October 2001 arXiv papers — page 3

Jorge Kurchan

Elementary algebraic constraints on the form of an autocorrelation function C(tw+t,tw)=<A(tw+t)A(tw)> rule out some two-time scalings found in the literature as possible long-time asymptotic forms. The same argument leads to the realization that two usual definitions of {\em many-time scale} relaxation for aging systems are not equivalent.

J. Dziarmaga, A. Smerzi, W. H. Zurek, A. R. Bishop

We study the dynamics of the Mott insulator-superfluid quantum phase transition in a periodic 1D array of Josephson junctions. We show that crossing the critical point diabatically i.e. at a finite rate with a quench time $τ_Q$ induces finite quantum fluctuations of the current around the loop proportional to $τ_Q^{-1/6}$. This scaling could be experimentall

Hugh R. A. Jones, Yakiv Pavlenko, Serena Viti, Jonathan Tennyson

M star spectra, at wavelengths beyond 1.35 $μ$m, are dominated by water vapour yet terrestrial water vapour makes it notoriously difficult to make accurate measurement from ground-based observations. We have used the short wavelength spectrometer on the Infrared Space Observatory at four wavelength settings to cover the 2.5--3.0 $μ$m region for a range of M

Charis Anastopoulos

We study how the spin-statistics theorem relates to the geometric structures on phase space that are introduced in quantisation procedures (namely a U(1) bundle and connection). The relation can be proved in both the relativistic and the non-relativistic domain (in fact for any symmetry group including internal symmetries) without quantum field theory, by th

XuBo Zou, K. Pahlke, W. Mathis

We present a feasible scheme to produce a polarization-entangled photon states $\frac{1}{\sqrt{2}}(|H>|V>+|V>|H>)$ in a controllable way. This scheme requires single-photon sources, linear optical elements and photon detectors. It generates the entanglement of spatially separated photons. The interaction takes place in the photon detectors. We also show that

Laura Andrianopoli, Riccardo D&#39;Auria, Sergio Ferrara

We consider the possible consistent truncation of N-extended supergravities to lower N&#39; theories. The truncation, unlike the case of N-extended rigid theories, is non trivial and only in some cases it is sufficient just to delete the extra N-N&#39; gravitino multiplets. We explore different cases (starting with N=8 down to N&#39;\geq 2) where the reducti

C. Munoz

Assuming that the Standard Model of particle physics arises from the $E_8\times E_8$ Heterotic String Theory, we try to solve the discrepancy between the unification scale predicted by this theory ($\approx g_{GUT}\times 5.27\cdot 10^{17}$ GeV) and the value deduced from LEP experiments ($\approx 2\cdot 10^{16}$ GeV). A crucial ingredient in our solution is

A. Cavaliere, V. Vittorini

We discuss the link between the observations of distant quasars and those of massive dark objects in the cores of many local galaxies. We show how the formation of early black holes gives rise to the luminosity function of high z quasars, while it imprints into their dark local relics a related shape of the mass-dispersion correlation. We propose that in its

Yoshihide Tanaka, Akira Oguri, Hiroumi Ishii

We study the effects of electron correlation on transport through an interacting region connected to multi-mode leads based on the perturbation expansion with respect to the inter-electron interaction. At zero temperature the conductance defined in the Kubo formalism can be written in terms of a single-particle Green&#39;s function at the Fermi energy, and i

V. D. Ivashchuk, V. N. Melnikov

This topical review deals with a multidimensional gravitational model containing dilatonic scalar fields and antisymmetric forms. The manifold is chosen in the form M = M_0 x M_1 x ...x M_n, where M_i are Einstein spaces (i >0). The sigma-model approach and exact solutions in the model are reviewed and the solutions with p-branes (e.g. Majumdar-Papapetrou-ty

Yosuke Uehara

We consider the production of black holes caused by the collision between high-energy cosmic neutrinos and nuclei contained in detectors. If the fundamental scale M_{*} is O(TEV), as some higher-dimensional theories suggest, ICECUBE detector may observe about 10^{4} - 10^{2} black holes per year.

