralnik

In this work we introduce a new combinatorial notion of boundary $\Re C$ of an $ω$-dimensional cubing $C$. $\Re C$ is defined to be the set of almost-equality classes of ultrafilters on the standard system of halfspaces of $C$, endowed with an order relation reflecting the interaction between the Tychonoff closures of the classes. When $C$ arises as the dual

Daniel Green

Recent work on closed string tachyon condensation suggests the existence of a `nothing state' where closed strings and space itself vanish. We consider the evolution of D-branes in such backgrounds, focusing on the early stages of the condensation process. We find evidence that the branes exist in the region; although, generically their apparent mass gro

Joshua J. Friess, Steven S. Gubser, Georgios Michalogiorgakis, Silviu S. Pufu

We compute the gravitational quasinormal modes of the global AdS_5-Schwarzschild solution. We show how to use the holographic dual of these modes to describe a thermal plasma of finite extent expanding in a slightly anisotropic fashion. We compare these flows with the behavior of quark-gluon plasmas produced in relativistic heavy ion collisions by estimating

Gabriel Katz

We notice that a generic nonsingular gradient field $v = \nabla f$ on a compact 3-fold $X$ with boundary canonically generates a simple spine $K(f, v)$ of $X$. We study the transformations of $K(f, v)$ that are induced by deformations of the data $(f, v)$. We link the Matveev complexity $c(X)$ of $X$ with counting the \emph{double-tangent} trajectories of th

A. Dranishnikov, S. Ferry, S. Weinberger

We show that there are homotopy equivalences $h:N\to M$ between closed manifolds which are induced by cell-like maps $p:N\to X$ and $q:M\to X$ but which are not homotopic to homeomorphisms. The phenomenon is based on construction of cell-like maps that kill certain $\mathbb L$-classes. The image space in these constructions is necessarily infinite-dimensiona

Takao Kotani, Mark van Schilfgaarde, Sergey V. Faleev

We have developed a new type of self-consistent scheme within the $GW$ approximation, which we call quasiparticle self-consistent $GW$ (QS$GW$). We have shown that QS$GW$ rather well describes energy bands for a wide-range of materials, including many where the local-density approximation fails. QS$GW$ contains physical effects found in other theories such a

J. A. Hoyos, Thomas Vojta

We investigate a single defect coupling to the square of the order parameter in a nearly critical magnet with long-range spatial interactions of the form $r^{-(d+σ)}$, focusing on magnetic droplets nucleated at the defect while the bulk system is in the paramagnetic phase. Because of the long-range interaction, the droplet develops a power-law tail which is

J. A. S. Lima, J. V. Cunha, J. S. Alcaniz

We propose a new class of accelerating world models unifying the cosmological dark sector (dark matter and dark energy). All the models are described by a simplified version of the Chaplygin gas Quartessence cosmology. It is found that even for $Ω_k \neq 0$, this Quartessence scenario depends only on a pair of parameters which can severely be constrained by

Geoffrey T. Bodwin, Daekyoung Kang, Taewon Kim, Jungil Lee

We compute relativistic corrections to the process $e^+e^- \to J/ψ+ η_c$ and find that they resolve the discrepancy between theory and experiment.

Martin Kunz, Bruce A. Bassett, Renee Hlozek

Observed data is often contaminated by undiscovered interlopers, leading to biased parameter estimation. Here we present BEAMS (Bayesian Estimation Applied to Multiple Species) which significantly improves on the standard maximum likelihood approach in the case where the probability for each data point being `pure' is known. We discuss the application of

Mark R. Krumholz, Richard I. Klein, Christopher F. McKee, John Bolstad

We analyze the mixed frame equations of radiation hydrodynamics under the approximations of flux-limited diffusion and a thermal radiation field, and derive the minimal set of evolution equations that includes all terms that are of leading order in any regime of non-relativistic radiation hydrodynamics. Our equations are accurate to first order in v/c in the

Romain Tessera

We prove that the first reduced cohomology with values in a mixing Lp-representation, p larger than 1, vanishes for a class of amenable groups including connected amenable Lie groups. In particular this solves for this class of amenable groups a conjecture of Gromov saying that every finitely generated amenable group has no first reduced lp-cohomology. As a

