December 2006 arXiv papers — page 5

Takashi Hotta

We investigate how Kondo phenomenon occurs in the Anderson model dynamically coupled with local Jahn-Teller phonons. It is found that the total angular moment composed of electron pseudo-spin and phonon angular moments is screened by conduction electrons. Namely, phonon degrees of freedom essentially contribute to the formation of singlet ground state. A cha

R. J. Sault, C. Engel, Imke de Pater

We present a technique for creating a longitude-resolved image of Jupiter's thermal radio emission. The technique has been applied to VLA data taken on 25 January 1996 at a wavelength of 2 cm. A comparison with infrared data shows a good correlation between radio hot spots and the 5 micron hot spots seen on IRTF images. The brightest spot on the radio im

David Kirkman, David Tytler, Dan Lubin, Jane Charlton

We measure the amount of absorption in the Lyman-alpha forest at 0 < z < 1.6 in HST FOS spectra of 74 QSOs. At 0 < z < 1.6 we find that 79% of the absorption is from the low density intergalactic medium, 12% from metals and 9% from the strong H I lines, nearly identical to the percentages (78, 15 and 7) that we measured independently at z=2 from spectra take

K. E. Korreck, T. H. Zurbuchen, S. T. Lepri, J. M . Raines

Shock heating and particle acceleration processes are some of the most fundamental physical phenomena of plasma physics with countless applications in laboratory physics, space physics, and astrophysics. This study is motivated by previous observations of non-thermal heating of heavy ions in astrophysical shocks (Korreck et al. 2004). Here, we focus on shock

P. Abolmasov, S. Fabrika, O. Sholukhova, V. Afanasiev

Here we present the results of panoramic and long-slit observations of eight ULX nebular counterparts held with the 6m SAO telescope. In two ULXNe we detected for the first time signatures of high excitation ([OIII]5007 / Hβ> 5). Two of the ULXs were identified with young (T ~ 5-10 Myr) massive star clusters. Four of the eight ULX Nebulae (ULXNe) show bright

F. J. Cao

We compute the primordial scalar, vector and tensor metric perturbations arising from quantum field inflation. Quantum field inflation takes into account the nonperturbative quantum dynamics of the inflaton consistently coupled to the dynamics of the (classical) cosmological metric. For chaotic inflation, the quantum treatment avoids the unnatural requiremen

Stephen R. Kane, Jian Ge

Many of the planets discovered via the radial velocity technique are hot Jupiters in 3-5 day orbits with ~10$% chance of transiting their parent star. However, radial velocity surveys for extra-solar planets generally require substantial amounts of large telescope time in order to monitor a sufficient number of stars due to the single-object capabilities of

A. Gomboc, C. Guidorzi, C. G. Mundell, A. Melandri

We summarise recent deep, rapid GRB follow-up observations using the RoboNet-1.0 network which comprises three fully-robotic 2-m telescopes, the Liverpool Telescope and the Faulkes Telescopes North and South. Observations begin automatically within minutes of receipt of a GRB alert and may continue for hours or days to provide well-sampled multi-colour light

O. Kochukhov, T. Ryabchikova, W. W. Weiss, J. D. Landstreet

We have carried out the first survey of the pulsational line profile variability in rapidly oscillating Ap (roAp) stars. We analysed high signal-to-noise time-series observations of ten sharp-lined roAp stars obtained with the high-resolution spectrographs attached to the VLT and CFHT telescopes. We investigated in detail the variations of Pr III, Nd II, Nd

Assaf Sternberg, Fabio Pizzolato, Noam Soker

We conduct two-dimensional hydrodynamical simulations of jets expanding in the intra-cluster medium (ICM). We find that for a fat, i.e. more or less spherical, bubble attached to the center to be formed the jet should have high momentum flux and a large opening angle. Typically, the half opening angle should be >50 degrees, and the large momentum flux requir

R. J. Sault, P. J. Teuben, M. C. H. Wright

Miriad is a radio interferometry data-reduction package, designed for taking raw data through to the image analysis stage. The Miriad project, begun in 1988, is now middle-aged. With the wisdom of hindsight, we review design decisions and some of Miriad&#39;s characteristics.