Sergiu I. Vacaru, D. Singleton

In this paper we construct and analyze new classes of wormhole and flux tube-like solutions for the 5D vacuum Einstein equations. These 5D solutions possess generic local anisotropy which gives rise to a gravitational running or scaling of the Kaluza-Klein ``electric&#39;&#39; and ``magnetic&#39;&#39; charges of these solutions. It is also shown that it is p

J. M. Zanotti, S. Bilson-Thompson, F. D. R. Bonnet, P. D. Coddington

The hadron mass spectrum is calculated in lattice QCD using a novel fat-link clover fermion action in which only the irrelevant operators in the fermion action are constructed using smeared links. The simulations are performed on a 16^3 x 32 lattice with a lattice spacing of a=0.125 fm. We compare actions with n=4 and 12 smearing sweeps with a smearing fract

Max Pettini, Samantha A. Rix, Charles C. Steidel, Kurt L. Adelberger

We present the results of a detailed study of the interstellar medium of MS 1512-cB58, an L* Lyman break galaxy at z = 2.7276, based on new spectral observations obtained with the Echelle Spectrograph and Imager on the Keck II telescope at 58 km/s resolution. We focus in particular on the chemical abundances and kinematics of the interstellar gas and our mai

Yoji Michishita

We investigate D-branes with maximal symmetry on general group manifolds in terms of boundary states and effective actions. We show that in large $k$ limit boundary states with an suitable Wilson line form boundary states of the other types of D-branes, extending the known fact in SU(2) case. We also show that fluctuation mass spectrum around D-brane solutio

Ayman F. Abouraddy, Alexander V. Sergienko, Bahaa E. A. Saleh, Malvin C. Teich

A formalism for two-photon Stokes parameters is introduced to describe the polarization entanglement of photon pairs. This leads to the definition of a degree of two-photon polarization, which describes the extent to which the two photons act as a pair and not as two independent photons. This pair-wise polarization is complementary to the degree of polarizat

Jens Eggers

We give a brief overview of the physical significance of singularities in fluid mechanics.

S. Ando, F. Myhrer, K. Kubodera

Theoretical difficulties in reconciling the measured rates for ordinary and radiative muon capture are discussed, based on heavy-baryon chiral perturbation theory. We also examine ambiguity in our analysis due to the formation of p$μ$p molecules in the liquid hydrogen target.

S. K. Patra, X. Vinas, M. Centelles, M. Del Estal

We derive analytical expressions for the excitation energy of the isoscalar giant monopole and quadrupole resonances in finite nuclei, by using the scaling method and the extended Thomas-Fermi approach to relativistic mean field theory. We study the ability of several non-linear sigma-omega parameter sets of common use in reproducing the experimental data. F

S. K. Patra, M. Centelles, X. Vinas, M. Del Estal

By using the scaling method we derive the virial theorem for the relativistic mean field model of nuclei treated in the Thomas-Fermi approach. The Thomas-Fermi solutions statisfy the stability condition against scaling. We apply the formalism to study the excitation energy of the breathing mode in finite nuclei with several relativistic parameter sets of com

R. G. Nazmitdinov, D. Almehed, F. Donau

The contribution of quantum shape fluctuations to inertial properties of rotating nuclei has been analysed within the self-consistent one-dimensional cranking oscillator model. It is shown that in even-even nuclei the dynamical moment of inertia calculated in the mean field approximation is equivalent to the Thouless-Valatin moment of inertia calculated in t

M. V. Andres, F. Catara, E. G. Lanza, Ph. Chomaz

We calculate the inelastic scattering cross sections to populate one- and two-phonon states in heavy ion collisions with both Coulomb and nuclear excitations. Starting from a microscopic approach based on RPA, we go beyond it in order to treat anharmonicities and non-linear terms in the exciting field. These anharmonicities and non-linearities are shown to h

Nicolas Borghini, Phuong Mai Dinh, Jean-Yves Ollitrault

We have recently proposed a new method of flow analysis, based on a cumulant expansion of multiparticle azimuthal correlations. Here, we describe the practical implementation of the method. The major improvement over traditional methods is that the cumulant expansion eliminates order by order correlations not due to flow, which are often large but usually ne

Tor Fla

We parameterize the phase space density by time dependent diffeomorphic, Poisson preserving transformations on phase space acting on a reference density solution. We can look at these as transformations which fix time on the extended space of phase space and time. In this formulation the Vlasov equation is replaced by a constraint equation for the above maps

