September 2006 arXiv papers — page 2

Jorg Ruppert, Thorsten Renk

Nota bene: the numerical calculation underlying Version 1 of this reply and the original work Phys.Rev. C71:064903,2005 contains a basic numerical error (wrong factor in the self-energy formulas of Phys. Rev.C71:064903,2005). This renders the numerical results presented there and in Version 1 of the reply invalid and enforces a careful reinvestigation of Phy

C. D. Ott, H. Dimmelmeier, A. Marek, H. -T. Janka

We present results from the first 2D and 3D simulations of the collapse of rotating stellar iron cores in general relativity employing a finite-temperature equation of state and an approximate treatment of deleptonization during collapse. We compare fully nonlinear and conformally flat spacetime evolution methods and find that the conformally flat treatment

Levon Mardoyan, Armen Nersessian, Hayk Sarkisyan, Vahagn Yeghikyan

We consider the dipole transitions and the linear and quadratic Stark effect in the MICZ-Kepler system interpreting as a charge-dyon system. We show, that while the linear Stark effect in the ground state is proportional to azimuth quantum number(and to the sign of monopole number), the quadratic Stark effect in the ground state is independent on the signs o

Johan Martens

Motivated by Nekrasov's instanton counting, we discuss a method for calculating equivariant volumes of non-compact quotients in symplectic and hyper-Kähler geometry by means of the Jeffrey-Kirwan residue-formula of non-abelian localization. In order to overcome the non-compactness, we use varying symplectic cuts to reduce the problem to a compact setting

Michael Doran, Georg Robbers, Christof Wetterich

The first three years of observation of the Wilkinson Microwave Anisotropy Probe (WMAP) have provided the most precise data on the anisotropies of the cosmic microwave background (CMB) to date. We investigate the impact of these results and their combination with data from other astrophysical probes on cosmological models with a dynamical dark energy compone

Mohammad Rezaeian

We consider sensor scheduling as the optimal observability problem for partially observable Markov decision processes (POMDP). This model fits to the cases where a Markov process is observed by a single sensor which needs to be dynamically adjusted or by a set of sensors which are selected one at a time in a way that maximizes the information acquisition fro

Igor Bjelakovic, Holger Boche

We consider ergodic causal classical-quantum channels (cq-channels) which additionally have a decaying input memory. In the first part we develop some structural properties of ergodic cq-channels and provide equivalent conditions for ergodicity. In the second part we prove the coding theorem with weak converse for causal ergodic cq-channels with decaying inp

JLQCD Collaboration, N. Yamada, S. Aoki, H. Fukaya

We perform a systematic study of low-lying eigenmodes of $H_w$ with various gauge actions to find the optimal choice for dynamical overlap fermion simulations, with which one may achieve lower numerical cost for HMC and better locality property of the overlap kernel. For this purpose, our study is made with emphasis on the distribution of low-lying eigenvalu

Maria Bras-Amorós, Michael E. O'Sullivan

Analysis of the Berlekamp-Massey-Sakata algorithm for decoding one-point codes leads to two methods for improving code rate. One method, due to Feng and Rao, removes parity checks that may be recovered by their majority voting algorithm. The second method is to design the code to correct only those error vectors of a given weight that are also geometrically

Maria Bras-Amorós, Michael E. O'Sullivan

Garcia and Stichtenoth discovered two towers of function fields that meet the Drinfeld-Vlăduţ bound on the ratio of the number of points to the genus. For one of these towers, Garcia, Pellikaan and Torres derived a recursive description of the Weierstrass semigroups associated to a tower of points on the associated curves. In this article, a non-recursive de

M. J. Duff, S. Ferrara

In quantum information theory, it is well known that the tripartite entanglement of three qubits is described by the group [SL(2,C)]^3 and that the entanglement measure is given by Cayley's hyperdeterminant. This has provided an analogy with certain N=2 supersymmetric black holes in string theory, whose entropy is also given by the hyperdeterminant. In t

L. Feher, B. G. Pusztai

The reductions of the free geodesic motion on a non-compact simple Lie group G based on the $G_+ \times G_+$ symmetry given by left- and right multiplications for a maximal compact subgroup $G_+ \subset G$ are investigated. At generic values of the momentum map this leads to (new) spin Calogero type models. At some special values the `spin' degrees of fr