D. Gross, K. Audenaert, J. Eisert

We clarify the mathematical structure underlying unitary $t$-designs. These are sets of unitary matrices, evenly distributed in the sense that the average of any $t$-th order polynomial over the design equals the average over the entire unitary group. We present a simple necessary and sufficient criterion for deciding if a set of matrices constitutes a desig

Tesla E. Jeltema, John S. Mulchaey, Lori M. Lubin, Christopher D. Fassnacht

We investigate the galaxy populations in seven X-ray selected, intermediate-redshift groups (0.2<z<0.6). Overall, the galaxy populations in these systems are similar to those in clusters at the same redshift; they have large fractions of early-type galaxies (f_e~70%) and small fractions of galaxies with significant star formation (f_[OII]~30%). We do not obs

Anirban Basu

The modular invariant coefficient of the D^{2k} {\cal{R}}^4 term in the effective action of type IIB superstring theory is expected to satisfy Poisson equation on the fundamental domain of SL(2,Z). Under certain assumptions, we obtain the equation satisfied by D^{10} {\cal{R}}^4 using the tree level and one loop results for four graviton scattering in type I

Maria Jose Cantero, Barry Simon

For the standard symplectic forms on Jacobi and CMV matrices, we compute Poisson brackets of OPRL and OPUC, and relate these to other basic Poisson brackets and to Jacobians of basic changes of variable.

Vladimir Kanovei

We present a selection of basic results on Borel reducibility of Borel ideals and equivalence relations, especially those with comparably short proofs. The focal point are reducibility/irreducibility results related to some special equivalences like $E_0, E_1, E_2, E_3, E_\infty, Z_0,$ and Banach-induced equivalences $l_p,$ in particular several dichotomy th

Kenji Fukushima, Francois Gelis, Larry McLerran

The Color Glass Condensate (CGC) predicts the form of the nuclear wavefunction in QCD at very small x. Using this, we compute the wavefunction for the collision of two nuclei, infinitesimally in the forward light cone. We show that the Wigner transformation of this wavefunction generates rapidity dependent fluctuations around the boost invariant classical so

Ruth Charney, John Crisp, Karen Vogtmann

We study the outer automorphism group of a right-angled Artin group A_G in the case where the defining graph G is connected and triangle-free. We give an algebraic description of Out(A_G) in terms of maximal join subgraphs in G and prove that the Tits&#39; alternative holds for Out(A_G). We construct an analogue of outer space for Out(A_G) and prove that it

Pavel Mnev

In this work we discuss the construction of &#34;simplicial BF theory&#34;, the field theory with finite-dimensional space of fields, associated to a triangulated manifold, that is in a sense equivalent to topological BF theory on the manifold (with infinite-dimensional space of fields). This is done in framework of simplicial program - program of constructi

Jordi Lopez Abad

We give a list of canonical equivalence relations on discrete nets of the positive unit sphere of $c_0$. This generalizes results of W. T. Gowers and A. D. Taylor.

Joël Merker, Egmont Porten

100 years ago exactly, in 1906, Hartogs published a celebrated extension phenomenon (birth of Several Complex Variables), whose global counterpart was stated in full generality later by Osgood (1929): holomorphic functions in a connected neighborhood V(bD) of a connected boundary bD contained in C^n (n >= 2) do extend holomorphically and uniquely to the doma

Ivone F. M. Albuquerque, Sergio Palomares-Ruiz, Tom Weiler

This working group focused mainly on the complementarity among particle physics and astrophysics. The analysis of data from both fields will better constrain theoretical models. Much of the discussion focused on detecting dark matter and susy particles, and on the potential of neutrino and gamma-ray astrophysics for seeking or constraining new physics.

