September 2007 arXiv papers — page 26

Qi Chen, Srikanth Kuppum, Parthasarathy Srinivasan

The purpose of this note is to provide a simple relation between the Witten-Reshetikhin-Turaev SO(3) invariant and the Hennings invariant of 3-manifolds associated to quantum sl_2.

Allen Hatcher, Nathalie Wahl

We prove that the homology of the mapping class group of any 3-manifold stabilizes under connected sum and boundary connected sum with an arbitrary 3-manifold when both manifolds are compact and orientable. The stabilization also holds for the quotient group by twists along spheres and disks, and includes as particular cases homological stability for symmetr

Mu-in Park

Recently, the Heisenberg's uncertainty principle has been extended to incorporate the existence of a large (cut-off) length scale in de Sitter or anti-de Sitter space, and the Hawking temperatures of the Schwarzshild-(anti) de Sitter black holes have been reproduced by using the extended uncertainty principle. I generalize the extended uncertainty to the

Hajer Jebali

It is known, since works of Burde and de Rham, that one can detect the roots of the Alexander polynomial of a knot by the study of the representations of the knot group into the group of the invertible upper triangular $2x2$ matrices. In this work, we propose to generalize this result by considering the representations of the knot group into the group of the

Roberta Basili, Anthony Iarrobino

Let K be an infinite field and denote by H(n,K) the family of pairs (A,B) of commuting nilpotent n by n matrices with entries in K. There has been substantial recent study of the connection between H(n,K) and the fibre H[n] of the punctual Hilbert scheme of the plane, over an n-fold point of the symmetric product, by V. Baranovsky, R. Basili, and A. Premet.

B. J. Maughan, L. R. Jones, M. Pierre, S. Andreon

We present an analysis of deep XMM-Newton and Chandra observations of the z=1.05 galaxy cluster XLSSJ022403.9-041328 (hereafter XLSSC 029), detected in the XMM-Newton large scale structure survey. Density and temperature profiles of the X-ray emitting gas were used to perform a hydrostatic mass analysis of the system. This allowed us to measure the total mas

Gianfranco Bertone, Wilfried Buchmuller, Laura Covi, Alejandro Ibarra

We study the prospects for detecting gamma-rays from decaying Dark Matter (DM), focusing in particular on gravitino DM in R-parity breaking vacua. Given the substantially different angular distribution of the predicted gamma-ray signal with respect to the case of annihilating DM, and the relatively poor (of order 0.1$^\circ$) angular resolution of gamma-ray

A. W. Brookfield, C. van de Bruck, L. M. H. Hall

Cosmological observations have revealed the existence of a dark matter sector, which is commonly assumed to be made up of one particle species only. However, this sector might be more complicated than we currently believe: there might be more than one dark matter species (for example two components of cold dark matter or a mixture of hot and cold dark matter

B. Noyelles

In Noyelles et al. (2008, Astron. Astrophys., 478, 959-970), a resonance involving the wobble of Titan is hinted. This paper studies this scenario and its consequences. The first step is to build an accurate analytical model that would help to find the likely resonances in the rotation of every synchronous body. In this model, I take the orbital eccentricity

Z. Z. Aydin, L. Selbuz

We present the numerical investigation of the fermionic two-body decays of squarks in the Minimal Supersymmetric Standard Model with complex parameters. In the analysis we particularly take into account the cosmological bounds imposed by WMAP data. We find that the phase dependences of the decay widths of the third family squarks, as well as those of the fir

Mark Gross, Bernd Siebert

This paper continues the authors' program of studying mirror symmetry via log geometry and toric degenerations, relating affine manifolds with singularities, log Calabi-Yau spaces, and toric degenerations of Calabi-Yaus. The main focus of this paper is the calculation of the cohomology of a Calabi-Yau variety associated to a given affine manifold with si

Mark Grant

We employ Massey products to find sharper lower bounds for the Schwarz genus of a fibration than those previously known. In particular we give examples of non-formal spaces $X$ for which the topological complexity $\TC(X)$ (defined to be the genus of the free path fibration on $X$) is greater than the zero-divisors cup-length plus one.