Hans F. de Groote

In this paper we start with the development of a theory of presheaves on a lattice, in particular on the quantum lattice $\LL(\kH)$ of closed subspaces of a complex Hilbert space $\kH$, and their associated etale spaces. Even in this early state the theory has interesting applications to the theory of operator algebras and the foundations of quantum mechanic

Gian Fausto Dell&#39;Antonio, Gianluca Panati

The flux-across-surfaces conjecture represents a corner stone in quantum scattering theory because it is the key-assumption needed to prove the usual relation between differential cross section and scattering amplitude. We improve a recent result [TDMB] by proving the conjecture also in presence of zero-energy resonances or eigenvalues, both in point and pot

Alexei Borodin

We show how the Riemann-Hilbert problem can be used to compute correlation kernels for determinantal point processes arising in different models of asymptotic combinatorics and representation theory. The Whittaker kernel and the discrete Bessel kernel are computed as examples.

Brian Ingalls, Eduardo D. Sontag

A general ISS-type small-gain result is presented. It specializes to a small-gain theorem for ISS operators, and it also recovers the classical statement for ISS systems in state-space form. In addition, we highlight applications to incrementally stable systems, detectable systems, and to interconnections of stable systems.

Wojciech Chacholski, Jerome Scherer

In this paper we develop homotopy theoretical methods for studying diagrams. In particular we explain how to construct homotopy colimits and limits in an arbitrary model category. The key concept we introduce is that of a model approximation. Our key result says that if a category admits a model approximation then so does any diagram category with values in

Jose M. Isidro

Given a complex Hilbert space H, we study the differential geometry of the manifold A of normal algebraic elements in Z=L(H), the algebra of bounded linear operators on H. We represent A as a disjoint union of subsets M of Z and, using the algebraic structure of Z, a torsionfree affine connection $\nabla$ (that is invariant under the group G= Aut (Z) of auto

Rocio Gonzalez-Diaz, Pedro Real

In this note, working in the context of simplicial sets, we give a detailed study of the complexity for computing chain level Steenrod squares, in terms of the number of face operators required. This analysis is based on the combinatorial formulation given in [R. Gonzalez-Diaz, P. Real. A Combinatorial Method for Computing Steenrod Squares. J. of Pure and Ap

Per K. Jakobsen, Valentin Lychagin

In this paper we develope a categorical theory of relations and use this formulation to define the notion of quantization for relations. Categories of relations are defined in the context of symmetric monoidal categories. They are shown to be symmetric monoidal categories in their own right and are found to be isomorphic to certain categories of $A-A$ bicomo

Bogdan Alexandrov

We call a quaternionic Kaehler manifold with non-zero scalar curvature, whose quaternionic structure is trivialized by a hypercomplex structure, a hyper-Hermitian quaternionic Kaehler manifold. We prove that every locally symmetric hyper-Hermitian quaternionic Kaehler manifold is locally isometric to the quaternionic projective space or to the quaternionic h

Michael Hitrik, Iosif Polterovich

We compute the coefficients in asymptotics of regularized traces and associated trace (spectral) distributions for Schrodinger operators, with short and long range potentials. A kernel expansion for the Schrodinger semigroup is derived, and a connection with non-commutative Taylor formulas is established.

Sergiu I. Vacaru

The &#39;anholonomic frame&#39; method (see gr-qc/0005025, gr-qc/0001060 and hep-th/0110250) is applied for constructing new classes of exact solutions of vacuum Einstein equations with off-diagonal metrics in 4D and 5D gravity. We examine several black tori solutions generated by anholonomic transforms with non-trivial topology of the Schwarzshild metric, w

Eric D&#39;Hoker, D. H. Phong

A detailed derivation from first principles is given for the unambiguous and slice-independent formula for the two-loop superstring chiral measure which was announced in the first paper of this series. Supergeometries are projected onto their super period matrices, and the integration over odd supermoduli is performed by integrating over the fibers of this p

Pietro Fré

In this talk I review the recent construction of a new family of classical BPS solutions of type IIB supergravity describing 3-branes transverse to a 6-dimensional space with topology $\mathbb{R}^{2}\times$ALE. They are characterized by a non-trivial flux of the supergravity 2-forms through the homology 2-cycles of a generic smooth ALE manifold. These soluti

A. Jellal, T. D. Palev, J. Van der Jeugt

A-statistics is defined in the context of the Lie algebra sl(n+1). Some thermal properties of A-statistics are investigated under the assumption that the particles interact only via statistical interaction imposed by the Pauli principle of A-statistics. Apart from the general case, three particular examples are studied in more detail: (a) the particles have

Guy Auberson, Michel Capdequi Peyranere

Multiple scale techniques are well-known in classical mechanics to give perturbation series free from resonant terms. When applied to the quantum anharmonic oscillator, these techniques lead to interesting features concerning the solution of the Heisenberg equations of motion and the Hamiltonian spectrum.