Louis Leblond, Sarah Shandera

In certain implementations of the brane inflationary paradigm, the exit from inflation occurs when the branes annihilate through tachyon condensation. We investigate various cosmological effects produced by this tachyonic era. We find that only a very small region of the parameter space (corresponding to slow-roll with tiny inflaton mass) allows for the tach

Steven A. Abel, Chong-Sun Chu, Joerg Jaeckel, Valentin V. Khoze

Supersymmetry breaking in a metastable vacuum is re-examined in a cosmological context. It is shown that thermal effects generically drive the Universe to the metastable minimum even if it begins in the supersymmetry-preserving one. This is a generic feature of the ISS models of metastable supersymmetry breaking due to the fact that SUSY preserving vacua con

Alexey Boyarsky, Jukka Nevalainen, Oleg Ruchayskiy

We improve the earlier restrictions on parameters of the dark matter (DM) in the form of a sterile neutrino. The results were obtained from non-observing the DM decay line in the X-ray spectrum of the Milky Way (using the recent XMM-Newton PN blank sky data). We also present a similar constraint coming from the recent XMM-Newton observation of Ursa Minor --

Francisco Jiménez-Esteban, Dieter Engels, Pedro García-Lario

We performed a near-IR/optical monitoring programme from 1999 to 2005 in order to study the variability properties of the &#39;Arecibo sample of OH/IR stars&#39; (periods, amplitudes, and colour variations). Here we describe this multi-wavelength long-term monitoring programme. Data analysis is still in process. Our ultimate goal is to study in particular th

Philipp Gerhold, Ernst-Michael Ilgenfritz, Michael Müller-Preussker

Two improved superposition schemes for the construction of approximate multi-caloron-anticaloron configurations, using exact single (anti)caloron gauge fields as underlying building blocks, are introduced in this paper. The first improvement deals with possible monopole-Dirac string interactions between different calorons with non-trivial holonomy. The secon

S. James Gates,, Sergei M. Kuzenko, Gabriele Tartaglino-Mazzucchelli

We present new off-shell formulations for the massive superspin-3/2 multiplet. In the massless limit, they reduce respectively to the old minimal (n=-1/3) and non-minimal ($n\neq -1/3, 0$) linearized formulations for 4D N=1 supergravity. Duality transformations, which relate the models constructed, are derived.

Nikolai Gordeev, Fritz Grunewald, Boris Kunyavskii, Eugene Plotkin

We are looking for the smallest integer k>1 providing the following characterization of the solvable radical R(G) of any finite group G: R(G) coincides with the collection of all g such that for any k elements a_1,a_2,...,a_k the subgroup generated by the elements g, a_iga_i^{-1}, i=1,...,k, is solvable. We consider a similar problem of finding the smallest

Kontogeorgis Aristides

We apply the known results on the Galois module structure of the sheaf of polydifferentials in order to study the dimension of the tangent space of the deformation functor of curves with automorphisms. We are able to find the dimension for the case of weakly ramified covers and for the case of the action of a cyclic group of order $p^v$.

Zhi-Wei Sun

Let G be any additive abelian group with cyclic torsion subgroup, and let A, B and C be finite subsets of G with cardinality n>0. We show that there is a numbering {a_i}_{i=1}^n of the elements of A, a numbering {b_i}_{i=1}^n of the elements of B and a numbering {c_i}_{i=1}^n of the elements of C, such that all the sums a_i+b_i+c_i (i=1,...,n) are distinct.

D. Fargion, P. Oliva

Recent homogeneous and isotropic maps of UHECR, suggest an isotropic cosmic origin almost uncorrelated to nearby Local Universe prescribed by GZK (tens Mpc) cut-off. Z-Burst model based on UHE neutrino resonant scattering on light relic ones in nearby Hot neutrino Dark Halo, may overcome the absence of such a local imprint and explain the recent correlation

Horacio E. Castillo, Azita Parsaeian

The presence of dynamical heterogeneities, i.e. nanometer-scale regions containing molecules rearranging cooperatively at very different rates compared to the bulk, is increasingly being recognized as crucial in our understanding of the glass transition, from the non-exponential nature of relaxation, to the divergence of the relaxation times. Recently, dynam

C. Blume

The energy dependence of various hadronic observables is reviewed. The study of their evolution from AGS over SPS to the highest RHIC energy reveals interesting features, which might locate a possible onset of deconfinement. These observables include transverse spectra of different particle types and their total multiplicities, as well as elliptic flow. In t

P. J. Silva, O. Oliveira

We report on the infrared limit of the quenched lattice Landau gauge gluon propagator computed from large asymmetric lattices. In particular, the compatibility of the pure power law infrared solution $(q^2)^{2κ}$ of the Dyson-Schwinger equations is investigated and the exponent $κ$ is measured. Some results for the ghost propagator and for the running coupli