Eric Hoffbeck

The aim of this article is to give a criterion, generalizing the criterion introduced by Priddy for algebras, to verify that an operad is Koszul. We define the notion of a Poincare-Birkhoff-Witt basis in the context of operads. Then we show that an operad having a Poincare-Birkhoff-Witt basis is Koszul. Besides, we obtain that the Koszul dual operad has also

Mikko Salo, Leo Tzou

We consider limiting Carleman weights for Dirac operators and prove corresponding Carleman estimates. In particular, we show that limiting Carleman weights for the Laplacian also serve as limiting weights for Dirac operators. As an application we consider the inverse problem of recovering a Lipschitz continuous magnetic field and electric potential from boun

M. Merano, A. Aiello, G. W. 't Hooft, M. P. van Exter

We report the first observation of the Goos-H$\rm \ddot{\textbf{a}}$nchen shift of a light beam incident on a metal surface. This phenomenon is particularly interesting because the Goos-H$\rm \ddot{\textbf{a}}$nchen shift for $p$ polarized light in metals is negative and much bigger than the positive shift for $s$ polarized light. The experimental result for

Anna Maria Pelczar

The relation between different notions measuring proximity to $\ell_1$ and distortability of a Banach space is studied. The main result states that a Banach space, whose all subspaces have Bourgain $\ell_1$ index greater than $ω^α$, $α<ω_1$, contains either an arbitrary distortable subspace or an $\ell_1^α$-asymptotic subspace.

R. P. Malik, B. P. Mandal

We demonstrate that the nilpotent Becchi-Rouet-Stora-Tyutin (BRST) and anti-BRST symmetry invariance of the Lagrangian density of a four (3 + 1)-dimensional (4D) non-Abelian 1-form gauge theory with Dirac fields can be captured within the framework of the superfield approach to BRST formalism. The above 4D theory, where there is an explicit coupling between

Xia-Ji Liu, Hui Hu, Peter D. Drummond

Recent advances in ultra-cold atomic Fermi gases make it possible to achieve a fermionic superfluid with multiple spin components. In this context, any mean-field description is expected to fail, owing to the presence of tightly bound clusters or molecules that consist of more than two particles. Here we present a detailed study of a strongly interacting mul

J. M. Carmona, J. L. Cortes, J. Indurain

An interpretation of neutrino oscillations based on a modification of relativistic quantum field theory at low energies, without the need to introduce a neutrino mass, is seen to be compatible with all observations.

R. Schulze, M. Bluhm, B. Kampfer

A phenomenological quasiparticle model is surveyed for 2+1 quark flavors and compared with recent lattice QCD results. Emphasis is devoted to the effects of plasmons, plasminos and Landau damping. It is shown that thermodynamic bulk quantities, known at zero chemical potential, can uniquely be mapped towards nonzero chemical potential by means of a thermodyn

Juergen Appel, Eden Figueroa, Dmitry Korystov, M. Lobino

We produce a 600-ns pulse of 1.86-dB squeezed vacuum at 795 nm in an optical parametric amplifier and store it in a rubidium vapor cell for 1 us using electromagnetically induced transparency. The recovered pulse, analyzed using time-domain homodyne tomography, exhibits up to 0.21+-0.04 dB of squeezing. We identify the factors leading to the degradation of s

Ll. Bel

Schwarzschild&#39;s solution of Einstein&#39;s field equations in vacuum can be written in many different forms. Unfortunately Schwarzschild&#39;s own original form is less nice looking and simple than that latter derived by Droste and Hilbert. We prove here that we can have both: a nice looking simple form and the meaning that Schwarzschild wanted to give t

Andreas Axelsson

We calculate explicitly solutions to the Dirichlet and Neumann boundary value problems in the upper half plane, for a family of divergence form equations with non symmetric coefficients with a jump discontinuity. It is shown that the boundary equation method and the Lax--Milgram method for constructing solutions may give two different solutions when the coef

T. Ezawa, H. Iwasaki, A. Nakamura, Y. Ohkuwa

We investigate the propagation of multidimensional gravitational waves generated before compactification and observes today as 4-dimensional gravitational waves and gauge fields by generalizing the investigation of Alesci and Montani(AM) to the case where the internal space is an n-sphere. We also derive the 4-dimensional forms of the multidimensional harmon

Yoav Moriah, Eric Sedgwick

Little is known on the classification of Heegaard splittings for hyperbolic 3-manifolds. Although Kobayashi gave a complete classification of Heegaard splittings for the exteriors of 2-bridge knots, our knowledge of other classes is extremely limited. In particular, there are very few hyperbolic manifolds that are known to have a unique minimal genus splitti

Gloria Sala, Jochen Greiner, Eugenio Bottacini, Frank Haberl

The black hole candidate XTE J1817-330 was discovered in outburst on 26 January 2006 with RXTE/ASM. One year later, on 28 February 2007, another X-ray transient discovered in 1996, XTE J1856+053, was detected by RXTE during a new outburst. We report on the spectra obtained by XMM-Newton of these two black hole candidates.