V. D. Ivashchuk, V. N. Melnikov

A (1 + d)-dimensional thick &#34;brane world&#34; model with varying Lambda-term is considered. The model is generalized to the case of a chain of Ricci-flat internal spaces when the matter source is an anisotropic perfect fluid. The &#34;horizontal&#34; part of potential is obtained in the Newtonian approximation. In the multitemporal case (with a Lambda-te

Csaba Csaki

We investigate spacetimes in which the speed of light along flat 4D sections varies over the extra dimensions due to different warp factors for the space and the time coordinates (``asymmetrically warped&#39;&#39; spacetimes). The main property of such spaces is that while the induced metric is flat, implying Lorentz invariant particle physics on a brane, bu

Ning Wu

The quantum gravity is formulated based on principle of local gauge invariance. The model discussed in this paper has local gravitational gauge symmetry and gravitational field appears as gauge field. The problems on quantization and renormalization of the theory are also discussed in this paper. In leading order approximation, the gravitational gauge field

Robert Wimmer

We investigate the issue of regularization/renormalization in the presence of a nontrivial background in the case of 1+1-(supersymmetric) solitons. In particular we study and compare the commonly employed regularization methods (mode- energy/momentum- cutoff and derivative regularization). We show that the main point for a consistent regularization/renormali

C. H. Otto Chui, Christian Mercat, Paul A. Pearce

We derive the fusion hierarchy of functional equations for critical A-D-E lattice models related to, the sl(2) unitary minimal models, the parafermionic models and the supersymmetric models of conformal field theory, and deduce the related TBA functional equations. The derivation uses fusion projectors and applies in the presence of all known integrable boun

L. Bonora, M. Salizzoni

We discuss the problem of noncommutative SO(N) gauge field theories from the string one-loop point of view. To this end we propose an expression for the string propagator on the boundary of the Moebius strip in the presence of a constant B field. We discuss in detail the problems related to its derivation. Then we use it to compute the one-loop corrections t

Isabela P. Cavalcante, J. Sá Borges

Pion-pion scattering amplitude obtained from one-loop Chiral Perturbation Theory (ChPT) is crossing symmetric, however the corresponding partial wave amplitudes do not respect exact unitarity relation. There are different approaches to get unitarized partial wave amplitudes from ChPT. Here we consider the inverse amplitude method (IAM) that is often used to

M. S. Berger

We review the role of a muon collider in the study of Higgs bosons via production in the s-channel. Very precise measurements of a Standard Model-like Higgs boson mass and total width can be performed, and may lead to a discrimination between a Standard Model Higgs boson and the light Higgs boson of the minimal supersymmetric theory. The heavier Higgs bosons

B. A. Arbuzov

In electroweak theory without elementary Higgs scalars existence of a solution, which breaks initial symmetry is shown. A composite scalar doublet serves as a substitute for usual Higgs. The mass of the surviving Higgs scalar is predicted to be $M_H = 117 \pm 7 GeV$. The resulting theory contains realistic $W, Z, t$ masses and composite massive Higgs. Parame

C. Greub, M. Walker

We present the results of the O(alpha_s) two-loop virtual corrections to the differential decay width dGamma(B -> X_s l+ l-)/ds, where s is the invariant mass squared of the lepton pair. Those contributions from gluon bremsstrahlung which are needed to cancel infrared and collinear singularities are also included. Our calculation is restricted to the range 0

Rathin Adhikari, Raghavan Rangarajan

It has been argued in the past that in baryogenesis via out-of-equilibrium decays one must consider loop diagrams that contain more than one baryon number violating coupling. In this note we argue that the requirement with regard to baryon number violating couplings in loop diagrams is that the interaction between the intermediate on-shell particles and the

A. Cooper-Sarkar

NLO QCD fits using the DGLAP formalism have been made to the high precision ZEUS $e^+p$ reduced cross-section data and to fixed target structure function data, in order to detrmine parton distribution functions and the value of $α_s(M^2_Z)$, taking full account of correlated systematic errors. Preliminary results are reported.