J. E. Duboscq

I present two analyses done with the CLEOIII detector at CESR. The first is a search for the Lepton Flavor Violating decay Upsilon to mu tau, with preliminary results, and the second constrains Lepton Universality in Upsilon to tau tau relative to Upsilon to mu mu. This second analysis, whose results are final, has dramatically improved uncertainties relativ

Iduru Shigeta, Yukio Tanaka, Fusao Ichikawa, Yasuhiro Asano

We propose a new approach of smearing origins of a zero-bias conductance peak (ZBCP) in high-Tc superconductor tunnel junctions through the analysis based on the circuit theory for a d-wave pairing symmetry. The circuit theory has been recently developed from conventional superconductors to unconventional superconductors. The ZBCP frequently appears in line

G. Chiaselotti, G. Infante, G. Marino

In 1998 Manickam and Singhi conjectured that for every positive integer $d$ and every $n \ge 4d$, every set of $n$ real numbers whose sum is nonnegative contains at least $\binom {n-1}{d-1}$ subsets of size $d$ whose sums are nonnegative. In this paper we establish new results related to this conjecture. We also prove that the conjecture of Manickam and Sing

Javier López Peña

Motivated by some results in classical differential geometry, we give a constructive procedure for building up a connection over a (twisted) tensor product of two algebras, starting from connections defined on the factors. The curvature for the product connection is explicitly calculated, and shown to be independent of the choice of the twisting map and the

Henryk Fuks

We investigate critical properties of a class of number-conserving cellular automata (CA) which can be interpreted as deterministic models of traffic flow with anticipatory driving. These rules are among the only known CA rules for which the shape of the fundamental diagram has been rigorously derived. In addition, their fundamental diagrams contain nonlinea

Mohsen Bahramgiri, Salman Beigi

Graph states are well-entangled quantum states that are defined based on a graph. Of course, if two graphs are isomorphic their associated states are the same. Also, we know local operations do not change the entanglement of quantum states. Therefore, graph states that are either isomorphic or equivalent under the local Clifford group have the same propertie

Cheuk-Yin Wong, Horace W. Crater

We compare current-current correlators in lattice gauge calculations with correlators in different potential models, for a pseudoscalar charmonium in the quark-gluon plasma. An important ingredient in the evaluation of the current-current correlator in the potential model is the basic principle that out of the set of continuum states, only resonance states a

Lucas Fernández-Seivane, Jaime Ferrer

We analyze the impact of the magnetic anisotropy on the geometric structure and magnetic ordering of small atomic clusters of palladium, iridium, platinum and gold, using Density Functional Theory. Our results highlight the absolute need to include self-consistently the spin orbit interaction in any simulation of the magnetic properties of small atomic clust

Hai-Jun Yang, Byron P. Roe, Ji Zhu

In this paper, we compare the performance, stability and robustness of Artificial Neural Networks (ANN) and Boosted Decision Trees (BDT) using MiniBooNE Monte Carlo samples. These methods attempt to classify events given a number of identification variables. The BDT algorithm has been discussed by us in previous publications. Testing is done in this paper by

H. Itoyama, T. Oota

The kappa-symmetry-fixed Green-Schwarz action in the AdS_5 x S^5 background is treated canonically in a version of the light-cone gauge. After reviewing the generalized light-cone gauge for a bosonic sigma model, we present the Hamiltonian dynamics of the Green-Schwarz action by using the transverse degrees of freedom. The remaining fermionic constraints are

David Harvey

We show that the linear dependence on $p$ of the running time of Kedlaya&#39;s point-counting algorithm in characteristic $p$ may be reduced to $p^{1/2}$.

Tim Heaton-Burgess, Felipe A. Bulat, Weitao Yang

The finite basis optimized effective potential (OEP) method within density functional theory is examined as an ill-posed problem. It is shown that the generation of nonphysical potentials is a controllable manifestation of the use of unbalanced, and thus unsuitable, basis sets. A modified functional incorporating a regularizing smoothness measure of the OEP

Fei Wu, Ren-Xin Xu, Bo-Qiang Ma

A new model for the description of the behaviour of strangelets in the Earth&#39;s atmosphere is presented. Strangelet fission induced by collision with air nuclei is included. It is shown that strangelets with certain parameters of initial mass and energy may reach depths near sea level, which can be examined by ground-based experiments.