Ryszard Szwarc

The convergence of the algorithm for solving convex feasibility problem is studied by the method of sequential averaged and relaxed projections. Some results of H. H. Bauschke and J. M. Borwein are generalized by introducing new methods. Examples illustrating these generalizations are given.

Victor H. de la Peña, Michael J. Klass, Tze Leung Lai

Self-normalized processes are basic to many probabilistic and statistical studies. They arise naturally in the the study of stochastic integrals, martingale inequalities and limit theorems, likelihood-based methods in hypothesis testing and parameter estimation, and Studentized pivots and bootstrap-$t$ methods for confidence intervals. In contrast to standar

Y. Kikukawa, M. Kohda, J. Yasuda

It has been argued by Pisarski and Wilczek that finite temperature restoration of the chiral symmetry SU(Nf) x SU(Nf) is first-order for Nf >=3. This type of chiral symmetry with a large Nf may appear in the Higgs sector if one considers models such as walking technicolor theories. We examine the first-order restoration of the chiral symmetry from the point

David F. Mota, Douglas J. Shaw, Joseph Silk

We investigate the clustering of dark energy within matter overdensities and voids. In particular, we derive an analytical expression for the dark energy density perturbations, which is valid both in the linear, quasi-linear and fully non-linear regime of structure formation. We also investigate the possibility of detecting such dark energy clustering throug

Jean-Yves Fortin, Alain Audouard

The field and temperature dependence of the de Haas-van Alphen oscillations spectrum is studied for an ideal two-dimensional compensated metal. It is shown that the chemical potential oscillations, involved in the frequency combinations observed in the case of uncompensated orbits, are strongly damped and can even be suppressed when the effective masses of t

Zhi-zhong Xing

The evidence for neutrino oscillations implies that three neutrino flavors (ν_e, ν_μ, ν_τ) must have different mass states (ν_1, ν_2, ν_3). The most popular idea of generating tiny masses of ν_i is to introduce three heavy Majorana neutrinos N_i (for i = 1, 2, 3) into the standard model and implement the seesaw mechanism. In this approach the neutrino mixing

Ramon van Handel

When are quantum filters asymptotically independent of the initial state? We show that this is the case for absolutely continuous initial states when the quantum stochastic model satisfies an observability condition. When the initial system is finite dimensional, this condition can be verified explicitly in terms of a rank condition on the coefficients of th

Jun O&#39;Hara

A two-component link produces a torus as the product of the component knots in a two-point configuration space of a three-sphere. This space can be identified with a cotangent bundle and also with an indefinite Grassmannian. We show that the integration of the absolute value of the canonical symplectic form is equal to the area of the torus with respect to t

Mahito Kohmoto

Electron hopping models on the honeycomb lattice are studied. The lattice consists of two triangular sublattices, and it is non-Bravais. The dual space has non-trivial topology. The gauge fields of Bloch electrons have the U(1) symmetry and thus represent superconducting states in the dual space. Two quantized Abrikosov fluxes exist at the Dirac points and h

Yasunori Fujii

We present a theoretical calculation on the time-variability of the fine-structure constant to fit the result of the recent precise analysis of the measurement of the QSO absorption lines. We find the parameters and initial values of the scalar-tensor theory to be determined much more accurately than fitting the accelerating universe itself, but leading not

Koji Hashimoto, Chung-I Tan, Seiji Terashima

Using holographic QCD based on D4-branes and D8-anti-D8-branes, we have computed couplings of glueballs to light mesons. We describe glueball decay by explicitly calculating its decay widths and branching ratios. Interestingly, while glueballs remain less well understood both theoretically and experimentally, our results are found to be consistent with the e