Maria Bras-Amorós, Michael E. O'Sullivan

We consider generalizations of Reed-Muller codes, toric codes, and codes from certain plane curves, such as those defined by norm and trace functions on finite fields. In each case we are interested in codes defined by evaluating arbitrary subsets of monomials, and in identifying when the dual codes are also obtained by evaluating monomials. We then move to

P. -M. Billangeon, F. Pierre, H. Bouchiat, R. Deblock

We measure the high-frequency emission of a single Cooper pair transistor(SCPT) in the regime where transport is only due to tunneling of Cooper pairs. This is achieved by coupling on-chip the SCPT to a superconductor-insulator-superconductor junction and by measuring the photon assisted tunneling current of quasiparticles across the junction. This technique

Sofian Teber

We consider one-dimensional (1D) spin-1/2 fermions in a clean quantum wire, with forward scattering interactions and a non-linear single-particle spectrum, $ξ_k = v|k| + k^2/2m$ where $v$ is the Fermi velocity and $1/m$ is the band-curvature. We calculate the dynamical structure factor (DSF) of the model at small wave-vector $q$ with the help of the bosoniza

A. Badertscher, P. Crivelli, W. Fetscher, U. Gendotti

The results of a new search for positronium decays into invisible final states are reported. Convincing detection of this decay mode would be a strong evid ence for new physics beyond the Standard Model (SM): for example the existence of extra--dimensions, of milli-charged particles, of new light gauge bosons or of mirror particles. Mirror matter could be a

Biswarup Mukhopadhyaya, Soumitra SenGupta, Raghavendra Srikanth

Supersymmetry offers a cold dark matter candidate, provided that lepton number is {\em not violated by an odd number of units}. On the other hand, lepton number violation by even (two) units gives us an attractive mechanism of neutrino mass generation. Here we offer an explanation of this, in a supergravity framework underlying a supersymmetric scenario, the

Daniel C. Cabra, Enrique F. Moreno, Adrian Tanasa

The definitions of para-Grassmann variables and q-oscillator algebras are recalled. Some new properties are given. We then introduce appropriate coherent states as well as their dual states. This allows us to obtain a formula for the trace of a operator expressed as a function of the creation and annihilation operators.

D. Bernard, G. Boffetta, A. Celani, G. Falkovich

We offer a new example of conformal invariance far from equilibrium -- the inverse cascade of Surface Quasi-Geostrophic (SQG) turbulence. We show that temperature isolines are statistically equivalent to curves that can be mapped into a one-dimensional Brownian walk (called Schramm-Loewner Evolution or SLE$_\kappa$). The diffusivity is close to $\kappa=4$, t

M. Blaauboer, R. L. de Visser

This paper addresses the question how to implement a desired two-qubit gate U using a given tunable two-qubit entangling interaction H_int. We present a general method which is based on the K_1 A K_2 decomposition of unitary matrices in SU(4) to calculate analytically the smallest number of two-qubit gates U_int [based on H_int] and single-qubit rotations, a

Tomoki Kawahira

According to an analogy to quasi-Fuchsian groups, we investigate topological and combinatorial structures of Lyubich and Minsky's affine and hyperbolic 3-laminations associated with the hyperbolic and parabolic quadratic maps. We begin by showing that hyperbolic rational maps in the same hyperbolic component have quasi-isometrically the same 3-lamination

Leonid, Kontorovich, Kavita Ramanan

The martingale method is used to establish concentration inequalities for a class of dependent random sequences on a countable state space, with the constants in the inequalities expressed in terms of certain mixing coefficients. Along the way, bounds are obtained on martingale differences associated with the random sequences, which may be of independent int

Shin-ichi Tadaki

Power-law fluctuation in observed Internet packet flow are discussed. The data is obtained by a multi router traffic grapher (MRTG) system for 9 months. The internet packet flow is analyzed using the detrended fluctuation analysis. By extracting the average daily trend, the data shows clear power-law fluctuations. The exponents of the fluctuation for the inc

Mattias T. Johnsson, Simon A. Haine

We describe a scheme for creating quadrature- and intensity-squeezed atom lasers that do not require squeezed light as an input. The beam becomes squeezed due to nonlinear interactions between the atoms in the beam in an analogue to optical Kerr squeezing. We develop an analytic model of the process which we compare to a detailed stochastic simulation of the