R. F. Griffin, H. M. J. Boffin

The three objects have been identified as members of the recently recognized class of Gamma Doradus stars, which exhibit multi-periodic photometric variations that are thought to arise from non-radial pulsation. The particular objects treated here also prove to be spectroscopic binaries, for which we provide reliable orbits. The radial velocities exhibit unu

Jing-Mei Qiu, Long-Long Feng, Chi-Wang Shu, Li-Zhi Fang

We develop a numerical solver for radiative transfer problems based on the weighted essentially nonoscillatory (WENO) scheme modified with anti-diffusive flux corrections, in order to solve the temperature and ionization profiles around a point source of photons in the reionization epoch. Algorithms for such simulation must be able to handle the following tw

Jun Kataoka, James N. Reeves, Kazushi Iwasawa, Alex G. Markowitz

Broad line radio galaxies (BLRGs) are a rare type of radio-loud AGN, in which the broad optical permitted emission lines have been detected in addition to the extended jet emission. Here we report on deep (40ksec x4) observations of the bright BLRG 3C~120 using Suzaku. The observations were spaced a week apart, and sample a range of continuum fluxes. An exce

M. Mayer, J. E. Pringle

We present an extension of the King et al. (2004) model for the flickering of black hole accretion discs by taking proper account for the thermal properties of the disc. First we develop a one-dimensional, vertically averaged, one-zone model for an optically thick accretion disc and study the temporal evolution. This limits the current model to the so-called

M. Mayer, J. E. Pringle

We present time-dependent simulations of a two-phase accretion flow around a black hole. The accretion flow initially is composed of an optically thick and cool disc close to the midplane, while on top and below the disc there is a hot and optically thin corona. We consider several interaction mechanisms as heating of the disc by the corona and Compton cooli

V. K. Onemli

I elaborate on my prediction that an indirect detection of cold dark matter (CDM) may be possible by observing the gravitational lensing effects of the CDM cusp caustics at cosmological distances. Cusps in the distribution of CDM are plentiful once density perturbations enter the nonlinear regime of structure formation. Caustic ring model of galactic halo fo

Ken-ya Watarai

In a previous paper, we described new analytic formulae for optically-thick supercritical accretion flows (Watarai 2006, hereafter paper 1). Here we present analytic formulae for optically-thin one-temperature accretion flows including the advection-dominated regime, using the ``semi-iterative&#39;&#39; method described in paper 1. Our analytic formulae have

Juan Blandon, Viatcheslav Kokoouline, Francoise Masnou-Seeuws

We developed a method to calculate positions and widths of three-body resonances. The method combines the hyperspherical adiabatic approach, slow variable discretization method (Tolstikhin et al., J. Phys. B: At. Mol. Opt. Phys. 29, L389 (1996)), and a complex absorbing potential. The method can be used to obtain resonances having short-range or long-range w

Peter R Law, Yasuo Matsushita

A four-dimensional Walker geometry is a four-dimensional manifold M with a neutral metric g and a parallel distribution of totally null two-planes. This distribution has a natural characterization as a projective spinor field subject to a certain constraint. Spinors therefore provide a natural tool for studying Walker geometry, which we exploit to draw toget

L. Bary-Soroker

We prove Dirichlet&#39;s theorem for polynomial rings: Let F be a pseudo algebraically closed field. Then for all relatively prime polynomials a(X), b(X)\in F[X] and for every sufficiently large positive integer n there exist infinitely many polynomials c(X)\in F[X] such that a(X) + b(X)c(X) is irreducible of degree n, provided that F has a separable extensi

Wolfhard Janke, Adriaan M. J. Schakel

In these notes, the application of Feynman&#39;s sum-over-paths approach to thermal phase transitions is discussed. The paradigm of such a spacetime approach to critical phenomena is provided by the high-temperature expansion of spin models. This expansion, known as the hopping expansion in the context of lattice field theory, yields a geometric description

G. Brodin, M. Marklund

Starting from the non-relativistic Pauli description of spin-1/2 particles, a set of fluid equations, governing the dynamics of such particles interacting with external fields and other particles, is derived. The equations describe electrons, positrons, holes, and similar conglomerates. In the case of electrons, the magnetohydrodynamic limit of an electron-i

Francis Comets, Serguei Popov, Gunter Schütz, Marina Vachkovskaia

We study stochastic billiards on general tables: a particle moves according to its constant velocity inside some domain ${\mathcal D} \subset {\mathbb R}^d$ until it hits the boundary and bounces randomly inside according to some reflection law. We assume that the boundary of the domain is locally Lipschitz and almost everywhere continuously differentiable.