J. A. S. Lima, J. F. Jesus, J. V. Cunha

A new age-redshift test is proposed in order to constrain $H_0$ with basis on the existence of old high redshift galaxies (OHRG). As should be expected, the estimates of $H_0$ based on the OHRG are heavily dependent on the cosmological description. In the flat concordance model ($Λ$CDM), for example, the value of $H_0$ depends on the mass density parameter $

G. Herring, L. D. Carr, R. Carretero-Gonzalez, P. G. Kevrekidis

Starting from the spectrum of the radially symmetric quantum harmonic oscillator in two dimensions, we create a large set of nonlinear solutions. The relevant three principal branches, with $n_r=0,1$ and 2 radial nodes respectively, are systematically continued as a function of the chemical potential and their linear stability is analyzed in detail, in the a

Jesús A. De Loera, Edward D. Kim, Shmuel Onn, Francisco Santos

This paper discusses properties of the graphs of 2-way and 3-way transportation polytopes, in particular, their possible numbers of vertices and their diameters. Our main results include a quadratic bound on the diameter of axial 3-way transportation polytopes and a catalogue of non-degenerate transportation polytopes of small sizes. The catalogue disproves

K. Yi

We report the first observation of $e^+e^-$ annihilations into hadronic states of positive $C$-parity, $ρ^0 ρ^0$ and $ϕρ^0$. The angular distributions support two-virtual-photon annihilation production. We also report the observations of $e^+e^-\to ϕη$ and a preliminary result on $e^+e^-\to ρ^+ρ^-$.

L. H. Eliasson, S. B. Kuksin

We consider the $d$-dimensional nonlinear Schrödinger equation under periodic boundary conditions: $-i\dot u=-Δu+V(x)*u+\ep \frac{\p F}{\p \bar u}(x,u,\bar u), \quad u=u(t,x), x\in\T^d $ where $V(x)=\sum \hat V(a)e^{i\sc{a,x}}$ is an analytic function with $\hat V$ real, and $F$ is a real analytic function in $\Re u$, $\Im u$ and $x$. (This equation is a pop

T Morishita, A. T. Le, Z. Chen, C. D. Lin

We studied the photoelectron spectra generated by an intense few-cycle infrared laser pulse. By focusing on the angular distributions of the back rescattered high energy photoelectrons, we show that accurate differential elastic scattering cross sections of the target ion by free electrons can be extracted. Since the incident direction and the energy of the

Andrew Neitzke, Johannes Walcher

The open topological string partition function in the background of a D-brane on a Calabi-Yau threefold specifies a state in the Hilbert space associated with the quantization of the underlying special geometry. This statement is a consequence of the extended holomorphic anomaly equation after an appropriate shift of the closed string variables, and can be v

J. Greensite, S. Olejnik

A gauge-invariant wavefunctional is proposed as an approximation to the ground state of Yang-Mills theory in 2+1 dimensions, quantized in temporal gauge. The proposed vacuum state is the true ground state of the appropriate Hamiltonian in both the free-field limit, and in a zero mode strong-field limit. Confinement, in this approach, arises via dimensional r

Katherine Freese, Paolo Gondolo, Douglas Spolyar

Dark matter (DM) in protostellar halos can dramatically alter the current theoretical framework for the formation of the first stars. Heat from supersymmetric DM annihilation can overwhelm any cooling mechanism, consequently impeding the star formation process and possibly leading to a new stellar phase. The first stars to form in the universe may be ``dark

D. K. Sinclair, J. B. Kogut

We simulate 3-flavour lattice QCD at finite quark-number chemical potential mu in the phase-quenched approximation, close to the finite temperature transition. Working close to the critical quark mass, we find no evidence for the expected critical endpoint at small mu. We are performing further simulations aimed at calculating the equation-of-state of this t

J. F. Carinena, J. Clemente-Gallardo, G. Marmo

We present, in a pedagogical style, many instances of reduction procedures appearing in a variety of physical situations, both classical and quantum. We concentrate on the essential aspects of any reduction procedure, both in the algebraic and geometrical setting, elucidating the analogies and the differences between the classical and the quantum situations.

