July 2004 arXiv papers — page 9

Michael D. Hartl, Alessandra Buonanno

We investigate the (conservative) dynamics of binary black holes using the Hamiltonian formulation of the post-Newtonian (PN) equations of motion. The Hamiltonian we use includes spin-orbit coupling, spin-spin coupling, and mass monopole/spin-induced quadrupole interaction terms. In the case of both quasi-circular and eccentric orbits, we search for the pres

Andrea Montanari

A new method for analyzing low density parity check (LDPC) codes and low density generator matrix (LDGM) codes under bit maximum a posteriori probability (MAP) decoding is introduced. The method is based on a rigorous approach to spin glasses developed by Francesco Guerra. It allows to construct lower bounds on the entropy of the transmitted message conditio

J. Röhler

The bulge in the doping dependence of the basal plane area of cuprate superconductors is shown to be an effect of the particular inhomogenous electronic structure created by the dense packing of paired self-protected singlets (PSPS) in CuO_2 lattices.

Yu-xi Liu, L. F. Wei, Franco Nori

We propose an approach to reconstruct any superconducting charge qubit state by using quantum state tomography. This procedure requires a series of measurements on a large enough number of identically prepared copies of the quantum system. The experimental feasibility of this procedure is explained and the time scales for different quantum operations are est

Baburaj A. Puthenveettil, G. Ananthakrishna, Jaywant H. Arakeri

The geometrically different plan forms of near wall plume structure in turbulent natural convection, visualised by driving the convection using concentration differences across a membrane, are shown to have a common multifractal spectrum of singularities for Rayleigh numbers in the range $10^{10}- 10^{11}$ at Schmidt number of 602. The scaling is seen for a

Lu Guo, Jie Meng, Enguang Zhao, Fumihiko Sakata

The damping of collective rotational motion is investigated by means of particles-rotor model in which the angular momentum coupling is treated exactly and the valence nucleons are in a multi-$j$ shell mean-field. It is found that the onset energy of rotational damping is around 1.1 MeV above yrast line, and the number of states which form rotational band st

J. P. Huang

The usual approach to the development of new nonlinear dielectric materials focuses on the search for materials in which the components possess an inherently large nonlinear dielectric response. In contrast, based on thermodynamics, we have presented a first-principles approach to obtain the electrostriction-induced effective third-order nonlinear susceptibi

J. P. Huang

The mesocrystal showing both electrorheological and magnetorheological effects is called electro-magnetorheological (EMR) solids. Prediction of the overall magnetic properties of the EMR solids is a challenging task due to the coexistence of the uniaxially anisotropic behavior and structural transition as well as long-range interaction between the suspended

J. P. Huang, K. W. Yu

We study the effective second-harmonic generation (SHG) susceptibility in graded metallic films by invoking the local field effects exactly, and further numerically demonstrate that the graded metallic films can serve as a novel optical material for producing a broad structure in both the linear and SHG response and an enhancement in the SHG signal.

Namiko Mitarai, Hiizu Nakanishi

We investigate the bulk rheology of dense granular flow down a rough slope, where the density profile has been found to show a plateau except for the boundary layers in simulations [Silbert {\it et al.}, Phys. Rev. E {\bf 64}, 051302 (2001)]. It is demonstrated that both the Bagnold scaling and the framework of kinetic theory are applicable in the bulk, whic

J. P. Huang, C. Holm

We exploit magnetostriction in polydisperse ferrofluids in order to generate nonlinear responses, and apply a thermodynamical method to derive the desired nonlinear magnetic susceptibility. For an ideal gas, this method has been demonstrated to be in excellent agreement with a statistical method. In the presence of a sinusoidal ac magnetic field, the magneti

J. P. Huang

Conductive organic polymers can be formulated with polymers that incorporate fine dispersed metallic particles. In this work, we present a general model for ferrogels which are chemically cross-linked polymer networks swollen with a ferrofluid. Our aim is to study the effect of the shape and/or material (conductivity) anisotropy on the effective electrical c

Sergei V. Ketov, Shin Sasaki

We derive the master function governing the component action of the four-dimensional non-anticommutative (NAC) and fully N=2 supersymmetric gauge field theory with a non-simple gauge group U(2)=SU(2)xU(1). We use a Lorentz singlet NAC-deformation parameter and an N=2 supersymmetric star (Moyal) product which do not break any of the fundamental symmetries of