Andrea Pulita

We develop the theory of $p$-adic confluence of $q$-difference equations. The main result is the surprising fact that, in the $p$-adic framework, a function is solution of a differential equation if and only if it is solution of a $q$-difference equation. This fact implies an equivalence, called ``Confluence&#39;&#39;, between the category of differential eq

Andrea Pulita

We introduce a new class of exponentials of Artin-Hasse type, called $\boldsymbolπ$-exponentials. These exponentials depends on the choice of a generator $\boldsymbolπ$ of the Tate module of a Lubin-Tate group $\mathfrak{G}$ over $\mathbb{Z}_p$. They arise naturally as solutions of solvable differential modules over the Robba ring. If $\mathfrak{G}$ is isomo

B. Feigin, E. Frenkel, V. Toledano-Laredo

We introduce a class of quantum integrable systems generalizing the Gaudin model. The corresponding algebras of quantum Hamiltonians are obtained as quotients of the center of the enveloping algebra of an affine Kac-Moody algebra at the critical level, extending the construction of higher Gaudin Hamiltonians from hep-th/9402022 to the case of non-highest wei

Marek Szydlowski, Orest Hrycyna

Dynamics of brane-world models of dark energy is reviewed. We demonstrate that simple dark energy brane models can be represented as 2-dimensional dynamical systems of a Newtonian type. Hence a fictitious particle moving in a potential well characterizes the model. We investigate the dynamics of the brane models using methods of dynamical systems. The simple

V. de Alfaro, A. T. Filippov

We introduce generalized dimensional reductions of an integrable 1+1-dimensional dilaton gravity coupled to matter down to one-dimensional static states (black holes in particular), cosmological models and waves. An unusual feature of these reductions is the fact that the wave solutions depend on two variables - space and time. They are obtained here both by

Yong-Geun Oh

In this paper, we prove that if a continuous Hamiltonian flow fixes the points in an open subset $U$ of a symplectic manifold $(M,ω)$, then its associated Hamiltonian is constant at each moment on $U$. As a corollary, we prove that the Hamiltonian of compactly supported continuous Hamiltonian flows is unique both on a compact $M$ with smooth boundary $\del M

Pavel Chebotarev

For a graph G, let f_{ij} be the number of spanning rooted forests in which vertex j belongs to a tree rooted at i. In this paper, we show that for a path, the f_{ij}&#39;s can be expressed as the products of Fibonacci numbers; for a cycle, they are products of Fibonacci and Lucas numbers. The {\em doubly stochastic graph matrix} is the matrix F=(f_{ij})/f,

Diego Cirilo-Lombardo

The mathematical structure of the Born-Infeld field equations was analyzed from the point of view of the symmetries. To this end, the field equations were written in the most compact form by means of quaternionic operators constructed according to all the symmetries of the theory, including the extension to a non-commutative structure. The quaternionic struc

Wojciech Smigaj

We propose a quantitative model explaining the mechanism of light collimation by leaky surface modes that propagate on a corrugated surface around the output of a photonic crystal waveguide. The dispersion relation of these modes is determined for a number of surface terminations. Analytical results obtained on the basis of the model are compared to those of

B. Habib, E. Tutuc, M. Shayegan

We measured Aharonov-Bohm resistance oscillations in a shallow two-dimensional GaAs hole ring structure, defined by local anodic surface oxidation. The amplitude of the oscillations is about 10% of the ring resistance, the strongest seen in a hole system. In addition we observe resistance oscillations as a function of front gate bias at zero magnetic field.