Martin Bojowald, Golam Mortuza Hossain

Cosmological tensor perturbations equations are derived for Hamiltonian cosmology based on Ashtekar&#39;s formulation of general relativity, including typical quantum gravity effects in the Hamiltonian constraint as they are expected from loop quantum gravity. This translates to corrections of the dispersion relation for gravitational waves. The main applica

Eli Visbal, Rupert A. C. Croft

The UV radiation from a quasar leaves a characteristic pattern in the distribution of ionized hydrogen throughout the surrounding space. This pattern or light echo propagates through the intergalactic medium at the speed of light, and can be observed by its imprint on the Ly-alpha forest spectra of background sources. As the echo persists after the quasar ha

MAGIC Collaboration, Florian Goebel, Hendrik Bartko, Emiliano Carmona

In February 2007 the MAGIC Air Cherenkov Telescope for gamma ray astronomy was fully upgraded with a fast 2 GSamples/s digitization system. The upgraded readout system uses a novel fiber-optic multiplexing technique. It consists of 10-bit 2 GSamples/s FADCs to digitize 16 channels consecutively and optical fibers to delay the analog signals. A distributed da

Rupert A. C. Croft, Gabriel Altay

The structures produced during the epoch of reionization by the action of radiation on neutral hydrogen are in principle different to those that arise through gravitational growth of initially small perturbations. We explore the difference between the two mechanisms using high resolution cosmological radiative transfer. Our computations use a Monte Carlo cod

M. Gaudiano, O. Osenda, G. A. Raggio

We consider the two-spin subsystem entanglement for eigenstates of the Hamiltonian \[ H= \sum_{1\leq j< k \leq N} (\frac{1}{r_{j,k}})^α {\mathbf σ}_j\cdot {\mathbf σ}_k \] for a ring of $N$ spins 1/2 with asssociated spin vector operator $(\hbar /2){\bf σ}_j$ for the $j$-th spin. Here $r_{j,k}$ is the chord-distance betwen sites $j$ and $k$. The case $α=2$ c

Sourendu Gupta

A systematic expansion of the Boltzmann equation for the diffusion of dilute tracers, in powers of the Knudsen number, carried out to next-to-leading order (NLO), gives the relativistic causal diffusion equation (Kelly&#39;s equation). Using dimensionless combinations of dynamical quantities, we show when the small NLO term plays a crucially important role.

Jacco Th. van Loon, Floor van Leeuwen, Barry Smalley, Andrew W. Smith

We present a spectral atlas of the post-main-sequence population of the most massive Galactic globular cluster, omega Centauri. Spectra were obtained of more than 1500 stars selected as uniformly as possible from across the (B, B-V) colour-magnitude diagram of the proper motion cluster member candidates of van Leeuwen et al. (2000). The spectra were obtained

Michael A. Lomholt, Tal Koren, Ralf Metzler, Joseph Klafter

Search strategies based on random walk processes with long-tailed jump length distributions (Levy walks) on the one hand and intermittent behavior switching between local search and ballistic relocation phases on the other, have been previously shown to be beneficial in stochastic target finding problems. We here study a combination of both mechanisms: an in

M. Hayashida, C. Bigongiari, D. Kranich, A. Moralejo

Simultaneous multiwavelength observations were conducted for the BL Lac object 1ES1959+650 in a steady state in May 2006 with the MAGIC telescope and the X-ray satellites Suzaku and Swift. Swift can also provide multi-filter photometry in the UV-optical band. The source was clearly detected in all observed energy bands, from the optical to TeV. With respect

R. Jackiw

In a diffeomorphism invariant theory, symmetry breaking may be a mask for coordinate choice.

Herman L. Marshall

A novel approach for measuring linear X-ray polarization over a broad-band using conventional imaging optics and cameras is described. A new type of high efficiency grating, called the critical angle transmission grating is used to disperse soft X-rays radially from the telescope axis. A set of multilayer-coated paraboloids re-image the dispersed X-rays to r

Mika A. Sillanpaa, Jae I. Park, Raymond W. Simmonds

A network of quantum-mechanical systems showing long lived phase coherence of its quantum states could be used for processing quantum information. As with classical information processing, a quantum processor requires information bits (qubits) that can be independently addressed and read out, long-term memory elements to store arbitrary quantum states, and t

Gitta Kutyniok, Ali Pezeshki, Robert Calderbank, Taotao Liu

We consider estimating a random vector from its noisy projections onto low dimensional subspaces constituting a fusion frame. A fusion frame is a collection of subspaces, for which the sum of the projection operators onto the subspaces is bounded below and above by constant multiples of the identity operator. We first determine the minimum mean-squared error

Kenneth A. Brown, Kanokporn Changtong

Basic properties of symplectic reflection algebras over an algebraically closed field k of positive characteristic are laid out. These algebras are always finite modules over their centres, in contrast to the situation in characteristic 0. For the subclass of rational Cherednik algebras, we determine the PI-degree and the Goldie rank, and show that the Azuma

Nancy Marinelli

While approaching the start of the data taking at the LHC, ATLAS and CMS perform studies involving the Higgs boson within non-minimal models besides Supersymmetric models. Highlights from both experiments are summarized; all results refer to LHC low luminosity conditions of 10^33 cm^-2 s^-1.