D. F. T. Mullamphy, G. Peach, V. Venturi, I. B. Whittingham

We report results for the Lorentzian profiles of the Li I, Na I and K I doublets and the Na I subordinate doublet broadened by helium perturbers for temperatures up to 3000 K They have been obtained from a fully quantum-mechanical close-coupling description of the colliding atoms, the Baranger theory of line shapes and new ab initio potentials for the alkali

Petr Glotov

In this paper we present the notions of trail (pseudo-)division, generalized subresultants and generalized subresultant algorithm.

David J. Jeffery, David Branch, E. Baron

Howell et al. have reported the discovery of SN Ia SN 2003fg (SNLS-03D3bb) and conclude that SN 2003fg is very likely a super-Chandrasekhar-mass SN Ia perhaps with a mass of order 2 solar masses. Their work is the first strong evidence that has been presented for a super-Chandrasekhar SN Ia. We have performed an analysis of the SN 2003fg data using the Yoon

Frank Sottile

Understanding, finding, or even deciding on the existence of real solutions to a system of equations is a very difficult problem with many applications. While it is hopeless to expect much in general, we know a surprising amount about these questions for systems which possess additional structure. Particularly fruitful--both for information on real solutions

Dan Barbasch

This paper gives a complete classification of the unitary irreducible spherical representations of split real and p-adic groups. The results were obtained around 2000, the changes to the new version are expository.

A. O. Lyakhov, C. Bruder

We propose a method to improve quantum state transfer in transmission lines. The idea is to localize the information on the last qubit of a transmission line, by dynamically varying the coupling constants between the first and the last pair of qubits. The fidelity of state transfer is higher then in a chain with fixed coupling constants. The effect is stable

Paolo Amore, Francisco M. Fernandez

We apply the method of Dalgarno and Lewis to scattering states and discuss the choice of the unperturbed model in order to have a convergent perturbation series for the phase shift.

Harun Egrifes, Ramazan Sever

The one-dimensional Klein-Gordon equation is solved for the PT-symmetric generalized Hulthen potential in the scalar coupling scheme. The relativistic bound-state energy spectrum and the corresponding wave functions are obtained by using the Nikiforov-Uvarov method which is based on solving the second-order linear differential equations by reduction to a gen

Sara Felloni, Giuliano Strini

The aim of this paper is to introduce a new graphic representation of quantum states by means of a specific application: the analysis of two models of quantum copying machines. The graphic representation by diagrams of states offers a clear and detailed visualization of quantum information's flow during the unitary evolution of not too complex systems. T

M. Riebe, K. Kim, P. Schindler, T. Monz

A crucial building block for quantum information processing with trapped ions is a controlled-NOT quantum gate. In this paper, two different sequences of laser pulses implementing such a gate operation are analyzed using quantum process tomography. Fidelities of up to 92.6(6)% are achieved for single gate operations and up to 83.4(8)% for two concatenated ga

Indrani Chattopadhyay, Debasis Sarkar

In this work we show that the most general class of anti-unitary operators are nonphysical in nature through the existence of incomparable pure bipartite entangled states. It is also shown that a large class of inner-product-preserving operations defined only on the three qubits having spin-directions along x, y and z are impossible. If we perform such an op

P. M. Leung, T. C. Ralph

We have modelled the Zeno effect Control-Sign gate of Franson et al (PRA 70, 062302, 2004) and shown that high two-photon to one-photon absorption ratios, $κ$, are needed for high fidelity free standing operation. Hence we instead employ this gate for cluster state fusion, where the requirement for $κ$ is less restrictive. With the help of partially offline

Feng Lu, Dan C. Marinescu

Grover's search algorithm can be applied to a wide range of problems; even problems not generally regarded as searching problems, can be reformulated to take advantage of quantum parallelism and entanglement, and lead to algorithms which show a square root speedup over their classical counterparts. In this paper, we discuss a systematic way to formulate

Michael Baake, Uwe Grimm, Harald Jockusch

A simple weakly frequency dependent model for the dynamics of a population with a finite number of types is proposed, based upon an advantage of being rare. In the infinite population limit, this model gives rise to a non-smooth dynamical system that reaches its globally stable equilibrium in finite time. This dynamical system is sufficiently simple to permi