Zhi-Hui Guo, L. Y. Xiao, H. Q. Zheng

O(N) linear $σ$ model is solvable in the large $N$ limit and hence provides a useful theoretical laboratory to test various unitarization approximations. We find that the large $N_c$ limit and the $m_σ\to \infty$ limit do not commute. In order to get the correct large $N_c$ spectrum one has to firstly take the large $N_c$ limit. We argue that the $f_0(600)$

A. Mangiarotti, M. I. Lopes, M. L. Benabderrahmane, V. Chepel

The original Lindhard-Scharff-Schiøtt (LSS) theory and the more recent Tilinin theory for calculating the nuclear and electronic stopping powers of slow heavy ions are compared with predictions from the SRIM code by Ziegler. While little discrepancies are present for the nuclear contribution to the energy loss, large differences are found in the electronic o

George H. Hitching

Let E and F be vector bundles over a complex projective smooth curve X, and suppose that 0 -> E -> W -> F -> 0 is a nontrivial extension. Let G be a subbundle of F, and D an effective divisor on X. We give a criterion for the subsheaf G(-D) \subset F to lift to W, in terms of the geometry of a scroll in the extension space \PP H^1 (X, Hom(F, E)). We use this

Roland Queme

Let p be an odd prime. Let F_p^* be the no-null part of the finite field of p elements. Let K = Q(zeta) be the p-cyclotomic field and let O_K be the ring of integers of K. Let pi be the prime ideal of K lying over p. An integer B \in O_K is said singular if B^{1/p} not \in K and if B O_K = b^p where b is an ideal of O_K. An integer B \in O_K is said semi-pri

Stephen C. Anco

A bi-Hamiltonian hierarchy of complex vector soliton equations is derived from geometric flows of non-stretching curves in the Lie groups $G=SO(N+1),SU(N)\subset U(N)$, generalizing previous work on integrable curve flows in Riemannian symmetric spaces $G/SO(N)$. The derivation uses a parallel frame and connection along the curves, involving the Klein geomet

Ralph Blumenhagen, Boris Kors, Dieter Lust, Stephan Stieberger

This review article provides a pedagogical introduction into various classes of chiral string compactifications to four dimensions with D-branes and fluxes. The main concern is to provide all necessary technical tools to explicitly construct four-dimensional orientifold vacua, with the final aim to come as close as possible to the supersymmetric Standard Mod

Benjamin Lungwitz

The energy dependence of multiplicity fluctuations was studied for the most central Pb+Pb collisions at 20A, 30A, 40A, 80A and 158A GeV by the NA49 experiment at the CERN SPS. The multiplicity distribution for negatively and positively charged hadrons is significantly narrower than Poisson one for all energies. No significant structure in energy dependence o

A. V. Nefediev, J. E. F. T. Ribeiro, Adam P. Szczepaniak

The Goldberger--Treiman relation for heavy--light systems is derived in the context of a quark model. As a paradigmatic example, the case of ${\bar D}\to {\bar D}&#39; π$ is studied in detail. The fundamental role played by the pion two-component wave function, in the context of the Salpeter equation, is emphasized.

Francois Dahmani, Daniel Groves

We describe an algorithm which determines whether or not a group which is hyperbolic relative to abelian groups admits a nontrivial splitting over a finite group.

Jeremy S. Miller

In this paper, the contribution of hard processes described by the BFKL pomeron exchange, is taken into account by calculating the first enhanced diagram. The survival probability is estimated, using the ratio of the first enhanced diagram and the single pomeron amplitude, taking into account all essential pomeron loop diagrams in the toy model of Mueller. T

Shuguo Shi

In this paper we introduce the fourth fundamental form for the hypersurfaces in $H^{n+1}$ and the space-like hypersurfaces in $S_{1}^{n+1}$ and discuss the conformality of the normal Gauss maps of the hypersurfaces in $H^{n+1}$ and $S_{1}^{n+1}$. Particularly, we discuss the surfaces with conformal normal Gauss maps in $H^{3}$ and $S_{1}^{3}$ and prove a dua

Ismagil Habibullin, Asli Pekcan

Characteristic Lie algebras of semi-discrete chains are studied. The attempt to adopt this notion to the classification of Darboux integrable chains has been undertaken.