Peter G Doyle, Juan Pablo Rossetti

We introduce a pair of isospectral but non-isometric compact flat 3-manifolds called Tetra (a tetracosm) and Didi (a didicosm). The closed geodesics of Tetra and Didi are very different. Where Tetra has two quarter-twisting geodesics of the shortest length, Didi has four half-twisting geodesics. Nevertheless, these spaces are isospectral. This isospectrality

Virendra Gupta

It is suggested that the narrow meson state seen in the the SELEX experiment is a $(c\bar{s} s\bar{s})$ tetraquark state. Characteristics of other possible tetraquarks formed out of $c$ and $s$ quarks and antiquarks are considered.

Afshin Shafiee, Mehdi Golshani

Two new formulations of Bell's theorem are given here. First, we consider a definite set of two entangled photons with only two polarization directions, for which Bell's locality assumption is violated for the case of perfect correlation. Then, using a different approach, we prove an efficient Bell-type inequality which is violated by some quantum me

P. Zhang, H. T. Quan, C. P. Sun

We, based on the photoassociation of fermion atoms into bosonic molecules, propose a scheme to create the steady entanglement between the atom state and the molecule state inside an optical lattice. The stability of entanglement state is guaranteed by sweeping the frequency of Ramman laser beam through resonance according to the second Demkov-Kunike (DK2) no

Ambarish Kunwar

Recently we have extended our the "unified" model of evolutionary ecology to incorporate the {\it spatial inhomogeneities} of the eco-system and the {\it migration} of individual organisms from one patch to another within the same eco-system. In this paper an extension of our recent model is investigated so as to describe the {\it migration} and {\it

M. Zamboni-Rached

In this paper it is shown how one can use Bessel beams to obtain a stationary localized wavefield with high transverse localization, and whose longitudinal intensity pattern can assume any desired shape within a chosen interval 0 < z < L of the propagation axis. This intensity envelope remains static, i.e., with velocity v=0; and because of this we call &#34

Steven K. Morrison, Yuri S. Kivshar

We analyze, by the finite-difference time-domain numerical methods, several ways to enhance the directional emission from photonic crystal waveguides through the beaming effect recently predicted by Moreno et al. [Phys. Rev. E 69, 121402(R) (2004)], by engineering the surface modes and corrugation of the photonic crystal surface. We demonstrate that the subs

J. H. O. Sales

Gauge fields are special in the sense that they are invariant under gauge transformations and they lead to problems when we try quantizing them straightforwardly. To circumvent this problem we need to specify a gauge condition to fix gauge.

Michael Forger, Cornelius Paufler, Hartmann Römer

We present a general classification of Hamiltonian multivector fields and of Poisson forms on the extended multiphase space appearing in the geometric formulation of first order classical field theories. This is a prerequisite for computing explicit expressions for the Poisson bracket between two Poisson forms.

G. C. Bell, A. N. Dranishnikov

We prove an asymptotic analog of the classical Hurewicz theorem on mappings which lower dimension. This theorem allows us to find sharp upper bound estimates for the asymptotic dimension of groups acting on finite dimensional metric spaces and allows us to prove a useful extension theorem for asymptotic dimension. As applications we find upper bound estimate

Qing Xiang

We survey recent results on $p$-ranks and Smith normal forms of some $2-(v,k,λ)$ designs. In particular, we give a description of the recent work in \cite{csx} on the Smith normal forms of the 2-designs arising from projective and affine spaces over $\Ff_q$.

Henk D. L. Hollmann, Qing Xiang

We construct a class of permutation polynomials of $\bF_{2^m}$ that are closely related to Dickson polynomials.