Ryan J. Foley, Nathan Smith, Mohan Ganeshalingam, Weidong Li

We present optical photometry and spectra of the peculiar Type Ib supernova (SN) 2006jc. Strong and relatively narrow He I emission lines indicate the progenitor star exploded inside a dense circumstellar medium (CSM) rich in He. An exceptionally blue apparent continuum persists from our first spectrum obtained 15 days after discovery through our last spectr

E. G. Mishchenko

Minimal conductivity of a single undoped graphene layer is known to be of the order of the conductance quantum, independent of the electron velocity. We show that this universality does not survive electron-electron interaction which results in the non-trivial frequency dependence. We begin with analyzing the perturbation theory in the interaction parameter

Greg W. Anderson, Ofer Zeitouni

We consider the spectral properties of a class of regularized estimators of (large) empirical covariance matrices corresponding to stationary (but not necessarily Gaussian) sequences, obtained by banding. We prove a law of large numbers (similar to that proved in the Gaussian case by Bickel and Levina), which implies that the spectrum of a banded empirical c

R. R. Metsaev

Using on-shell gauge invariant formulation of relativistic dynamics we study interaction vertices for a massive spin 5/2 Dirac field propagating in (A)dS space of dimension greater than or equal to four. Gravitational interaction vertex for the massive spin 5/2 field and all cubic vertices for the massive spin 5/2 field and massless spin 2 field with two and

A. R. Usha Devi, R. Prabhu, A. K. Rajagopal

A cogent theory of collective multipole-like quantum correlations in symmetric multiqubit states is presented by employing SO(3) irreducible spherical tensor representation. An arbitrary bipartite division of this system leads to a family of inequalities to detect entanglement involving averages of these tensors expressed in terms of the total system angular

M. La Camera

We consider brane cosmology when the 4D Ricci scalar term is added to the 5D Einstein-Hilbert action and discuss the role that the addition of this term has on the brane-bulk system. The induced brane dynamics is shown to be the usual Einstein dynamics coupled to a modified energy-momentum tensor which is well defined once the 5D Einstein equations are solve

D. E. Feldman, Yuval Gefen, Alexei Kitaev, K. T. Law

We show how shot noise in an electronic Mach-Zehnder interferometer in the fractional quantum Hall regime probes the charge and statistics of quantum Hall quasiparticles. The dependence of the noise on the magnetic flux through the interferometer allows for a simple way to distinguish Abelian from non-Abelian quasiparticle statistics. In the Abelian case, th

Yun-Su Kim

We introduce two kinds of quasi-inner functions. Since every rationally invariant subspace for a shift operator $S_K$ on a vector-valued Hardy space $H^{2}(Ω,K)$ is generated by a quasi-inner function, we also provide relationships of quasi-inner functions by comparing rationally invariant subspaces generated by them. Furthermore, we discuss fundamental prop

Emilio Santos

A family of local models containing two angles as hidden variables is defined for experiments measuring polarization correlation of optical photons. Searching for the best model of the family, that is giving predictions most close to quantum mechanics, allows deriving Bell-type inequalities which may be tested with relatively low detection efficiency.

Thomas Buchert

The effective evolution of an inhomogeneous universe model in Einstein&#39;s theory of gravitation may be described in terms of spatially averaged scalar variables. This evolution can be modeled by solutions of a set of Friedmann equations for an effective scale factor, with matter and backreaction source terms, where the latter can be represented by a minim

Alikram N. Aliev

We briefly discuss the theory of epicyclic motion near rotating black holes and its relation to the origin of high frequency Quasi-Periodic Oscillations (QPOs) seen in many cases of accreting black hole binaries. We also point out some new frequency ratios predicted by the theory.

S. N. Artemenko, Thomas Nattermann

We study formation of the charge-density wave long-range order in a system of repulsive 1D electrons coupled to 3D phonons. We show that the CDW can be stabilized by interaction with phonons in quasi-1D crystals and semiconducting nanowires. In the case of metallic atomic chains, interaction with phonons of 3D substrate is not enough, and violation of the tr

I. V. Barashenkov, S. R. Woodford, E. V. Zemlyanaya

We study interactions between the dark solitons of the parametrically driven nonlinear Schrödinger equation, Eq.(\ref{NLS}). When the driving strength, $h$, is below $\sqrt{γ^2 +1/9}$, two well-separated Néel walls may repel or attract. They repel if their initial separation $2z(0)$ is larger than the distance $2z_u$ between the constituents in the unstable

M. Pincetti, B. Pasquini, S. Boffi

Within the framework of light-cone quantization we derive the overlap representation of generalized parton distributions for transversely polarized quarks using the Fock-state decomposition in the transverse-spin basis. We apply this formalism to the case of light-cone wave functions in a constituent quark model giving numerical results for the four chiral-o