Kenneth A. Brown

This short survey article reviews current understand- ing of the structure of noetherian Hopf algebras. The focus is on homological properties. A number of open problems are listed.

Giovanni Ossola

We recently presented a new method for the evaluation of one-loop amplitude of arbitrary scattering processes, in which the reduction to scalar integrals is performed at the integrand level. In this talk, we review the main features of the method and briefly summarize the results of the first calculations performed using it.

L. Gyorfi, G. Morvai

In this paper we revisit the results of Loynes (1962) on stability of queues for ergodic arrivals and services, and show examples when the arrivals are bounded and ergodic, the service rate is constant, and under stability the limit distribution has larger than exponential tail.

I. V. Chelovekov, S. A. Grebenev, R. A. Sunyaev

All the observations performed with the IBIS telescope aboard the INTEGRAL observatory during the first 2.5 years of its in-orbit operation have been analyzed to find X-ray bursts. There were 1788 statistically confident events with a duration from 5 to 500 s revealed in time records of the 15-25 keV count rate of the IBIS/ISGRI detector, 319 of them were lo

A. Redinger, O. Ricken, P. Kuhn, A. Raetz

The growth of spiral mounds containing a screw dislocation is compared to the growth of wedding cakes by two-dimensional nucleation. Using phase field simulations and homoepitaxial growth experiments on the Pt(111) surface we show that both structures attain the same characteristic large scale shape when a significant step edge barrier suppresses interlayer

Gordon Blower

Integrable operators arise in random matrix theory, where they describe the asymptotic eigenvalue distributions of large self-adjoint random matrices from the generalized unitary ensembles. This paper gives sufficient conditions for an integrable operator to be the square of a Hankel operator, and applies the condition to the Airy, associated Laguerre, modif

Richard Kenyon, Peter Winkler

Building on and from the work of Brydges and Imbrie, we give an elementary calculation of the volume of the space of branched polymers of order $n$ in the plane and in 3-space. Our development reveals some more general identities, and allows exact random sampling. In particular we show that a random 3-dimensional branched polymer of order $n$ has diameter of

Jesper Lykke Jacobsen

We present a Monte Carlo method that allows efficient and unbiased sampling of Hamiltonian walks on a cubic lattice. Such walks are self-avoiding and visit each lattice site exactly once. They are often used as simple models of globular proteins, upon adding suitable local interactions. Our algorithm can easily be equipped with such interactions, but we stud

Jesper Lykke Jacobsen

We present an algorithm for enumerating exactly the number of Hamiltonian chains on regular lattices in low dimensions. By definition, these are sets of k disjoint paths whose union visits each lattice vertex exactly once. The well-known Hamiltonian circuits and walks appear as the special cases k=0 and k=1 respectively. In two dimensions, we enumerate chain

Y. Imry, M. Strongin, C. C. Homes

In many cases inhomogeneities are known to exist near the metal (or superconductor)-insulator transition, as follows from well-known domain-wall arguments. If the conducting regions are large enough (i.e. when the T=0 superconducting gap is much larger than the single-electron level spacing), and if they have superconducting correlations, it becomes energeti

Orion Ciftja, Carlos Wexler

We discuss an alternative accurate Monte Carlo method to calculate the ground-state energy and related quantities for Laughlin states of the fractional quantum Hall effect in a disk geometry. This alternative approach allows us to obtain accurate bulk regime (thermodynamic limit) values for various quantities from Monte Carlo simulations with a small number

V. M. Braun, D. Yu. Ivanov, A. Peters

We consider pion electroproduction on a proton target close to threshold for Q^2 in the region 1-10 GeV^2. The momentum transfer dependence of the S-wave multipoles at threshold, E_{0+} and L_{0+}, is calculated using light-cone sum rules.