James A. Davis, Qing Xiang

Combining results on quadrics in projective geometries with an algebraic interplay between finite fields and Galois rings, we construct the first known family of partial difference sets with negative Latin square type parameters in nonelementary abelian groups, the groups $\Z_4^{2k}\times \Z_2^{4 \ell-4k}$ for all $k$ when $\ell$ is odd and for all $k < \ell

Matthew Baker, Liang-Chung Hsia

Let phi(z) be a polynomial of degree at least 2 with coefficients in a number field K. Iterating phi gives rise to a dynamical system and a corresponding canonical height function, as defined by Call and Silverman. We prove a simple product formula relating the transfinite diameters of the filled Julia sets of phi over various completions of K, and we apply

Michael Faux, David Kagan, Donald Spector

We systematically include central charges into supersymmetric quantum mechanics formulated on curved Euclidean spaces, and explain how the background geometry manifests itself on states of the theory. In particular, we show in detail how, from the point of view of non-relativistic d=1 world-line physics, one can infer the existence of target space dualities

Wojciech Broniowski, Wojciech Florkowski, Leonid Ya. Glozman

We present an update of the Hagedorn hypothesis of the exponential growth of the number of hadronic resonances with mass. We use the newest available experimental data for the non-strange mesons and baryons, as well as fill in some missing states according to the observation that the high-lying states form chiral multiplets. The results show, especially for

D. V. Efremov, D. I. Khomskii

We consider the orbital ordering in LaMnO3 and similar systems, proceeding from the band picture. We show that for the realistic magnetic structure of A-type there exists a complete nesting betweeen two e_g-bands. As a result there occurs an instability towards an excitonic insulator-like state -- an electron-hole pairing with the wave vector Q=(π,π), which

Luca Salasnich

The properties of triaxial bright solitons (TBSs) made of attractive Bose-Einstein condensed atoms under transverse anisotropic harmonic confinement are investigated by using a variational approach. We show that these metastable TBSs change their shape from cigar-like to disc-like by increasing the inter-atomic strength. Moreover, we find that the collective

J. P. Huang, L. Dong, K. W. Yu

We have derived the local electric field inside graded metal-dielectric composite films with weak nonlinearity analytically, which further yields the effective linear dielectric constant and third-order nonlinear susceptibility of the graded structures. As a result, the composition-dependent gradation can produce a broad resonant plasmon band in the optical

G. S. Uhrig, K. P. Schmidt, M. Grüninger

The magnetic excitations in the stripe phase of high-T_c superconductors are investigated in a model of spin ladders which are effectively coupled via charged stripes. Starting from the effective single-triplon model for the isolated spin ladder, the quasi-one-dimensional spin system can be described straightforwardly. Very good agreement is obtained with re

Peizhi Xu, Vladimir Chigrinov, Alexei D. Kiselev

We study dynamical optical response of a nematic liquid crystal cell that undergoes the splay-bend transition after applying the voltage across the cell. We formulate a simplified model that takes into account both the flexoelectric coupling and the surface rotational viscosity. The dynamic equations of the model were solved numerically to calculate temporal

V. A. Yurovsky

A problem of collisions of atoms with two-channel zero-range interaction in an atomic waveguide is solved by using of a renormalization procedure. A matching of the solution to a solution of the related one-dimensional problem leads to relation between the one-dimensional and three-dimensional scattering parameters. The scattering amplitude and bound states

K. E. Korreck, J. C. Raymond, T. H. Zurbuchen, P. Ghavamian

The appearance of the young supernova remnant SN1006 is dominated by emission from non-radiative shocks in the NE and NW regions. At X-ray energies the northeast shock exhibits predominantly nonthermal synchrotron emission, while the northwest shock exhibits a thermal spectrum. We present far ultraviolet spectra of the northeast (NE) and northwest (NW) porti

Noah Goodman

We study open books on three manifolds which are compatible with an overtwisted contact structure. We show that the existence of certain arcs, called sobering arcs, is a sufficient condition for an open book to be overtwisted, and is necessary up to stabilization by positive Hopf-bands. Using these techniques we prove that some open books arising as the boun

Andrea Banfi, Gavin P. Salam, Giulia Zanderighi

This article introduces definitions for a number of new event shapes and jet-rates in hadron-hadron dijet production. They are designed so as to be measurable in practice at the Tevatron and the LHC, and to be global so that they can be resummed with currently available techniques. We explain how to vary their sensitivity to beam fragmentation, limiting its

Andrea Banfi, Gavin P. Salam, Giulia Zanderighi

Next-to-leading logarithmic final-state resummed predictions have traditionally been calculated, manually, separately for each observable. In this article we derive NLL resummed results for generic observables. We highlight and discuss the conditions that the observable should satisfy for the approach to be valid, in particular continuous globalness and recu