S. Negishi, H. Matsufuru, T. Onogi

We compute the B^*Bπcoupling \hat{g}_{\infty} for static heavy-light meson using all-to-all propagators. It is shown that low-mode averaging with 100 low-lying eigenmodes indeed improves the signal for the 2-point and 3-point functions for heavy-light meson significantly. Our study suggests that the all-to-all propagator will be a very efficient method for h

Kazuhide Ichikawa, Tomo Takahashi

We investigate observational constraints on the curvature of the universe not restricting ourselves to a cosmological constant as dark energy, in particular allowing a dark energy equation of state to evolve with time in several ways. We use type Ia supernovae (SNeIa) data from the latest gold data set which includes 182 SNeIa, along with the CMB shift param

Alexander Polishchuk

We show that a nondegenerate unitary solution $r(u,v)$ of the associative Yang-Baxter equation (AYBE) for $\Mat(N,\C)$ (see math.AG/0008156) with the Laurent series at $u=0$ of the form $r(u,v)=\frac{1\ot 1}{u}+r_0(v)+...$ satisfies the quantum Yang-Baxter equation, provided the projection of $r_0(v)$ to traceless matrices has a period. We classify all such

Bradley A. Foreman

A small change of basis in k.p theory yields a Kane-like Hamiltonian for the conduction and valence bands of narrow-gap semiconductors that has no spurious solutions, yet provides an accurate fit to all effective masses. The theory is shown to work in superlattices by direct comparison with first-principles density-functional calculations of the valence subb

Lin Xia, Xu Xu, Fan Yang, Wei Xiong

Manipulation of the quantum state by the Majorana transition in spinor BEC system has been realized by altering the rotation frequency of the magnetic field&#39;s direction. This kind of manipulation method has no limitation on the transition speed in principle and the system is well closed, which provides a new and superior tool to manipulate quantum states

F. M. C. Witte

In this paper I reconsider the use of the left ideals of the even-grade subalgebra of spacetime algebra to describe fermionic excitations. When interpreted as rotors the general elements of an even-grade left-ideal describe massless particles in chiral flavour doublets. To study the application of these ideas to the standard Dirac formalism I construct a $2

Lisa Carbone, Mikhail Ershov, Gordon Ritter

Let $G$ be a Kac-Moody group over a finite field corresponding to a generalized Cartan matrix $A$, as constructed by Tits. It is known that $G$ admits the structure of a BN-pair, and acts on its corresponding building. We study the complete Kac-Moody group $\hat{G}$ which is defined to be the closure of $G$ in the automorphism group of its building. Our main

Alexander Jurisch

In this article, we develop quantum mechanics upon the framework of the quantum mechanical Hamilton-Jacobi theory. We will show, that the Schroedinger point of view and the Hamilton-Jacobi point of view are fully equivalent in their description of physical systems, but differ in their descriptive manner. As a main result, a wave function in Hamilton-Jacobi t

N. David Mermin

The role of measurement in quantum computation is examined in the light of John Bell&#39;s critique of the how the term ``measurement&#39;&#39; is used in quantum mechanics. I argue that within the field of quantum computer science the concept of measurement is precisely defined, unproblematic, amd forms the foundation of the entire subject.

Gian Paolo Beretta

We discuss and motivate the form of the generator of a nonlinear quantum dynamical group &#39;designed&#39; so as to accomplish a unification of quantum mechanics (QM) and thermodynamics. We call this nonrelativistic theory Quantum Thermodynamics (QT). Its conceptual foundations differ from those of (von Neumann) quantum statistical mechanics (QSM) and (Jayn

M. Holman

Two recent arguments for linear dynamics in quantum theory are critically re-examined. Neither argument is found to be satisfactory as it stands, although an improved version of one of the arguments can in fact be given. This improved version turns out to be still not completely unproblematic, but it is argued that it contains only a single actual loophole,

Paul Schoessow, Alexei Kanareykin, Levi Schachter, Yuriy Bogachev

The PASER is potentially a very attractive method for particle acceleration, in which energy from an active medium is transferred to a charged particle beam. The effect is similar to the action of a maser or laser with the stimulated emission of radiation being produced by the virtual photons in the electromagnetic field of the beam. We have been investigati