Marko Samer, Stefan Szeider

We present an efficient fixed-parameter algorithm for #SAT parameterized by the incidence treewidth, i.e., the treewidth of the bipartite graph whose vertices are the variables and clauses of the given CNF formula; a variable and a clause are joined by an edge if and only if the variable occurs in the clause. Our algorithm runs in time O(4^k k l N), where k

Kenji Morita, Shin Muroya, Hiroki Nakamura

We investigate degree of coherence of pion sources produced in relativistic heavy ion collisions using multi-particle interferometry. In order to obtain ``true&#39;&#39; chaoticity, lambda^true from two-pion correlation functions measured in experiments, we make a correction for long-lived resonance decay contributions. Using this lambda^true and the weight

Zhao Yang Zeng, Hong Li, Baowen Li

We investigate spin and charge current through a quantum dot pumped by a time-varying magnetic field. Using the density matrix method, quantum rate equations for the electronic occupation numbers in the quantum dot are obtained and solved in the stationary state limit for a wide set of setup parameters. Both charge and spin current are expressed explicitly i

Jinn-Ouk Gong

We study an inflationary model where two decoupled string axions drive inflation. The number of e-folds is dependent on the energy scale and the decay constant, but is almost independent of the angular component in spite of the rich geometry of the moduli space. This suppresses the nearly scale-invariant spectrum of the isocurvature perturbations, making the

Kanehisa Takasaki

The string equation of type $(2,2g+1)$ may be thought of as a higher order analogue of the first Painlevé equation that corresponds to the case of $g = 1$. For $g > 1$, this equation is accompanied with a finite set of commuting isomonodromic deformations, and they altogether form a hierarchy called the PI hierarchy. This hierarchy gives an isomonodromic ana

Alexander Dolgov, Diego N. Pelliccia

We show that if photon possesses a tiny but non-vanishing mass the universe cannot be electrically neutral. Cosmological electric asymmetry could be generated either at an early stage by different evaporation rates of primordial black holes with respect to positively and negatively charged particles or by predominant capture of protons in comparison to elect

Christian Corda

Following some ideas in the Landau book, some corrections about errors in the old literature on scalar gravitational waves are given and discussed. Even if such errors can be considered not important from the point of view of observations, because they do not alter the interferometric response function for scalar gravitational waves, the presented analysis i

S. I. Denisov, K. Sakmann, P. Talkner, P. Hänggi

The two-dimensional backward Fokker-Planck equation is used to calculate the mean first-passage times (MFPTs) of the magnetic moment of a nanoparticle driven by a rotating magnetic field. It is shown that a magnetic field that is rapidly rotating in the plane {\it perpendicular} to the easy axis of the nanoparticle governs the MFPTs just in the same way as a

Daniel H. Wesley

Compactification can control chaotic Mixmaster behavior in gravitational systems with p-form matter: we consider this in light of the connection between supergravity models and Kac-Moody algebras. We show that different compactifications define &#34;mutations&#34; of the algebras associated with the noncompact theories. We list the algebras obtained in this

Christian Corda

Recently, with an enlighting treatment, Baskaran and Grishchuk have shown the presence and importance of the so-called ``magnetic&#39;&#39; components of gravitational waves (GWs), which have to be taken into account in the context of the total response functions of interferometers for GWs propagating from arbitrary directions. In this paper the analysis of

H. Le Sueur, P. Joyez

The spectroscopic resolution of tunneling measurements performed with a scanning tunneling microscope is ultimately limited by the temperature at which the experiment is performed. To take advantage of the potential high spectroscopic resolution associated with operating an STM in a dilution refrigerator we have designed a room temperature tunnel current amp

H. Le Sueur, P. Joyez

In this article we report on the design, fabrication and tests of micro-fabricated broadband filters suitable for proper electromagnetic thermalization of electrical lines connected to sensitive quantum electronics experiments performed at dilution fridge temperatures. Compared to previous such miniature filters, the new design improves on performance and re