Seikou Kato, Kei-Ichi Kondo

We show that the magnetic monopole promoted to the dyon due to the vacuum angle $θ$ resolves the U(1) problem in the sense that the dyon obtained in this way gives a dominant contribution to the topological susceptibility. For this purpose, we derive an Abelian-projected effective gauge theory written in terms of Abelian degrees of freedom, which is obtained

Athanasios Dedes, B. Todd Huffman

The discovery potential of the Tevatron CDF for the rare B-decay B_s --> mu^+ mu^- is analysed. We find that with an integrated luminosity of 2 fb^(-1), and using CDF as the example detector, a 5 sigma combined discovery reach of the Tevatron is possible if the Branching ratio for B_s --> mu^+ mu^- is (1.7 +- 0.46) \times 10^(-7). Such a possible signal for

Aleks Kleyn

Generalization of an idea may lead to very interesting result. Learning how torsion influences on tidal force reveals similarity between tidal equation for geodesic and the Killing equation of second type. The relationship between tidal acceleration, curvature and torsion gives an opportunity to measure torsion.

M. Auzinsh, D. Budker, D. F. Kimball, S. M. Rochester

In a recent letter [Auzinsh {\it{et. al.}} (physics/0403097)] we have analyzed the noise properties of an idealized atomic magnetometer that utilizes spin squeezing induced by a continuous quantum nondemolition measurement. Such a magnetometer measures spin precession of $N$ atomic spins by detecting optical rotation of far-detuned probe light. Here we consi

Dean Lee

Using effective field theory we prove inequalities for the correlations of two-nucleon operators in low-energy symmetric nuclear matter. For physical values of operator coefficients in the effective Lagrangian, the S = 1, I = 0 channel correlations must have the lowest energy and longest correlation length in the two-nucleon sector. This result is valid at n

Lei Chai, Dahui Wang, Jiawei Chen, Zengru Di

We construct a Markov process model to describe the evolution of labor division and its dynamical behavior is investigated by numerical simulations in detail. We have shown that under the mechanism of increasing returns, the division of labor will emerge from the initial homogenous distribution and with the change of parameters there are period-adding coarse

Sitabhra Sinha

According to the May-Wigner stability theorem, increasing the complexity of a network inevitably leads to its destabilization, such that a small perturbation will be able to disrupt the entire system. One of the principal arguments against this observation is that it is valid only for random networks, and therefore does not apply to real-world networks, whic

Pieter Moree

Let N_g(d) be the set of primes p such that the order of g modulo p is divisible by a prescribed integer d. Wiertelak showed that this set has a natural density and gave a rather involved explicit expression for it. Let N_g(d)(x) be the number of primes p<=x that are in N_g(d). A simple identity for N_g(d)(x) is established. It is used to derive a more compa

Alexander Schuster

It is shown that the formula for the Möbius pseudodistance for the annulus yields better estimates than previously known for the constant in the Bergman space maximum principle. A maximum principle for the Fock space is proved.

Andrei Zelevinsky

This is an expanded version of the notes for the two lectures at the 2004 International Mathematics Conference (Chonbuk National University, August 4-6, 2004). The first lecture discusses the origins of cluster algebras, with the focus on total positivity and geometry of double Bruhat cells in semisimple groups. The second lecture introduces cluster algebras

Lior Silberman, Akshay Venkatesh

We construct an equivariant microlocal lift for locally symmetric spaces. In other words, we demonstrate how to lift, in a ``semi-canonical&#39;&#39; fashion, limits of eigenfunction measures on locally symmetric spaces to Cartan-invariant measures on an appropriate bundle. The construction uses elementary features of the representation theory of semisimple

Masami Ohta

We study the structure of the Eisenstein component of Hida&#39;s ordinary p-adic Hecke algebra attached to modular forms, in connection with the companion forms in the space of modular forms (mod p). We show that such an algebra is a Gorenstein ring if certain space of modular forms (mod p) having companions is one-dimensional; and also give a numerical crit

Urs Frauenfelder, Viktor Ginzburg, Felix Schlenk

An action selector associates, in a suitable way, to each compactly supported Hamiltonian on a symplectic manifold an action value of the Hamiltonian. Action selectors are known to exist for a broad class of symplectic manifolds. We show how the existence of an action selector leads to sharp energy capacity inequalities between the Gromov width, the Hofer--Z