Luis Enrique Correa da Rocha, Luciano da Fontoura Costa

Complex networks have established themselves along the last years as being particularly suitable and flexible for representing and modeling several complex natural and human-made systems. At the same time in which the structural intricacies of such networks are being revealed and understood, efforts have also been directed at investigating how such connectiv

Lennon O Naraigh, Jean-Luc Thiffeault

The advective Cahn-Hilliard equation describes the competing processes of stirring and separation in a two-phase fluid. Intuition suggests that bubbles will form on a certain scale, and previous studies of Cahn-Hilliard dynamics seem to suggest the presence of one dominant length scale. However, the Cahn-Hilliard phase-separation mechanism contains a hyperdi

Sebastien Forget, Clement Faugeras, Jean Yves Bengloan, Michel Calligaro

High performance of InP-based quantum cascade lasers emitting at $λ$ ~ 9$μ$m are reported. Thick electroplated gold layer was deposited on top of the laser to improve heat dissipation. With one facet high reflection coated, the devices produce a maximum output power of 175mW at 40% duty cycle at room temperature and continuous-wave operation up to 278K.

Louis Gostiaux, Henri Didelle, Stephane Mercier, Thierry Dauxois

We present a new kind of generator of internal waves which has been designed for three purposes. First, the oscillating boundary conditions force the fluid particles to travel in the preferred direction of the wave ray, hence reducing the mixing due to forcing. Secondly, only one ray tube is produced so that all of the energy is in the beam of interest. Thir

Sebastien Forget, Frederic Druon, Francois Balembois, Patrick Georges

the realization of high repetition rate passively Q-switched monolithic microlaser is a challenge since a decade. To achieve this goal, we report here on the first passively Q-switched diode-pumped microchip laser based on the association of a Nd:GdVO4 crystal and a Cr4+:YAG saturable absorber. The monolithic design consists of 1 mm long 1% doped Nd:GdVO4 op

Burra G. Sidharth

We argue that a non commutative geometry at the Compton scale is at the root of mass, Quantum Mechanical spin and QCD and electromagnetic interactions. It also leads to a reconciliation of linearized General Relativity and Quantum Theory.

Chien-chih Chen, Chih-Yuan Tseng, Jia-Jyun Dong

We propose a new data analyzing scheme, the method of minimum entropy analysis (MEA), in this paper. New MEA provides a quantitative criterion to select relevant variables for modeling the physical system interested. Such method can be easily extended to various geophysical/geological data analysis, where many relevant or irrelevant available measurements ma

Chih-Yuan Tseng, Chien-Chih CHen

In this work, we present a minimum entropy analysis scheme for variable selection and preliminary data analysis. The variable selection can be achieved by the increasing preference of variables. We show such a preference to has a unqiue form, which is given by the entropy of models associated with variables. Evaluating the entropy provides a complete ranking

C. B. Compean, M. Kirchbach

A common quark potential that captures the essential traits of the QCD quark-gluon dynamics is expected to (i) interpolate between a Coulomb-like potential (associated with one-gluon exchange) and the infinite wall potential (associated with trapped but asymptotically free quarks), (ii) reproduce in the intermediary region the linear confinement potential (a

T. Papenbrock, Anirban Bhattacharyya

We consider the pairing Hamiltonian and systematically construct its density functional in the strong-coupling limit and in the limit of large particle number. In the former limit, the functional is an expansion into central moments of occupation numbers. In the latter limit, the functional is known from BCS theory. Both functionals are nonlocal in structure

Jorg Ruppert, Thorsten Renk

The NA60 experiment has studied low-mass muon pair production in In-In collisions at $158 {\rm AGeV}$ with unprecedented precision. With these results there is hope that the in-medium modifications of the vector meson spectral function can be constrained more thoroughly than before. We investigate in particular what can be learned about collisional broadenin

M. Di Toro, V. Baran, M. Colonna, G. Ferini

Heavy Ion Collisions (HIC) represent a unique tool to probe the in-medium nuclear interaction in regions away from saturation and at high nucleon momenta. In this report we present a selection of reaction observables particularly sensitive to the isovector part of the interaction, i.e. to the symmetry term of the nuclear Equation of State (EoS) At low energi

E. Ruiz Arriola, M. Pavon Valderrama

The renormalization of singular chiral potentials as applied to NN scattering and the structure of the deuteron is discussed. It is shown how zero range theories may be implemented non-perturbatively as constrained from known long range NN forces.