Viktor L. Ginzburg

We prove the Conley conjecture for a closed symplectically aspherical symplectic manifold: a Hamiltonian diffeomorphism of a such a manifold has infinitely many periodic points. More precisely, we show that a Hamiltonian diffeomorphism with finitely many fixed points has simple periodic points of arbitrarily large period. This theorem generalizes, for instan

Michael Bortz, Joachim Stolze

We calculate exactly the time-dependent reduced density matrix for the central spin in the central-spin model with homogeneous Heisenberg couplings. Therefrom, the dynamics and the entanglement entropy of the central spin are obtained. A rich variety of behaviors is found, depending on the initial state of the bath spins. For an initially unpolarized unentan

A. D. Beyer, C. -T. Chen, M. S. Grinolds, M. L. Teague

The low-energy quasiparticle excitations in hole- and electron-type cuprate superconductors are investigated via both experimental and theoretical means. It is found that the doping and momentum dependence of the empirical low-energy quasiparticle excitations is consistent with a scenario of coexisting competing orders and superconductivity in the ground sta

M. Wakamatsu

Very recently, a new measurement of the deuteron spin-dependent structure function $g_1^d (x)$ was reported by the COMPASS group. A main change from the old SMC measurement is a considerable improvement of the statistical accuracy in the low $x$ region $0.004 < x < 0.03$. We point out that the new COMPASS data for $g_1^d (x)$ as well as their QCD fits for $Δ

Chun-Hsiung Hsia, Tian Ma, Shouhong Wang

The main objective of this article is to study the dynamics of the stratified rotating Boussinesq equations, which are a basic model in geophysical fluid dynamics. First, for the case where the Prandtl number is greater than one, a complete stability and bifurcation analysis near the first critical Rayleigh number is carried out. Second, for the case where t

Saugata Basu, Michael Kettner

In this paper we consider the problem of bounding the Betti numbers, $b_i(S)$, of a semi-algebraic set $S \subset \R^k$ defined by polynomial inequalities $P_1 \geq 0,...,P_s \geq 0$, where $P_i \in \R[X_1,...,X_k]$ and $°(P_i) \leq 2$, for $1 \leq i \leq s$. We prove that for $0\le i\le k-1$, \[ b_i(S) \le{1/2}(\sum_{j=0}^{min\{s,k-i\}}{{s}\choose j}{{k+1}\

Joel Kamnitzer, Peter Tingley

Henriques and Kamnitzer defined and studied a commutor for the category of crystals of a finite dimentional complex reductive Lie algebra. We show that the action of this commutor on highest weight elements can be expressed very simply using Kashiwara&#39;s involution on the Verma crystal.

Alexei Tsygvintsev

We consider the Newtonian planar three--body problem with positive masses $m_1$, $m_2$, $m_3$. We prove that it does not have an additional first integral meromorphic in the complex neighborhood of the parabolic Lagrangian orbit besides three exceptional cases $ \sum m_i m_j/(\sum m_k)^2= 1/3$, $2^3/3^3$, $2/3^2$ where the linearized equations are shown to b

Ayaka Sakata, Masato Hisakado, Shintaro Mori

We introduce an infectious default and recovery model for N obligors. Obligors are assumed to be exchangeable and their states are described by N Bernoulli random variables S_{i} (i=1,...,N). They are expressed by multiplying independent Bernoulli variables X_{i},Y_{ij},Y&#39;_{ij}, and default and recovery infections are described by Y_{ij} and Y&#39;_{ij}.

Qing-Guo Huang

We not only reconstruct the slow-roll parameters for fit to the running spectral index from WMAP three-year data in the usual slow-roll inflation model and noncommutative inflation model, but also investigate the evolution of these slow-roll parameters. Requiring slow-roll inflation lasts more than 20 e-folds after CMB scales leave the horizon suggests that

J. J. Alvarez-Sanchez, J. V. Alvarez-Bravo, L. M. Nieto

A new quantum architecture for multiplying signed integers is presented based on Booth&#39;s algorithm, which is well known in classical computation. It is shown how a quantum binary chain might be encoded by its flank changes, giving the final product in 2&#39;s-complement representation.