Michael I. Eides, Howard Grotch, Valery A. Shelyuto

We consider three-loop radiative-recoil corrections to hyperfine splitting in muonium generated by diagrams with one-loop radiative photon insertions both in the electron and muon lines. An analytic result for these nonlogarithmic corrections of order $α(Z^2α)(Zα)(m/M)\widetilde E_F$ is obtained. This result constitutes a next step in the implementation of t

G. V. Vereshchagin

Recently the mechanism was found which allows avoidance of the cosmological singularity within the semi-classical formulation of Loop Quantum Gravity. Numerical studies show that the presence of self-interaction potential of the scalar field allows generation of initial conditions for successful slow-roll inflation. In this paper qualitative analysis of dyna

Sergey P. Tsarev

We present a partial proof of van Hoeij-Abramov conjecture about the algorithmic possibility of computation of finite sums of rational functions. The theoretical results proved in this paper provide an algorithm for computation of a large class of sums $ S(n) = \sum_{k=0}^{n-1}R(k,n)$.

S. N. Dorogovtsev, J. F. F. Mendes

1. The birth of network science. 2. What are random networks? 3. Adjacency matrix. 4. Degree distribution. 5. What are simple networks? Classical random graphs. 6. Birth of the giant component. 7. Topology of the Web. 8.Uncorrelated networks. 9. What are small worlds? 10. Real networks are mesoscopic objects. 11. What are complex networks? 12. The configurat

Ignacio Trujillo, J. Alfonso L. Aguerri

Based on drizzled F606W and F814W images, we present quantitative structural parameters in the V-band rest-frame for all galaxies with z<1 and I_814(AB)<24.5 mag in the Hubble Deep Fields North and South. Our structural parameters are based on a two-component surface brightness distribution using a Sersic bulge and an exponential disc. Detailed simulations a

Jayant Murthy, David J. Sahnow

We have used observations taken under the FUSE S405/S505 channel realignment program to explore the diffuse FUV (1000 - 1200 Å) radiation field. Of the 71 independent locations in that program, we have observed a diffuse signal in 32, ranging in brightness from 1600 photons cm$^{-2}$ s$^{-1}$ sr$^{-1}$ Å$^{-1}$ to a maximum of $2.9 \times 10^5$ photons cm$^{

John T. Stocke, J. Michael Shull, Steven V. Penton

We describe our surveys of low column density Lyman-alpha absorbers [N(HI) = 10^(12.5-16.0) cm^-2], which show that the warm photoionized IGM contains 30% of all baryons at z < 0.1. This fraction is consistent with cosmological simulations, which also predict that an additional 20-40% of the baryons reside in hotter 10^(5-7) K gas, the warm-hot IGM (WHIM). T

Mark L. Henle, Philip A. Pincus

Multivalent counterions can induce an effective attraction between like-charged rodlike polyelectrolytes, leading to the formation of polelectrolyte bundles. In this paper, we calculate the equilibrium bundle size using a simple model in which the attraction between polyelectrolytes (assumed to be pairwise additive) is treated phenomenologically. If the coun

Cristian Lenart, Frank Sottile

We derive explicit Pieri-type multiplication formulas in the Grothendieck ring of a flag variety. These expand the product of an arbitrary Schubert class and a special Schubert class in the basis of Schubert classes. These special Schubert classes are indexed by a cycle which has either the form (k-p+1,k-p+2,...,k+1) or the form (k+p,k+p-1,...,k), and are pu

Shujun Li, Gonzalo Álvarez, Guanrong Chen, Xuanqin Mou

This paper studies the security of a secure communication scheme based on two discrete-time intermittently-chaotic systems synchronized via a common random driving signal. Some security defects of the scheme are revealed: 1) the key space can be remarkably reduced; 2) the decryption is insensitive to the mismatch of the secret key; 3) the key-generation proc

I. Yang, W. Kang, L. N. Pfeiffer, K. W. Baldwin

We report on quantum interference between a pair of counterpropagating quantum Hall edge states that are separated by a high quality tunnel barrier. Observed Aharonov-Bohm oscillations are analyzed in terms of resonant tunneling between coupled Luttinger liquids that creates bound electronic states between pairs of tunnel centers that act like interference s