A. Kanareykin, E. Nenasheva, V. Yakovlev, A. Dedyk

Fast switching (< 10 nsec) measurement results on the recently developed BST(M) (barium strontium titanium oxide composition with magnesium-based additions) ferroelectric materials are presented. These materials can be used as the basis for new advanced technology components suitable for high-gradient accelerators. A ferroelectric ceramic has an electric fie

Afsar Abbas

Normally one plots separation energies $S_{1n}$ and $S_{2n}$ as a function of neutron number $N$ for a particular proton number $Z$ or plot $S_{1p}$ and $S_{2p}$ as a function of $Z$ for a particular $N$. Here we plot the separation energies a little differently: $S_{1n}$ and $S_{2n}$ as a function of $Z$ for a particular $N$. The same with $S_{1p}$ and $S_{

Andrey Tyukhtin, Alexei Kanareykin, Paul Schoessow

The wakefields of a relativistic electron beam passing through a waveguide loaded with an active medium with weak resonant dispersion have been considered. For the calculations in this paper the parameters of the medium are those of a solution of fullerene (C60) in a nematic liquid crystal that exhibits activity in the X-band. It was shown that several of th

M. Wilkinson, B. Mehlig, S. Ostlund, K. P. Duncan

We consider particles suspended in a randomly stirred or turbulent fluid. When effects of the inertia of the particles are significant, an initially uniform scatter of particles can cluster together. We analyse this &#39;unmixing&#39; effect by calculating the Lyapunov exponents for dense particles suspended in such a random three-dimensional flow, concentra

Vsevolod E. Adler, Alexey B. Shabat

The classification problem is solved for some type of nonlinear lattices. These lattices are closely related to the lattices of Ruijsenaars-Toda type and define the Backlund auto-transformations for the class of two-component hyperbolic systems.

T. Miyaguchi

Chaotic orbits of mushroom billiards display intermittent behaviors. We investigate statistical properties of this system by constructing an infinite partition on the chaotic part of a Poincaré surface which illustrates details of chaotic dynamics. Each piece of the infinite partition has an unique escape time from the half disk region, and from this result

Andreas Raab

We use nonstandard analysis to formulate quantum mechanics in hyperfinite-dimensional spaces. Self-adjoint operators on hyperfinite-dimensional spaces have complete eigensets, and bound states and continuum states of a Hamiltonian can thus be treated on an equal footing. We show that the formalism extends the standard formulation of quantum mechanics. To thi

Joerg Zintl

There is a well-known stratification of the moduli space $M_g$ of Deligne-Mumford stable curves of genus $g$ by the loci of stable curves with a fixed number $i$ of nodes, where $i \le 3g-3$. The associated moduli stack ${\cal M}_g$ admits an analogous stratification. Our main objects of study are those one-dimensional substacks of the moduli stack, which ar

Alexander Samokhin

In this paper we prove first a general theorem on semiorthogonal decompositions in derived categories of coherent sheaves for flat families over a smooth base. Based on the results of math.AG/0510670, we then show that the derived categories of coherent sheaves on flag varieties of classical type are generated by complete exceptional collections. Finally, we

Janos Englander

In a previous paper of Winter and the author the Law of Large Numbers for the local mass of certain superdiffusions was proved under a spectral theoretical assumption, which is equivalent to the ergodicity (positive recurrence) of the motion component of an $H$-transformed (or weighted) superprocess. In fact the assumption is also equivalent to the property

Tahl Nowik

The self intersection of an immersion i : S^2 \to R^3 dissects S^2 into pieces which are planar surfaces (unless i is an embedding). In this work we determine what collections of planar surfaces may be obtained in this way. In particular, for every n we construct an immersion i : S^2 \to R^3 with 2n triple points, for which all pieces are discs.