S. F. King

In this talk, based on \cite{Kane:2001rb}, we emphasise that intermediate scale supersymmetric inflation models are particularly attractive since inflation, baryogenesis and the relic abundance of cold dark matter (CDM) are all related by a set of parameters which also affect particle physics collider phenomena, neutrino masses and the strong CP problem. We

Mrinal Dasgupta, Hans-Ulrich Martyn

Resummed results are discussed for DIS event shape variable distributions involving the thrust defined using the thrust axis of the current hemisphere, the C parameter and the jet mass. The resummation of these variables requires the development of some techniques different to those applied before for the resummation of DIS event shapes. Including power corr

Motoi Endo, Takeo Moroi

We study the muon magnetic dipole moment and the Higgs mass in the framework of the supersymmetric SU(5) models. In this analysis, all the relevant parameters in the Lagrangian are taken to be free; in particular, assumption of the universal scalar mass is not adopted. Negative search for the Higgs boson at the LEP II experiment sets an important constraint

S. J. Dong, T. Draper, I. Horvath, F. X. Lee

We report our calculation of the pion decay constant $f_π$, the axial renormalization constant $Z_A$, and the quenched chiral logarithms from the overlap fermions. The calculation is done on a quenched $20^4$ lattice at $a=0.148$ fm using tree level tadpole improved gauge action. The smallest pion mass we reach is about 280 MeV. The lattice size is about 4 t

P. Bialas, A. Morel, B. Petersson, K. Petrov

We discuss the screening masses and residue factorisation of the SU(3) (2+1)D theory in the dimensional reduction formalism. The phase structure of the reduced model is also investigated.

P. Hernandez

I review recent progress in the implementation of lattice fermions satisfying the Ginsparg-Wilson relation and some physical applications.

Valery M. Biryukov

An analytical theory for the efficiency of particle extraction from an accelerator by means of a bent crystal is proposed. The theory agrees with all the measurements performed in the broad energy range of 14 to 900 GeV, where the efficiency range also spans over two decades, from 0.3% to 30%. Possibilities for crystal extraction from sub-GeV accelerators an

J. H. Vossebeld

Recent results on jet and inclusive charged particle production in hadronic e+e- interactions are reviewed.

Richard Nisius

The status of and ongoing developments in the measurements and theoretical studies of the structure of the photon have been presented at the PHOTON 2001 conference in Ascona. The results presented in the structure function session are briefly summarised.

J. Drees

After a comment on the performance of LEP some highlights of the LEP1 and LEP2 physics programmes are reviewed. The talk concentrates on the precision measurements at the Z resonance, two fermion production above the Z, W+W- production, ZZ production, indirect limits on the Higgs mass, LEP contributions to the exploration of the CKM matrix, and on the LEP me

P. Janot

After years of efforts to push the LEP performance to, and indeed beyond, the limits of what had been believed possible, hints of signal of a Higgs boson at 115GeV/c2 appeared in June 2000, were confirmed in September, and confirmed again in November. Spending an additional six-month period with LEP would have given the unambiguous opportunity of a fundament

Valery Dorofeev, for VES Collaboration

We present preliminary results of study of the ethapi-, etha&#39;pi- and b1pi systems produced in the pi-Be-interaction at 28GeV/c. JPC=2++ and 1-+-waves resulted from the PWA have been fitted in each system separately to establish the nature of the 1-+ wave. A hypothesis of the 1-+ wave resonant nature in the ethapi- and etha&#39;pi- has no statistically si

Guo-ming Hen, Min Yang, Zhao-Hua Xiong, Hai-Jun Yang

The paper has heen withdrawn.