Ivo Slaus

Few-body research history, achievements, current development and challenges are presented.

Jason Glyndwr Ulery

Two-particle azimuthal correlations reveal broadened and softened away-side correlations. Several different physics mechanisms are possible: large angle gluon radiation, deflected jets, and conical flow or Cerenkov radiation. Three-particle correlations are investigated to try to discriminate these mechanisms. We present results on 3-particle azimuthal corre

K. Yako, H. Sagawa, H. Sakai

Charge exchange spin-dipole (SD) excitations of 90Zr are studied by the 90Zr(p,n) and 90Zr(n,p) reactions at 300 MeV. A multipole decomposition technique is employed to obtain the SD strength distributions in the cross section spectra. For the first time, a model-independent SD sum rule value is obtained: 148+/-12 fm^2. The neutron skin thickness of 90Zr is

EX Collaboration, E. Geraci, U. Abbondanno, L. Bardelli

Symmetry energy is a key quantity in the study of the equation of state of asymmetric nuclear matter. Heavy ion collisions at low and intermediate energies, performed at Laboratori Nazionali di Legnaro and Laboratori Nazionali del Sud, can be used to extract information on the symmetry energy coefficient Csym, which is currently poorly known but relevant bot

A. Ya. Maltsev

We consider the deformation of the Whitham system for the non-linear Klein-Gordon equation having the Lorentz-invariant form. Using the Lagrangian formalism of the initial system we obtain the first non-trivial correction to the Whitham system in the Lorentz-invariant approach.

B. B. Baizakov, G. Filatrella, B. A. Malomed

We show the existence of steadily moving solitary pulses (SPs) in the complex Ginzburg-Landau (CGL) equation, which includes the cubic-quintic (CQ) nonlinearity and a conservative linear driving term, whose amplitude is a standing wave with wavenumber $k$ and frequency $ω$, the motion of the SPs being possible at velocities $\pm ω/k$, which provide locking t

Christian Gerard, Christian Jaekel

The relativistic KMS condition introduced by Bros and Buchholz provides a link between quantum statistical mechanics and quantum field theory. We show that for the $P(ϕ)_2$ model at positive temperature, the two point function for fields satisfies the relativistic KMS condition.

Paolo Amore, Hakan Ciftci, Francisco M. Fernandez

We discuss alternative iteration methods for differential equations. We provide a convergence proof for exactly solvable examples and show more convenient formulas for nontrivial problems.

Fumio Hiroshima, Itaru Sasaki

An enhanced binding of an $N$-particle system interacting through a scalar bose field is investigated, where $N\geq 2$. It is not assumed that this system has a ground state for a zero coupling. It is shown, however, that there exists a ground state for a sufficiently large values of coupling constants. When the coupling constant is sufficiently large, $N$ p

Yun-Su Kim

We study modularity of the lattice Lat $(T)$ of closed invariant subspaces for a $C_0$-operator $T$ and find a condition such that Lat $(T)$ is a modular. Furthermore, we provide a quasiaffinity preserving modularity.

Yun-Su Kim

We study $C_{0}$-operators relative to a multiply connected domain using a substitute of the characteristic function. This method allows us to prove certain relations between the Jordan model of an operator and that of its restriction to an invariant subspace.

Han Peters, Liz Raquel Vivas, Erlend Fornæss Wold

We study toplogical properties of attracting sets for automorphisms of $\mathbb{C}^k$. Our main result is that a generic volume preserving automorphism has a hyperbolic fixed point with a dense stable manifold. We prove the same result for volume preserving maps tangent to the identity. On the other hand, we show that an attracting set can only contain a nei

Matilde N. Lalin

There are many examples of several-variable polynomials whose Mahler measure is expressed in terms of special values of polylogarithms. These examples are expected to be related to computations of regulators, as observed by Deninger, and later Rodriguez-Villegas, and Maillot. While Rodriguez-Villegas made this relationship explicit for the two variable case,

Jakob G. Heller, Nikolai Neumaier, Stefan Waldmann

Locally noncommutative spacetimes provide a refined notion of noncommutative spacetimes where the noncommutativity is present only for small distances. Here we discuss a non-perturbative approach based on Rieffel's strict deformation quantization. To this end, we extend the usual C*-algebraic results to a pro-C*-algebraic framework.