Sergei V. Gusev

The paper considers a linear matrix inequality (LMI) that depends on a parameter varying in a compact topological space. It turns out that if a strict LMI continuously depends on a parameter and is feasible for any value of that parameter, then it has a solution which continuously depends on the parameter. The result holds true for LMIs that arise in S-proce

E. I. Ganzha, V. M. Loginov, S. P. Tsarev

For hyperbolic first-order systems of linear partial differential equations (master equations), appearing in description of kinetic processes in physics, biology and chemistry we propose a new procedure to obtain their complete closed-form non-stationary solutions. The methods used include the classical Laplace cascade method as well as its recent generaliza

Donald B. Rubin

Rejoinder on Causal Inference Through Potential Outcomes and Principal Stratification: Application to Studies with ``Censoring&#39;&#39; Due to Death by D. B. Rubin [math.ST/0612783]

Stephen E. Fienberg

Comment on Complex Causal Questions Require Careful Model Formulation: Discussion of Rubin on Experiments with ``Censoring&#39;&#39; Due to Death [math.ST/0612783]

Alexei Yu. Karlovich

We prove asymptotic formulas for Toeplitz determinants generated by functions with sequences of Fourier coefficients belonging to weighted Orlicz sequence classes. We concentrate our attention on the case of nonvanishing generating functions with nonzero Cauchy index.

Paul R. Rosenbaum

Comment on The Place of Death in the Quality of Life [math.ST/0612783]

Edward L. Korn

Comment on Causal Inference in the Medical Area [math.ST/0612783]

stefano m. iacus, nakahiro yoshida

The telegraph process $\{X(t), t>0\}$, is supposed to be observed at $n+1$ equidistant time points $t_i=iΔ_n,i=0,1,..., n$. The unknown value of $λ$, the underlying rate of the Poisson process, is a parameter to be estimated. The asymptotic framework considered is the following: $Δ_n \to 0$, $nΔ_n = T \to \infty$ as $n \to \infty$. We show that previously pr

Donald B. Rubin

Causal inference is best understood using potential outcomes. This use is particularly important in more complex settings, that is, observational studies or randomized experiments with complications such as noncompliance. The topic of this lecture, the issue of estimating the causal effect of a treatment on a primary outcome that is ``censored'' by death, is

Ilia Itenberg, Viatcheslav Kharlamov, Eugenii Shustin

We consider the product of two projective lines equipped with the complex conjugation transforming $(x,y)$ into $(\bar{y},\bar{x})$ and blown up in at most two real, or two complex conjugate, points. For these four surfaces we prove the logarithmic equivalence of Welschinger and Gromov-Witten invariants.

N. Aizawa, M. Harada, M. Kawaguchi, E. Otsuki

All polynomial invariants of links for two dimensional solutions of Yang-Baxter equation is constructed by employing Turaev&#39;s method. As a consequence, it is proved that the best invariant so constructed is the Jones polynomial and there exist three solutions connecting to the Alexander polynomial. Invariants for higher dimensional solutions, obtained by

Ingolf Schäfer

Starting with an operator in the universal enveloping algebra of a semi-simple, complex Lie group the nearest neighbor statistics of the spectra of this operator along a sequence of representations are discussed. After a short introduction in chapter 1 this problem is motivated by a general construction of the classical limit for quantum mechanical systems,

Ingo Steinwart, Don Hush, Clint Scovel

We establish a new concentration result for regularized risk minimizers which is similar to an oracle inequality. Applying this inequality to regularized least squares minimizers like least squares support vector machines, we show that these algorithms learn with (almost) the optimal rate in some specific situations. In addition, for regression our results s

Nataša Kejžar, Zoran Nikoloski, Vladimir Batagelj

Models of complex networks are generally defined as graph stochastic processes in which edges and vertices are added or deleted over time to simulate the evolution of networks. Here, we define a unifying framework - probabilistic inductive classes of graphs - for formalizing and studying evolution of complex networks. Our definition of probabilistic inductiv

Evarist Giné, Vladimir Koltchinskii

Let ${M}$ be a compact Riemannian submanifold of ${{\bf R}^m}$ of dimension $\scriptstyle{d}$ and let ${X_1,...,X_n}$ be a sample of i.i.d. points in ${M}$ with uniform distribution. We study the random operators $$ Δ_{h_n,n}f(p):=\frac{1}{nh_n^{d+2}}\sum_{i=1}^n K(\frac{p-X_i}{h_n})(f(X_i)-f(p)), p\in M $$ where ${K(u):={\frac{1}{(4π)^{d/2}}}e^{-\|u\|^2/4}}

P. P. B. Eggermont, V. N. LaRiccia

Almost sure bounds are established on the uniform error of smoothing spline estimators in nonparametric regression with random designs. Some results of Einmahl and Mason (2005) are used to derive uniform error bounds for the approximation of the spline smoother by an ``equivalent&#39;&#39; reproducing kernel regression estimator, as well as for proving unifo

Rudra p Sarkar, Jyoti Sengupta

We prove Beurling&#39;s theorem for the full group $SL(2,\R)$. This is the {\em master theorem} in the quantitative uncertainty principle as all the other theorems of this genre follow from it.