Marat Gataullin

Extra spatial dimensions are proposed by recent theories that postulate the fundamental gravitational scale to be of the same order as the electroweak scale. Different final states and search strategies are used by LEP collaborations to search for the signs of extra spatial dimensions. A brief review of the search strategies and results from all four LEP exp

P. A. Zizzi

In a previous paper (gr-qc/0103002), the inflationary universe was described as a quantum growing network (QGN). Here, we propose our view of the QGN as the &#34;ultimate Internet&#34;, as it saturates the quantum limits to computation. Also, we enlight some features of the QGN which are related to: i) the problem of causality at the Planck scale, ii) the qu

Bjorn Hjelm

When the European Telecommunications Standards Institute (ETSI) selected a radio access technology based on Wideband Code-Division Multiple Access (WCDMA), sponsored by European telecommunications equipment manufactures Ericsson and Nokia, for its third-generation wireless communications system, a bitter dispute developed between ETSI and Qualcommm Inc. Qual

Sylvie Boldo, Marc Daumas, Claire Moreau-Finot, Laurent Thery

Most existing implementations of multiple precision arithmetic demand that the user sets the precision {\em a priori}. Some libraries are said adaptable in the sense that they dynamically change the precision of each intermediate operation individually to deliver the target accuracy according to the actual inputs. We present in this text a new adaptable nume

Yung M. Huh, D. K. Finnemore

Thermodynamic critical field curves have been measured for $La_{2-x}Sr_{x}CuO_{4+δ}$ over the full range of carrier concentrations where superconductivity occurs in order to determine changes in the normal state density of states with carrier concentration. There is a substantial window in the $H-T$ plane where the measurements are possible because the sampl

G. Varelogiannis

Taking into account the first localization corrections in the electron-impurity self-energy we study the effect of non-magnetic impurities on unconventional superconductivity (SC) mediated by small-q electron-phonon scattering. We show that when van Hove singularities are close to the Fermi level making the electronic system anisotropic as in the high-$T_c$

R. Di Felice, A. Calzolari, E. Molinari, A. Garbesi

Several assemblies of guanine molecules are investigated by means of first-principle calculations. Such structures include stacked and hydrogen-bonded dimers, as well as vertical columns and planar ribbons, respectively, obtained by periodically replicating the dimers. Our results are in good agreement with experimental data for isolated molecules, isolated

Marco Zoli

We study a molecular lattice Hamiltonian in which polaronic charge carriers interact with non linear potentials provided by local atomic fluctuations between two equilibrium sites. The path integral formalism is applied to select the class of atomic oscillations which mainly contributes to the partition function and the electrical resistivity is computed in

A. Calzolari, R. Di Felice, E. Molinari, a. Garbesi

We present a first principle study about the stability and the electronic properties of a new biomolecular solid-state material, obtained by the self-assembling of guanine (G) molecules. We consider hydrogen-bonded planar ribbons in isolated and stacked configurations. These aggregates present electronic properties similar to inorganic wide-bandgap semicondu

A. V. Silhanek, L. Civale, M. A. Avila

We have studied the angular dependence of the irreversible magnetization of several YBa$_2$Cu$_3$O$_7$ and 2H-NbSe$_2$ single crystals with columnar defects tilted off the c-axis. At high magnetic fields, the irreversible magnetization $M_i(Θ_H)$ exhibits a well known maximum when the applied field is parallel to the tracks. As the field is decreased below $

P. Paci, E. Cappelluti, C. Grimaldi, L. Pietronero

We investigate the issue of the nonadiabatic superconductivity in uncorrelated systems. A local approximation is employed coherently with the weak dependence on the involved momenta. Our results show that nonadiabatic vertex corrections are never negligible, but lead to a strong suppression of $T_c$ with respect to the conventional theory. This feature is un

S. V. Zaitsev-Zotov, M. S. H. Go, E. Slot, H. S. J. van der Zant

CDW/Normal metal/CDW junctions and nanoconstrictions in crystals of the quasi-one-dimensional conductor NbSe$_3$ are manufactured using a focused-ion-beam. It is found that the low-temperature conduction of these structures changes dramatically and loses the features of the charge-density-wave transition. Instead, a dielectric phase is developed. Up to 6-ord

Yung M. Huh, D. K. Finnemore

Vortex fluctuations in the $La_{2-x}Sr_{x}CuO_{4+δ}$ system have been studied as a function of magnetic field, temperature and carrier concentration in order to determine the dimensionality of the fluctuations. For a $x=0.10$ sample, there is a unique crossing-temperature on the magnetization vs. temperature plots for all magnetic fields up to 7 T, and the d