Holger F. Hofmann, Ryo Okamoto, Shigeki Takeuchi

One of the challenges in quantum information is the demonstration of quantum coherence in the operations of experimental devices. While full quantum process tomography can do the job, it is both cumbersome and unintuitive. In this presentation, we show that a surprisingly detailed and intuitively accessible characterization of errors is possible by measuring

J. S. Hodges, P. Cappellaro, T. F. Havel, R. Martinez

Liquid phase NMR is a general purpose test-bed for developing methods of coherent control relevant to quantum information processing. Here we extend these studies to the coherent control of logical qubits and in particular to the unitary gates necessary to create entanglement between logical qubits. We report an experimental implementation of a conditional l

H. Brusheim-Johansson, J. Hansson

A new model is proposed for the purpose of modelling the ``wave function collapse&#39;&#39; of a two-state quantum system. The collapse to a classical state is driven by a nonlinear evolution equation with an extreme sensitivity to absolute phase. It is hypothesized that the phase, or part of it, is displaying chaotic behaviour. This chaotic behaviour can th

P. Cappellaro, J. S. Hodges, T. F. Havel, D. G. Cory

A critical step in experimental quantum information processing (QIP) is to implement control of quantum systems protected against decoherence via informational encodings, such as quantum error correcting codes, noiseless subsystems and decoherence free subspaces. These encodings lead to the promise of fault tolerant QIP, but they come at the expense of resou

Janet Anders, Vlatko Vedral

This paper summarises the results of our research on macroscopic entanglement in spin systems and free Bosonic gases. We explain how entanglement can be observed using entanglement witnesses which are themselves constructed within the framework of thermodynamics and thus macroscopic observables. These thermodynamical entanglement witnesses result in bounds o

B. H. Liu, F. W. Sun, Y. X. Gong, Y. F. Huang

Two schemes of projection measurement are realized experimentally to demonstrate the de Broglie wavelength of three photons without the need for a maximally entangled three-photon state (the NOON state). The first scheme is based on the proposal by Wang and Kobayashi (Phys. Rev. A {\bf 71}, 021802) that utilizes a couple of asymmetric beam splitters while th

J. I. Kim, V. S. Melezhik, P. Schmelcher

We demonstrate that scattering of particles strongly interacting in three dimensions (3D) can be suppressed at low energies in a quasi-one-dimensional (1D) confinement. The underlying mechanism is the interference of the s- and p-wave scattering contributions with large s- and p-wave 3D scattering lengths being a necessary prerequisite. This low-dimensional

A. J. Bennett, P. Atkinson, P. See, M. B. Ward

Compact and reliable sources of non-classical light could find many applications in emerging technologies such as quantum cryptography, quantum imaging and also in fundamental tests of quantum physics. Single self-assembled quantum dots have been widely studied for this reason, but the vast majority of reported work has been limited to optically excited sour

Janet Anders

We give an introduction to Gaussian states and operations. A discussion of the entanglement properties of bipartite Gaussian states in terms of its covariance matrix follows. It is explained how entanglement can be witnessed using feasible measurements, e.g. homodyne measurements. We find that the outcome of such a measurements cannot only witness but also q

Tarek Khalil, Jean Richert

We introduce an algorithm aimed to reduce the dimensions of Hilbert space. It is used here in order to study the behaviour of low energy states of strongly interacting quantum many-body systems at first order transitions and avoided crossings. The method is tested on different frustrated quantum spin ladders with two legs. The role and importance of symmetri

E. S. Kryachko

It is shown that the title Comment by W. Szczepanik, M. Dulak, and T. A. Wesolowski [Int. J. Quantum Chem. 106 (2006)] is unsatisfactory.

Ozlem Yesiltas

The solutions of trigonometric Scarf potential, PT/non-PT-symmetric and non-Hermitian q-deformed hyperbolic Scarf and Manning-Rosen potentials are obtained by solving the Schrodinger equation. The Nikiforov-Uvarov method is used to obtain the real energy spectra and corresponding eigenfunctions.

M. C. Tseng

In this note, we discuss dilation-theoretic matrix parametrizations of contractions and positive matrices. These parametrizations are then applied to some problems in quantum information theory. First we establish some properties of positive maps, or entanglement witnesses. Two further applications, concerning concrete dilations of completely positive maps,