J. Lember, A. Koloydenko

To estimate the emission parameters in hidden Markov models one commonly uses the EM algorithm or its variation. Our primary motivation, however, is the Philips speech recognition system wherein the EM algorithm is replaced by the Viterbi training algorithm. Viterbi training is faster and computationally less involved than EM, but it is also biased and need

Szabolcs Borsanyi, Urko Reinosa

We compute the pressure of hot quantum electrodynamics from the two-loop truncation of the 2PI effective action. Since the 2PI resummation guarantees gauge-fixing independence only up to the order of the truncation, our result for the pressure presents a gauge dependent contribution of O(e^4). We numerically characterize the credibility of this gauge-depende

Sylvain Latil, Vincent Meunier, Luc Henrard

We examine how the misorientation of a few stacked graphene layers affects the electronic structure of carbon nanosystems. We present {\it ab initio} calculations on bi- and trilayer systems to demonstrate that the massless Fermion behavior typical of single layered graphene is also found in incommensurate multilayered graphitic systems. We also investigate

Yu. G. Kusrayev, K. V. Kavokin, G. V. Astakhov, W. Ossau

We study bound magnetic polarons (BMP) in a very diluted magnetic semiconductor CdMnTe by means of site selective spectroscopy. In zero magnetic field we detect a broad and asymmetric band with a characteristic spectral width of about 5 meV. When external magnetic fields are applied a new line appears in the emission spectrum. Remarkably, the spectral width

S. A. Grebenev, S. V. Molkov, M. G. Revnivtsev, R. A. Sunyaev

We report the discovery with INTEGRAL on March 24, 2005, and follow-up observations of the distant Galactic X-ray nova IGR J17098-3628.

A. F. Krutov, V. E. Troitsky, N. A. Tsirova

A theorem about asymptotic estimation of multiple integral of a special type is proved for the case when the integrand peaks at the integration domain bound, but not at a point of extremum. Using this theorem the asymptotic expansion of the electromagnetic deuteron form factors at high momentum transfers is obtained in the framework of two-nucleon model in b

Bernd Jantzen

Recently the two-loop next-to-leading logarithmic (NLL) virtual corrections to arbitrary processes with massless external fermions have been calculated. Within the spontaneously broken electroweak theory the one- and two-loop mass singularities have been derived to NLL accuracy and expressed as universal correction factors depending only on the quantum numbe

Cristina C. Popescu, Richard J. Tuffs

Modelling the UV/optical - infrared/submm SEDs of spiral galaxies observed with Herschel will be an essential tool to quantitatively interpret these observations in terms of the present and past star-formation activity of these systems. In this lecture we describe the SED modelling technique we have developed, its applications and tests of its predictions. W

Milan M. Cirkovic

One of the mainstays of the controversial &#34;rare Earth&#34; hypothesis is the &#34;Goldilocks problem&#34; regarding various parameters describing a habitable planet, partially involving the role of mass extinctions and other catastrophic processes in biological evolution. Usually, this is construed as support for the uniqueness of the Earth&#39;s biosphe

Susanne Pumpluen

Albert algebras and other Jordan algebras are constructed over curves of genus zero and one, using a generalization of the Tits process and the first Tits construction due to Achhammer.

T. Kojima, J. Shiraishi

We explicitly construct two classes of infinitly many commutative operators in terms of the deformed W-algebra $W_{qt}(sl_N^)$, and give proofs of the commutation relations of these operators. We call one of them local integrals of motion and the other nonlocal one, since they can be regarded as elliptic deformation of local and nonlocal integrals of motion

P. Chudzinski, M. Gabay, T. Giamarchi

In the weak coupling limit, we establish the phase diagram of a two-leg ladder with a unit cell containing both Cu and O atoms, as a function of doping. We use bosonization and design a specific RG procedure to handle the additional degrees of freedom. Significant differences are found with the single orbital case; for purely repulsive interactions, a comple

Dongwon Shin, Axel van de Walle, Yi Wang, Zi-Kui Liu

In the present work, ternary Special Quasirandom Structures (SQSs) for a fcc solid solution phase are generated at different compositions, $x_A=x_B=x_C=\tfrac{1}{3}$ and $x_A=\tfrac{1}{2}$, $x_B=x_C=\tfrac{1}{4}$, whose correlation functions are satisfactorily close to those of a random fcc solution. The generated SQSs are used to calculate the mixing enthal