G. Kotliar, Sahana Murthy, M. J. Rozenberg

In the context of the dynamical mean field theory of the Hubbard model, we study the compressibility near the density driven Mott transition at finite temperatures. We demonstrate this divergence using dynamical mean field theory and Quantum Monte Carlo simulations in the one band and the two band Hubbard model. We supplement this result with considerations

A. S. Wills

The jarosites make up the most studied family of {\it kagomé} antiferromagnets. The flexibility of the structure to substitution of the A and B ions allows a wide range of compositions to be synthesised with the general formula AB3(SO4)2(OH)6 (A = Na$^+$, K$^+$, Ag$^+$, Rb$^+$, H3O$^+$, NH4$^+$, 1/2Ba$^{2+}$, and 1/2Pb$^{2+}$; B = Fe$^{3+}$, Cr$^{3+}$, and V

C. Talon, Q. W. Zou, M. A. Ramos, R. Villar

We have measured the thermal conductivity of glassy glycerol between 1.5 K and 100 K, as well as the specific heat of both glassy and crystalline phases of glycerol between 0.5 K and 25 K. We discuss both low-temperature properties of this typical molecular glass in terms of the soft-potential model. Our finding of an excellent agreement between its predicti

S. Kawasaki, T. Mito, G. -q. Zheng, C. Thessieu

We report the novel pressure($P$) - temperature($T$) phase diagram of antiferromagnetism and superconductivity in CeRhIn$_5$ and CeIn$_3$ revealed by the $^{115}$In nuclear-spin-lattice-relaxation ($T_1$) measurement. In the itinerant magnet CeRhIn$_5$, we found that the Néel temperature $T_N$ is reduced at $P \geq$ 1.23 GPa with an emergent pseudogap behavi

Hyun C. Lee, Han-Yong Choi

The electronic Raman scattering of Borocarbide superconductors is studied based on the weak coupling theory with $s+g$-wave gap symmetry. The low energy behaviors and the relative peak positions can be naturally understood, while the explanation of the detailed shape of the $B_{1g}$ peak seems to require a strong inelastic interaction not present in the weak

P. Nozieres, F. Pistolesi, S. Balibar

We consider the shape of crystals which are soft in the sense that their elastic modulus $μ$ is small compared to their surface tension $γ$, more precisely $ μa < γ$ where $a$ is the lattice spacing. We show that their surface steps penetrate inside the crystal as edge dislocations. As a consequence, these steps are broad with a small energy which we calcula

I. E. Psarobas, R. Sainidou, N. Stefanou, A. Modinos

We present a systematic study of the frequency band structure of acoustic waves in crystals consisting of nonoverlapping solid spheres in a fluid. We consider colloidal crystals consisting of polystyrene spheres in water, and an opal consisting of close-packed silica spheres in air. The opal exhibits an omnidirectional frequency gap of considerable width; th

A. A. Ovchinnikov

It has been shown that in metals and semiconductors the joint action of permanent magnetic and AC electric fields leads to arising of DC surface electric current. This is due to essentially non-linear dynamics of electronic gas in surface layer.The surface current is linear with respect to external magnetic field and depends quadratically on an amplitude of

M. Manninen, S. Viefers, M. Koskinen, S. M. Reimann

The yrast spectra (i.e. the lowest states for a given total angular momentum) of quantum dots in strong magnetic fields, are studied in terms of exact numerical diagonalization and analytic trial wave functions. We argue that certain features (cusps) in the many-body spectrum can be understood in terms of particle localization due to the strong field. A new

J. M. G. Vilar, J. M. Rubi

Nonequilibrium thermodynamics has shown its applicability in a wide variety of different situations pertaining to fields such as physics, chemistry, biology, and engineering. As successful as it is, however, its current formulation considers only systems close to equilibrium --those satisfying the so-called local equilibrium hypothesis. Here we show that dif

J. M. G. Vilar, J. M. Rubi

We have analyzed the interplay between an externally added noise and the intrinsic noise of systems that relax fast towards a stationary state, and found that increasing the intensity of the external noise can reduce the total noise of the system. We have established a general criterion for the appearance of this phenomenon and discussed two examples in deta