Terence Tao

The endpoint Strichartz estimate $\| e^{itΔ} f \|_{L^2_t L^\infty_x(\R \times \R^2)} \lesssim \|f\|_{L^2_x(\R^2)}$ is known to be false by the work of Montgomery-Smith, despite being only ``logarithmically far'' from being true in some sense. In this short note we show that (in sharp constrast to the $L^p_{t,x}$ Strichartz estimates) the situation is

Giovanni Felder

Andrei Okounkov received the Fields Medal at the ICM 2006 in Madrid "for his contributions bridging probability, representation theory and algebraic geometry". This is a brief account of his work.

Miklos Bona

Let $S$ be a finite set of positive integers with largest element $m$. Let us randomly select a composition $a$ of the integer $n$ with parts in $S$, and let $m(a)$ be the multiplicity of $m$ as a part of $a$. Let $0\leq r<q$ be integers, with $q\geq 2$, and let $p_{n,r}$ be the probability that $m(a)$ is congruent to $r$ modulo $q$. We show that if $S$ sati

Bernhard Köck, David Singerman

We develop a Belyi type theory that applies to Klein surfaces, i.e. (possibly non-orientable) surfaces with boundary which carry a dianalytic structure. In particular we extend Belyi&#39;s famous theorem from Riemann surfaces to Klein surfaces.

Annette Werner

Let G be a connected semisimple group over a non-Archimedean local field. For every faithful, geometrically irreducible linear representation of G we define a compactification of the associated Bruhat-Tits building X(G). This yields a finite family of compactifications of X(G) which contains the polyhedral compactification. Moreover, this family can be regar

M. T. Barlow, R. F. Bass, Z. -Q. Chen., M. Kassmann

We consider the symmetric non-local Dirichlet form $(E, F)$ given by \[ E (f,f)=\int_{R^d} \int_{R^d} (f(y)-f(x))^2 J(x,y) dx dy \] with $F$ the closure of the set of $C^1$ functions on $R^d$ with compact support with respect to $E_1$, where $E_1 (f, f):=E (f, f)+\int_{R^d} f(x)^2 dx$, and where the jump kernel $J$ satisfies \[ κ_1|y-x|^{-d-α} \leq J(x,y) \l

Anna de Mier

A flag matroid can be viewed as a chain of matroids linked by quotients. Flag matroids, of which relatively few interesting families have previously been known, are a particular class of Coxeter matroids. In this paper we give a family of flag matroids arising from an enumeration problem that is a generalization of the tennis ball problem. These flag matroid

Bert van Geemen

The endomorphism algebra of a K3 type Hodge structure is a totally real field or a CM field. In this paper we give a low brow introduction to the case of a totally real field. We give existence results for the Hodge structures, for their polarizations and for certain K3 surfaces. We consider the Kuga Satake variety of these Hodge structures and we discuss so

E. Aguirre, V. Fernández, J. Lafuente

Physical reasons suggested in \cite{Ha-Ha} for the \emph{Quantum Gravity Problem} lead us to study \emph{type-changing metrics} on a manifold. The most interesting cases are \emph{Transverse Riemann-Lorentz Manifolds}. Here we study the conformal geometry of such manifolds.

Vivina Barutello, Simone Secchi

We study a singular Hamiltonian system with an $\al$-homogeneous potential that contains, as a particular case, the classical $N$--body problem. We introduce a variational Morse--like index for a class of collision solutions and, using the asymptotic estimates near collisions, we prove the non-minimality of some special classes of colliding trajectories unde

E. J. Janse van Rensburg, T. Prellberg, A. Rechnitzer

The enumeration of lattice paths in wedges poses unique mathematical challenges. These models are not translationally invariant, and the absence of this symmetry complicates both the derivation of a functional recurrence for the generating function, and solving for it. In this paper we consider a model of partially directed walks from the origin in the squar