P. Finelli

A recently introduced relativistic nuclear energy density functional, constrained by features of low-energy QCD, is extended to describe the structure of hypernuclei. The density-dependent mean field and the spin-orbit potential of a $Λ$-hyperon in a nucleus, are consistently calculated using the SU(3) extension of in-medium chiral perturbation theory. The l

Serguei Brazovskii

We suggest a short review of literature on various solitonic lattices and individual solitons in quasi one-dimensional conductors. This information seems to be quite relevant to topics of stripes and their melted phases correspondingly. We shall quote also the latest experiments, which access solitons as elementary excitations in organic conductors and in ch

Zhi-Gang Wang

In this article, we study the contribution from the final-state interactions to the strong coupling constant $g_{D^* D π}$. We take an assumption that the momentum transfers in the strong decay $D^{*+} \to D^0 π^+$ be large to validate the operator product expansion in the light-cone QCD sum rules. At large momentum transfers, the final-state interactions pl

Marius Ionescu, Paul S. Muhly

We describe how the Deaconu-Renault groupoid may be used in the study of wavelets and fractals.

R. G. Edgar, J. Nordhaus, E. Blackman, A. Frank

As stars evolve along the Asymptotic Giant Branch, strong winds are driven from the outer envelope. These winds form a shell, which may ultimately become a planetary nebula. Many planetary nebulae are highly asymmetric, hinting at the presence of a binary companion. Some post-Asymptotic Giant Branch objects are surrounded by torii of crystalline dust, but th

T. Amdeberhan, L. Medina, Victor H. Moll

Let t[n] be a sequence that satisfies a first order homogeneous recurrence t[n] = Q[n]*t[n-1], where Q is a polynomial with integer coefficients. The asymptotic behavior of the p-adic valuation of t[n] is described under the assumption that all the roots of Q in Z/pZ have nonvanishing derivative.

J. Rico, M. Rissi, P. Bordas, V. Bosch-Ramon

We report on the results from the observations in very high energy band (VHE, E_gamma > 100GeV) of the black hole X-ray binary (BHXB) Cygnus X-1. The observations were performed with the MAGIC telescope, for a total of 40 hours during 26 nights, spanning the period between June and November 2006. We report on the results of the searches for steady and variab

S. E. de Mink, O. R. Pols, E. Glebbeek

In close binaries mass and angular momentum can be transferred from one star to the other during Roche-lobe overflow. The efficiency of this process is not well understood and constitutes one of the largest uncertainties in binary evolution. One of the problems lies in the transfer of angular momentum, which will spin up the accreting star. In very tight sys

E. Lytvynov, P. T. Polara

We deal with two following classes of equilibrium stochastic dynamics of infinite particle systems in continuum: hopping particles (also called Kawasaki dynamics), i.e., a dynamics where each particle randomly hops over the space, and birth-and-death process in continuum (or Glauber dynamics), i.e., a dynamics where there is no motion of particles, but rathe

J. Rico, E de Ona-Wilhelmi, J. Cortina, E. Lorenz

We study the capability of the MAGIC telescope to observe under moderate moonlight. TeV gamma-ray signals from the Crab nebula were detected with the MAGIC telescope during periods when the Moon was above the horizon and during twilight. This was accomplished by increasing the trigger discriminator thresholds. No change is necessary in the high voltage setti

Alberto Marrero, Paul S. Muhly

Inspired by the work of Paterson on $C^{\ast}$-algebras of directed graphs, we show how to associate a groupoid $\mathfrak{G}_{\mathcal{G}}$ to an ultragraph $\mathcal{G}$ in such a way that the $C^*$-algebra of $\mathfrak{G}_{\mathcal{G}}$ is canonically isomorphic to Tomforde&#39;s $C^*$-algebra $C^*(\mathcal{G})$. The groupoid $\mathfrak{G}_{\mathcal{G}}$

Ruifang Dong, Joel Heersink, Joel F. Corney, Peter D. Drummond

We report new experiments on polarization squeezing using ultrashort photonic pulses in a single pass of a birefringent fiber. We measure what is to our knowledge a record squeezing of -6.8 +/- 0.3 dB in optical fibers which when corrected for linear losses is -10.4 +/- 0.8 dB. The measured polarization squeezing as a function of optical pulse energy, which