M. B. Hastings, Z. A. Daya, E. Ben-Naim, R. E. Ecke

We investigate experimentally the distribution of configurations of a ring with an elementary topological constraint, a ``figure-8&#39;&#39; twist. Using vibrated granular chains, which permit controlled preparation and direct observation of such a constraint, we show that configurations where one of the loops is tight and the second is large are strongly pr

R. Czerw, B. Foley, D. Tekleab, A. Rubio

By utilizing the current transients in scanning tunneling spectroscopy, the local interfacial electronics between multiwalled carbon nanotubes and several supporting substrates has been investigated. Voltage offsets in the tunneling spectra are directly correlated with the formation of a dipole layer at the nanotube-substrate interface strongly suggesting th

E. G. M. van Kempen, S. J. J. M. F. Kokkelmans, D. J. Heinzen, B. J. Verhaar

Combining the measured binding energies of four of the most weakly bound rovibrational levels of the $^{87}$Rb$_2$ molecule with the results of two other recent high-precision rubidium experiments, we obtain exceptionally strong constraints on the atomic interaction parameters in a highly model independent analysis. The comparison of $^{85}$Rb and $^{87}$Rb

Eli Eisenberg, Karsten Held, Boris L. Altshuler

Dephasing of one-particle states in closed quantum dots is analyzed within the framework of random matrix theory and Master equation. Combination of this analysis with recent experiments on the magnetoconductance allows for the first time to evaluate the dephasing times of closed quantum dots. These dephasing times turn out to depend on the mean level spacin

S. Bogner, T. Emig, T. Nattermann, S. Scheidl

In a recent letter Klein et al. [Nature 413, 404 (2001); cond-mat/0110018] provide experimental evidence for the existence of the Bragg glass phase in impure type II superconductors. Here we show that a more complete consideration of recent theoretical findings allows an even better interpretation of the experimental data.

Julio F. Navarro

Numerical simulations have revealed the presence of long-lived substructure in Cold Dark Matter (CDM) halos. These surviving cores of past merger and accretion events vastly outnumber the known satellites of the Milky Way. This finding has prompted suggestions that substructure in cold dark matter (CDM) halos may be incompatible with observation and in confl

Julio F. Navarro

I report on recent progress in our understanding of the structure of CDM halos, and in particular of the inner mass profile of galaxy-sized systems. Numerical simulations have consistently shown that the density profiles of CDM halos steepen monotonically from the center outwards, with slopes shallower than isothermal near the center and steeper than isother

Christopher Thompson

I summarize recent developments in the magnetar model of the Soft Gamma Repeaters and Anomalous X-ray Pulsars, give a critical inventory of alternative models for the AXPs, and outline the improved diagnostics expected from present observational efforts.

Kim-Vy Tran, Garth Illingworth, Marijn Franx

We combine HST WFPC mosaics of clusters at multiple redshifts with Keck LRIS spectroscopy to characterize different galaxy populations and how they evolve. By combining quantitative measurements of structural parameters with velocity dispersions, line indices, and morphological types, we attempt to establish links between ellipticals, S0&#39;s, E+A&#39;s, an

Christopher Thompson, Robert C. Duncan

(ABBREVIATED) The extraordinary 1998 August 27 giant flare places strong constraints on the physical properties of its source, SGR 1900+14. We make detailed comparisons of the published data with the magnetar model. The giant flare evolved through three stages, whose radiative mechanisms we address in turn. A triggering mechanism is proposed, whereby a helic

B. J. McCall, K. H. Hinkle, T. R. Geballe, G. H. Moriarty-Schieven

Surprisingly large column densities of H3+ have been detected using infrared absorption spectroscopy in seven diffuse cloud sightlines (Cygnus OB2 12, Cygnus OB2 5, HD 183143, HD 20041, WR 104, WR 118, and WR 121), demonstrating that H3+ is ubiquitous in the diffuse interstellar medium. Using the standard model of diffuse cloud chemistry, our H3+ column dens

Marc Sarzi, Hans-Walter Rix, Joseph C. Shields, Daniel H. McIntosh

We report upper limits on the masses of black holes that can be present in the centers of 16 nearby galaxy bulges. These limits for our statistically complete sample were derived from the modeling of the central emission-line widths ([N II] or [S II]), observed over a 0.25&#34; X 0.2&#34; (R < 9 pc) aperture. The experiment has a mean detection sensitivity o