Zhenxin Liu

In this paper, stochastic inertial manifold for damped wave equations subjected to additive white noise is constructed by the Lyapunov-Perron method. It is proved that when the intensity of noise tends to zero the stochastic inertial manifold converges to its deterministic counterpart almost surely.

Toshiyuki Akita

An unusual formula for the Euler characteristics of even dimensional triangulated manifolds is deduced from the generalized Dehn-Sommerville equations.

Evarist Giné, Vladimir Koltchinskii, Wenbo Li, Joel Zinn

About forty years ago it was realized by several researchers that the essential features of certain objects of Probability theory, notably Gaussian processes and limit theorems, may be better understood if they are considered in settings that do not impose structures extraneous to the problems at hand. For instance, in the case of sample continuity and bound

Wu-yen Chuang, Peng Gao

We study the effect of flux-induced isometry gauging of the scalar manifold in N=2 heterotic string compactification with gauge fluxes. We show that a vanishing theorem by Witten provides the protection mechanism. The other ungauged isometries in hyper moduli space could also be protected, depending on the gauge bundle structure. We also discuss the related

W. Galleas, M. J. Martins

We have diagonalized the transfer matrix of the $U_{q}[osp(2|2m)]$ vertex model by means of the algebraic Bethe ansatz method for a variety of grading possibilities. This allowed us to investigate the thermodynamic limit as well as the finite size properties of the corresponding spin chain in the massless regime. The leading behaviour of the finite size corr

Jerzy Kowalski-Glikman

The current status of Doubly Special Relativity research program is shortly presented. I dedicate this paper to my teacher and friend Professor Jerzy Lukierski on occasion of his seventieth birthday.

Fumikazu Koyama, Futoshi Yagi

We extend the detailed analysis of the quantum moduli space of the cascading SU(p+M) x SU(p) gauge theory in the recent paper of Dymarsky, Klebanov, and Seiberg for the Sp(p+M) x Sp(p) cascading gauge theory, which lives on the world volume of p D3-branes and M fractional D3-branes at the tip of the orientifolded conifold. As in their paper, we also find in

Igor A. Bandos, Jose A. de Azcarraga

We briefly review here the notion of BPS preons, the hypothetical constituents of M-theory, emphasizing its generalization to arbitrary dimensions D and its relation to higher spin theories in D=4,6 and 10.

Francesco Toppan

In this talk we review the classification of the irreducible representations of the algebra of the N-extended one-dimensional supersymmetric quantum mechanics presented in hep-th/0511274. We answer some issues raised in hep-th/0611060, proving the agreement of the results here contained with those in hep-th/0511274. We further show that the fusion algebra of

Yasuyuki Hatsuda, Keisuke Okamura

Generalizing the idea of hep-th/0509015 by Berenstein, Correa, and Vazquez, we study many-magnon states in an SU(2) sector of a reduced matrix quantum mechanics obtained from N=4 SU(N) super Yang-Mills on R x S^3. Generic Q-magnon states are described as a chain of ``string-bits&#39;&#39; joining Q+1 eigenvalues of background matrices which form a 1/2 BPS ci

P. Aurenche, B. G. Zakharov

We give a simple physical derivation of the photon emission rate from the weakly coupled quark-gluon plasma connected with the collinear processes $q\to γq$ and $q\bar{q}\to γ$. The analysis is based on the light-cone path integral approach to the induced radiation. Our results agree with that by Arnold, Moore and Yaffe obtained using the real-time thermal p

V. I. Zakharov

We discuss relation between lattice phenomenology of confining fields in the vacuum state of Yang-Mills theories (mostly SU(2) case) and continuum theories. In the continuum, understanding of the confinement is most straightforward in the dual formulation which involves higher dimensions. We try to bridge these two approaches to the confinement, let it be on