Yi-Zhi Huang, James Lepowsky, Lin Zhang

We generalize the tensor product theory for modules for a vertex operator algebra previously developed in a series of papers by the first two authors to suitable module categories for a ``conformal vertex algebra&#39;&#39; or even more generally, for a &#34;Möbius vertex algebra.&#39;&#39; We do not require the module categories to be semisimple, and we acco

Adam S. Sikora, Bruce W. Westbury

We develop a theory of confluence of graphs. We describe an algorithm for proving that a given system of reduction rules for abstract graphs and graphs in surfaces is locally confluent. We apply this algorithm to show that each simple Lie algebra of rank at most 2, gives rise to a confluent system of reduction rules of graphs (via Kuperberg&#39;s spiders) in

Mingxing Zhang, Ruifeng Qui, Yannan Li

Let $M$ be a simple 3-manifold such that one component of $\partial M$, say $F$, has genus at least two. For a slope $α$ on $F$, we denote by $M(α)$ the manifold obtained by attaching a 2-handle to $M$ along a regular neighborhood of $α$ on $F$. If $M(α)$ is reducible, then $α$ is called a reducing slope. In this paper, we shall prove that the distance betwe

Nelson Faustino, Uwe Kaehler

We establish the basis of a discrete function theory starting with a Fischer decomposition for difference Dirac operators. Discrete versions of homogeneous polynomials, Euler and Gamma operators are obtained. As a consequence we obtain a Fischer decomposition for the discrete Laplacian.

Benoit Bertrand, Erwan Brugalle

A cumbersome hypothesis for Viro patchworking of real algebraic curves is the convexity of the given subdivision. It is an open question in general to know whether the convexity is necessary. In the case of trigonal curves we interpret Viro method in terms of dessins d&#39;enfants. Gluing the dessins d&#39;enfants in a coherent way we prove that no convexity

L. Vaksman

This volume contains a mildly expanded version of lectures and talks at seminars and conferences, as well as review papers on subjects listed in the title of the volume. A great deal of these texts have already been published or sent to press. However, the only way to provide a good exposition of the field we are interested in is to collect all of those pape

Satabhisa Dasgupta, Tathagata Dasgupta

In hep-th/0311177, the Large $N$ renormalization group (RG) flows of a modified matrix quantum mechanics on a circle, capable of capturing effects of nonsingets, were shown to have fixed points with negative specific heat. The corresponding rescaling equation of the compactified matter field with respect to the RG scale, identified with the Liouville directi

R. N. Ghalati, N. Kiriushcheva, S. V. Kuzmin, D. G. C. McKeon

The first order form of a three dimensional U(1) gauge theory in which a gauge invariant mass term appears is analyzed using the Dirac procedure. The form of the gauge transformation which leaves the action invariant is derived from the constraints present.

N. Kiriushcheva, S. V. Kuzmin, D. G. C. McKeon

Using the Dirac constraint formalism, we examine the canonical structure of the Einstein-Hilbert action $S_d = \frac{1}{16πG} \int d^dx \sqrt{-g} R$, treating the metric $g_{αβ}$ and the symmetric affine connection $Γ_{μν}^λ$ as independent variables. For $d > 2$ tertiary constraints naturally arise; if these are all first class, there are $d(d-3)$ independe

S. A. Gadjiev, R. G. Jafarov

The Dirac method of canonical quantization of theories with second class constraints has to be modified if the constraints depend on time explicitly. A solution of the problem was given by Gitman and Tyutin. In the present work we propose an independent way to derive the rules of quantization for these systems, starting from physical equivalent theory with t

Ben Craps, Oleg Evnin, Shin Nakamura

One-loop string scattering amplitudes computed using the standard D0-brane conformal field theory (CFT) suffer from infrared divergences associated with recoil. A systematic framework to take recoil into account is the worldline formalism, where fixed boundary conditions are replaced by dynamical D0-brane worldlines. We show that, in the worldline formalism,

Filipe R. Joaquim, Anna Rossi

We discuss a GUT realization of the supersymmetric triplet seesaw mechanism(recently proposed by us in hep-ph/0604083 and further analyzed in hep-ph/0607298) where the exchange of the heavy triplet states generates both neutrino masses and soft SUSY breaking terms.