Shi-Lin Zhu, C. M. Maekawa, B. R. Holstein, M. J. Ramsey-Musolf

We reformulate the analysis of nuclear parity-violation (PV) within the framework of effective field theory (EFT). To order Q, the PV nucleon-nucleon (NN) interaction depends on five a priori unknown constants that parameterize the leading-order, short-range four-nucleon operators. When pions are included as explicit degrees of freedom, the potential contain

Santiago G. Patiri, Juan E. Betancort-Rijo, Francisco Prada

We present a general analytical procedure for computing the number density of voids with radius above a given value within the context of gravitational formation of the large scale structure of the universe out of Gaussian initial conditions. To this end we develop an accurate (under generally satisfied conditions) extension of unconditional mass function to

Christoph Adami, Greg Ver Steeg

The fate of classical information incident on a quantum black hole has been the subject of an ongoing controversy in theoretical physics, because a calculation within the framework of semi-classical curved-space quantum field theory appears to show that the incident information is irretrievably lost, in contradiction to time-honored principles such as time-r

Michael Boylan-Kolchin, Chung-Pei Ma, Eliot Quataert

Anisotropic gravitational radiation from a coalescing black hole binary can impart a recoil velocity of up to several hundred km/s to the remnant black hole. We examine the effects of recoiling massive black holes on their host stellar bulges, both for holes that escape their host and those that return to the galactic center via dynamical friction. We show t

H. A. Dye, Louis H. Kauffman

The Witten-Reshetikhin-Turaev invariant of classical link diagrams is generalized to virtual link diagrams. This invariant is unchanged by the framed Reidemeister moves and the Kirby calculus. As a result, it is also an invariant of the 3-manifolds represented by the classical link diagrams. This generalization is used to demonstrate that there are virtual k

Hyun Min Lee, Antonios Papazoglou

We explore solutions of six dimensional gravity coupled to a non-linear sigma model, in the presence of co-dimension two branes. We investigate the compactifications induced by a spherical scalar manifold and analyze the conditions under which they are of finite volume and singularity free. We discuss the issue of single-valuedness of the scalar fields and p

Luc Bouten, Simon Edwards, V P Belavkin

Using results from quantum filtering theory and methods from classical control theory, we derive an optimal control strategy for an open two-level system (a qubit in interaction with the electromagnetic field) controlled by a laser. The aim is to optimally choose the laser&#39;s amplitude and phase in order to drive the system into a desired state. The Bellm

F. Ginelli, H. Hinrichsen, R. Livi, D. Mukamel

It is argued that some phase--transitions observed in models of non-equilibrium wetting phenomena are related to contact processes with long-range interactions. This is investigated by introducing a model where the activation rate of a site at the edge of an inactive island of length $\ell$ is $1+a\ell^{-σ}$. Mean--field analysis and numerical simulations in

Krzysztof M. Graczyk

Numerical results for the degree of polarization of τ^- produced in (CC) neutrino - nucleon Deep Inelastic Scattering (DIS) are presented. Calculations are done in the threshold region, where the τ^- scattered by the small angles and can be partially polarized. The cross sections and polarization are calculated by using the GRV98 parton distributions functio

A. N. St. J. Farley, P. D. D&#39;Eath

We study the quantum-mechanical decay of a Schwarzschild-like black hole into almost-flat space and weak radiation at a very late time, evaluating quantum amplitudes (not just probabilities) for transitions from initial to final states. No information is lost. The model contains gravity and a massless scalar field. The quantum amplitude to go from given init

John Ellis, N. E. Mavromatos, D. V. Nanopoulos, A. Sakharov

We present a specific model for cosmological inflation driven by the Liouville field in a non-critical supersymmetric string framework, in which the departure from criticality is due to open strings stretched between the two moving Type-II 5-branes. We use WMAP and other data on fluctuations in the cosmic microwave background to fix parameters of the model,

K. Stratford, R. Adhikari, I. Pagonabarraga, J. -C. Desplat

A new description of the binary fluid problem via the lattice Boltzmann method is presented which highlights the use of the moments in constructing two equilibrium distribution functions. This offers a number of benefits, including better isotropy, and a more natural route to the inclusion of multiple relaxation times for the binary fluid problem. In additio

Valerio Scarani, Hugues de Riedmatten, Ivan Marcikic, Hugo Zbinden

Correlated photons produced by spontaneous parametric down-conversion are an essential tool for quantum communication, especially suited for long-distance connections. To have a reasonable count rate after all the losses in the propagation and the filters needed to improve the coherence, it is convenient to increase the intensity of the laser that pumps the

P. Marecki, N. Szpak

We investigate (non-relativistic) atomic systems interacting with quantum electromagnetic field (QEF). The resulting model describes spontaneous emission of light from a two-level atom surrounded by various initial states of the QEF. We assume, that the quantum field interacts with the atom via the standard, minimal-coupling Hamiltonian, with the $A^2$ term

N. Bartolo, S. Matarrese, A. Riotto

We provide the gauge-invariant expression for large-scale cosmic microwave background temperature fluctuations at second-order in perturbation theory. It enables to unambiguously define the nonlinearity parameter f_NL which is used by experimental collaborations to pin down the level of Non-Gaussianity in the temperature fluctuations. Furthermore, it contain

A. Thiaville, Y. Nakatani, J. Miltat, Y Suzuki

In order to explain recent experiments reporting a motion of magnetic domain walls (DW) in nanowires carrying a current, we propose a modification of the spin transfer torque term in the Landau-Lifchitz-Gilbert equation. We show that it explains, with reasonable parameters, the measured DW velocities as well as the variation of DW propagation field under cur

Alessia Gualandris, Monica Colpi, Simon Portegies Zwart, Andrea Possenti

We explore the origin of the Galactic high latitude black hole X-ray binary XTE J1118+480, and in particular its birth location and the magnitude of the kick received by the black hole upon formation in the supernova explosion. We constrain the age of the companion to the black hole using stellar evolution calculations between 2 Gyr and 5 Gyr, making an orig

M. Francaviglia, M. Palese, E. Winterroth

By resorting to Noether&#39;s Second Theorem, we relate the generalized Bianchi identities for Lagrangian field theories on gauge-natural bundles with the kernel of the associated gauge-natural Jacobi morphism. A suitable definition of the curvature of gauge-natural variational principles can be consequently formulated in terms of the Hamiltonian connection

Akinori Isshiki, Kenichi Naito, Akira Ohnishi

We have introduced coherent state neutral pion into Antisymmetrized Molecular Dynamics. With the aid of coherent state technique, it becomes possible to calculate transition matrix elements of the pion field operator and to study excited states containing pions. For large pion-nucleon coupling fpiN > 1.6, pions have a finite expectation value and bring large

Francois Ghoulmie

This paper has been withdrawn by the author: it was a too preliminary version.

Eef van Beveren, George Rupp

We study bound states below threshold and resonances above threshold in the D0-K+ and Ds-eta systems, using a many-coupled-channel model for non-exotic meson-meson scattering applied to states with the quantum numbers of c-sbar quark-antiquark vector mesons. We fit the ground state at 2.112 GeV, whence the lowest resonances in D0-K+ come out at 2.61, 2.72, 3

Anita Sehat, Jonas Söderholm, Gunnar Björk, Pedro Espinoza

We show that any pure, two-mode, $N$-photon state with $N$ odd or equal to two can be transformed into an orthogonal state using only linear optics. According to a recently suggested definition of polarization degree, this implies that all such states are fully polarized. This is also found to be true for any pure, two-mode, energy eigenstate belonging to a

Krzysztof M. Graczyk

The quasielastic charged-current (CC) tau neutrino (antineutrino)-nucleus scattering is considered. The dependence of tau polarization on nuclear-structure effects is discussed in detail. The description of the nucleus is based on the Mean-Field Theory (MFT). The ground state of nucleus is described using the Relativistic Fermi Gas model (FG). The effective

Luca Sommovigo, Silvia Vaulá

We discuss the relation between standard N=2 supergravity with translational gauging and N=2 supergravities with scalar-tensor multiplets with massive tensors and Abelian electric charges. We point out that a symplectic covariant formulation of N=2 supergravity can be achieved just in the presence of tensor multiplets. As a consequence one can see that the f

Konstantin G. Boreskov, Alexander V. Turbiner, Juan C. Lopez Vieyra

Solvability of the rational quantum integrable systems related to exceptional root spaces $G_2, F_4$ is re-examined and for $E_{6,7,8}$ is established in the framework of a unified approach. It is shown the Hamiltonians take algebraic form being written in a certain Weyl-invariant variables. It is demonstrated that for each Hamiltonian the finite-dimensional