A. Bramon, G. Garbarino, B. H. Hiesmayr

Neutral kaons are unique quantum systems to show some of the most puzzling peculiarities of quantum mechanics. Here we focus on a quantitative version of Bohr&#39;s complementary principle and on quantum marking and eraser concepts. In detail we show that neutral kaons (1) are kind of double slit devices encapsulating Bohr&#39;s complementarity principle in

G. Balossini, C. M. Carloni Calame, G. Montagna, O. Nicrosini

We report on a high-precision calculation of the Bhabha process in QED, of interest for precise luminosity determination of low-energy electron-positron colliders. The calculation is based on the matching of exact next-to-leading order corrections with a Parton Shower algorithm. The structure of the algorithm (implemented in an improved version of the event

V. A. Khoze, A. D. Martin, M. G. Ryskin

The triple-Pomeron coupling lies at the heart of the predictions for high energy diffractive processes. We explain why the existing determinations, which use single-particle inclusive hadronic data a+b -> a+Y, underestimate the value of the bare coupling, due to the neglect of soft rescattering which populates the rapidity gaps. We describe how data for the

Cyrille Marquet

In the context of both inclusive and diffractive deep inelastic scattering, we derive the first phenomenological consequences of the inclusion of Pomeron loops in the QCD evolution equations towards high energy. We discuss the transition between the well-known geometric scaling regime and the new diffusive scaling, that emerges for sufficiently high energies

D. Aristizabal Sierra, M. Hirsch

The smallness of the observed neutrino masses might have a radiative origin. Here we revisit a specific two-loop model of neutrino mass, independently proposed by Babu and Zee. We point out that current constraints from neutrino data can be used to derive strict lower limits on the branching ratio of flavour changing charged lepton decays, such as $μ\to e γ$

S. Gieseke, D. Grellscheid, K. Hamilton, A. Ribon

A new release of the Monte Carlo program Herwig++ (version 2.0) is now available. This is the first version of the program which can be used for hadron-hadron physics and includes the full simulation of both initial- and final-state QCD radiation.

N. Yu. Agafonova, M. Aglietta, P. Antonioli, G. Bari

The LVD detector, located in the INFN Gran Sasso National Laboratory (Italy), studies supernova neutrinos through the interactions with protons and carbon nuclei in the liquid scintillator and interactions with the iron nuclei of the support structure. We investigate the effect of neutrino oscillations in the signal expected in the LVD detector. The MSW effe

Abdou M. Abdel-Rehim, Randy Lewis, Robert G. Petry, R. M. Woloshyn

The effect of using smeared sink operators on the hadron spectrum is studied for quenched twisted mass lattice QCD with up, down, and strange quarks. Gaussian smearing is used for quark fields, and stout link smearing for gauge fields. Smeared correlators are found to be dominated by the ground state with a small contribution from excited states, leading to

Claude Bernard, Maarten Golterman, Yigal Shamir

We investigate the properties of staggered-fermion lattice QCD in which the fourth root of the fermion determinant is taken. We show that this theory is non-local at non-zero lattice spacing $a$, and that the non-locality is caused by the breaking of taste symmetry at $a\ne 0$. We then present a renormalization-group based argument that the theory restores t

Francesco Di Renzo, Vincenzo Miccio, Luigi Scorzato, Christian Torrero

By making use of Numerical Stochastic Perturbation Theory (NSPT) we can compute renormalization constants for Lattice QCD to high orders, e.g. three or four loops for quark bilinears. We report on the status of our computations, which provide several results for Wilson quarks and in particular (values and/or ratios of) Z_V, Z_A, Z_S, Z_P. Results are given f

K. Splittorff, J. J. M. Verbaarschot

We show that in the microscopic domain of QCD (also known as the $ε$-domain) at nonzero chemical potential the average phase factor of the fermion determinant is nonzero for $μ< m_π/2$ and is exponentially suppressed for larger values of the chemical potential. This follows from the chiral Lagrangian that describes the low-energy limit of the expectation val

S. Ejiri, T. Hatsuda, N. Ishii, Y. Maezawa

The QCD thermodynamics on the lattice provides fundamental theoretical grounds to analyze the various experimental data in relativistic heavy ion collisions. So far, most of the numerical simulations on the lattice have been performed by using the staggered-type fermion actions. Therefore it is important to carry out studies using different fermion formulati