Jeff Greensite, Stefan Olejnik, Daniel Zwanziger

We show how the infinite color-Coulomb energy of color-charged states is related to enhanced density of near-zero modes of the Faddeev-Popov operator, and calculate this density numerically for both pure Yang-Mills and gauge-Higgs systems at zero temperature, and for pure gauge theory in the deconfined phase. We find that the enhancement of the eigenvalue de

Hal Tasaki

We consider a general one-dimensional tight-binding electron model which has a period $P$. For any filling factor $ν$ such that $Pν$ is non-integral, we prove that the model in the infinite volume limit has either a symmetry breaking or a unique ground state with gapless excitations. The proof is based on the idea of Yamanaka, Oshikawa and Affleck (cond-mat/

Z. G. Dai, E. W. Liang, D. Xu

An $E_{γ,{\rm jet}}\propto {E&#39;_p}^{1.5}$ relationship with a small scatter for current $γ$-ray burst (GRB) data was recently reported, where $E_{γ,{\rm jet}}$ is the beaming-corrected $γ$-ray energy and $E&#39;_p$ is the $νF_ν$ peak energy in the local observer frame. By considering this relationship for a sample of 12 GRBs with known redshift, peak ener

A. Goldenshluger, A. Tsybakov, A. Zeevi

We study nonparametric change-point estimation from indirect noisy observations. Focusing on the white noise convolution model, we consider two classes of functions that are smooth apart from the change-point. We establish lower bounds on the minimax risk in estimating the change-point and develop rate optimal estimation procedures. The results demonstrate t

Oriol Pujolas, Takahiro Tanaka

We study the quantum effects induced by bulk scalar fields in a model with a de Sitter (dS) brane in a flat bulk (the Vilenkin-Ipser-Sikivie model) in more than four dimensions. In ordinary dS space, it is well known that the stress tensor in the dS invariant vacuum for an effectively massless scalar ($m_\eff^2=m^2+ξ{\cal R}=0$ with ${\cal R}$ the Ricci scal

Maxime Imbeault

I briefly review CP violation in the B system, concentrating on B -> pi K decays. I discuss how to deal with electroweak-penguin contributions to these decays using flavour SU(3). With these, I show that the entire unitarity triangle can be extracted from measurements of B -> pi K decays. Finally, I examine the signals for new physics in these decays and the

Yu. M. Golubev, T. Yu. Golubeva, E. Giacobino

The full quantum-statistical theory of the Vertical-Cavity Surface-Emitting Laser (VCSEL) in the form of the Langevin equations is constructed for arbitrary relations between the frequency parameters. The same theoretical treatment as in Ref.[1,2] are used. For detailed analysis the theory is applied for lasers with equally living laser levels and on this ba

R. de la Madrid

The rigged Hilbert space of the algebra of the one-dimensional rectangular barrier potential is constructed. The one-dimensional rectangular potential provides another opportunity to show that the rigged Hilbert space fully accounts for Dirac&#39;s bra-ket formalism. The analogy between Dirac&#39;s formalism and Fourier methods is pointed out.

B. M. Fung, Vladimir L. Ermakov

The use of nuclear magnetic resonance (NMR) to carry out quantum information processing (QIP) often requires the preparation, transformation, and detection of pseudopure states. In our previous work, it was shown that the use of pairs of pseudopure states (POPS) as a basis for QIP is very convenient because of the simplicity in experimental execution. It is

S. Rebic, D. Vitali, C. Ottaviani, P. Tombesi

A novel effect of population transfer in a five-level system is analyzed. This population transfer effect is found to be a version of a Raman process, which is facilitated and assisted by coherence effects, acting to close other available decay channels.

S. Rebic, D. Vitali, C. Ottaviani, P. Tombesi

Large optical nonlinearities occurring in a coherently prepared atomic system are shown to produce phase shifts of order $π$. Such an effect may be observed in ultracold rubidium atoms where it could be feasibly exploited toward the realization of a polarization phase gate.

S. Rebic, D. Vitali, C. Ottaviani, P. Tombesi

We present the quantum theory of a polarization phase-gate that can be realized in a sample of ultracold rubidium atoms driven into a tripod configuration. The main advantages of this scheme are in its relative simplicity and inherent symmetry. It is shown that the conditional phase shifts of order $π$ can be attained.