Comment on: “Evidence for the existence of stable-water-clusters at room temperature and normal pressure” [Phys. Lett. A 373 (2009) 3872]

We discuss some unclear issues in methodology and interpretation of the paper claiming to bring further evidence of so-called stable water clusters. We think that the evidence for the existence of stable water clusters is at best scant.     

Particle-hole excitations in the interacting boson model (III): The O(6)-SU(3) coupling

We apply the group theoretical concepts of the EIBM, an extension of the interacting boson model where a distinction is made between particle and hole bosons, to the particular situation of two coexisting systems in the same nucleus exhibiting the O(6) (regular states) and SU(3) (intruder states) symmetries. Besides giving evidence that such a coexisting set of states could well be applicable to the Pb region, we discuss the “global” symmetry properties of the above model. We also concentrate on mixing between the otherwise coexisting symmetries and point out how to make more realistic calculations. We discuss, at large, the experimental evidence in the Pb region for intruder analog multiplets.     

X-ray spectroscopy of cooling clusters

We review the X-ray spectra of the cores of clusters of galaxies. Recent high resolution X-ray spectroscopic observations have demonstrated a severe deficit of emission at the lowest X-ray temperatures as compared to that expected from simple radiative cooling models. The same observations have provided compelling evidence that the gas in the cores is cooling below half the maximum temperature. We review these results, discuss physical models of cooling clusters, and describe the X-ray instrumentation and analysis techniques used to make these observations. We discuss several viable mechanisms designed to cancel or distort the expected process of X-ray cluster cooling.     

Elastic energies for nematic elastomers

We discuss several elastic energies for nematic elastomers and their small strain expansions both in the regime of large director rotations, and in the case that director changes are small. We propose two fully non-linear model anisotropic energies and compare the behavior they predict with the currently available experimental evidence.     

On the hall resistivity of nHgCdTe

We discuss the measurements of the Hall resistivity of nHgCdTe and InSb which have demonstrated the similarity of the electronic properties of these two materials. Gebhardt and Nimitz [1] dispute the validity of our results. We cite the evidence that confirms the correctness of our original observations.     

Numerical study of the equilibrium thermodynamics of the Coulomb glass

We discuss the results of large‐scale Monte Carlo simulations of the lattice Coulomb glass model. Using the Exchange Monte Carlo algorithm we are able to equilibrate the system to very low temperature and obtain evidence against the existence of an equilibrium glass transition in three dimensions (3D). We also discuss results for the 3D Random Field Ising model that highlight the role of the interaction range. Finally, we report results for the 2D Coulomb glass, which show a behaviour very similar to the 3D case.     

Selecting wave function states in open quantum dots

We study how wave function scarring in an open quantum dot is influenced as the strength of its environmental coupling is varied and show evidence for groups of wave function scars that recur periodically with gate voltage. The precise form of these scars is found to evolve with gate voltage, which we discuss in terms of the properties of the semi-classical orbits that give rise to the scars. We also provide convincing experimental evidence for a correlation between the scars and the oscillations observed in the conductance when the gate voltage is varied.     

Extensions of perpendicular recording

Gains in storage density in magnetic recording have fundamentally been achieved by scaling—reduced geometrical dimensions under the assumption that the recording physics does not change if all dimensions are scaled appropriately. It is becoming clear that evidence of the breakdown of scaling is now seen. We will here discuss ways to break the constraints on magnetic recording set by scaling. In particular, we will discuss energy-assisted recording, domain-wall-assisted recording, and bit-patterned media, with some emphasis on recording system considerations.     

Anisotropic magnetic fluctuations in the ferromagnetic superconductor UCoGe studied by direction-dependent 59Co NMR measurements

We have carried out direction-dependent 59Co NMR experiments on a single crystal sample of the ferromagnetic superconductor UCoGe in order to study the magnetic properties in the normal state. The Knight-shift and nuclear spin-lattice relaxation rate measurements provide microscopic evidence that both static and dynamic susceptibilities are ferromagnetic with strong Ising anisotropy. We discuss that superconductivity induced by these magnetic fluctuations prefers spin-triplet pairing state.     

Effect of noise on chaos synchronization in time-delayed systems: Numerical and experimental observations

We discuss the constructive role of noise (white and colored) in chaos synchronization in time-delayed systems. We first numerically investigate noise-induced synchronization (NIS) between two identical uncoupled Ikeda and Mackey–Glass systems. We find that synchronization occurs above a critical noise intensity that differs for different colors of noise. Synchronization onset is characterized by the value of the maximum transverse Lyapunov exponent. We then discuss the enhancement of chaos synchronization between two time-delayed systems when they are coupled unidirectionally. The effect of parameter mismatch for NIS is described in detail. We provide experimental evidence of NIS for a Mackey–Glass-like system in an electronic circuit using different colors of noise. An integration scheme for time-delayed systems in the presence of additive white and colored noise is discussed.     

Partners for the E(1420)

We show that there is good evidence that the K′ and E mesons form part of a 0^?+ nonet, and discuss possible consequences for ψ and ψ′ decays.     

Axion-like particles and the propagation of gamma rays over astronomical distances

In this brief review, possible manifestations of mixing between axion-like particles (ALPs) and energetic photons propagating over astronomical distances are considered. We discuss the evidence for the anomalous transparency of the Universe from observations of ensembles of distant gamma-ray sources, present the general formalism for the ALP-photon mixing and explain how this mechanism may remove the anomaly. We present relevant values of ALP parameters and discuss future ways to verify the scenario and to discover the particle in question.     

Entanglement and criticality in translationally invariant harmonic lattice systems with finite-range interactions

We discuss the relation between entanglement and criticality in translationally invariant harmonic lattice systems with nonrandom, finite-range interactions. We show that the criticality of the system as well as validity or breakdown of the entanglement area law are solely determined by the analytic properties of the spectral function of the oscillator system, which can easily be computed. In particular, for finite-range couplings we find a one-to-one correspondence between an area-law scaling of the bipartite entanglement and a finite correlation length. This relation is strict in the one-dimensional case and there is strong evidence for the multidimensional case. We also discuss generalizations to couplings with infinite range. Finally, to illustrate our results, a specific 1D example with nearest and next-nearest-neighbor coupling is analyzed.     

Interband pairs and reduced Josephson current: a comment on tunnelling experiments in two-band superconductors

Summary Tunnelling experiments in superconductors involving interband pair states are considered. We discuss qualitatively the results obtained in heavy-fermion systems which could be understood as an evidence of this unusual ground state.     

Reply to “comments on the paper ‘anti-stokes luminescence in Europium monochalcogenides’”

We discuss the assignment made in a previous paper by D. Hulin and C. Benoit à la Guillaume concerning one of the lines observed in the photoluminescence of EuO. We present further experimental evidence which discards the involvement of magnons in the luminescence process.     

Phase reduction of stochastic limit cycle oscillators

We point out that for an oscillator subjected to noise the conventional phase equation is not a proper approximation even for weak noise. We present a phase reduction method valid for an oscillator subjected to weak white Gaussian noise. Numerical evidence demonstrates that the phase equation properly approximates dynamics of the original oscillator. Moreover, we show that, in general, noise causes a shift of the oscillator frequency and discuss its effects on entrainment.     

High pressure insulator-metal transition in molecular fluid oxygen

We report the first experimental evidence for a metallic phase in fluid molecular oxygen. Our electrical conductivity measurements of fluid oxygen under dynamic quasi-isentropic compression show that a nonmetal-metal transition occurs at 3.4 fold compression, 4500 K, and 1.2 Mbar. We discuss the main features of the electrical conductivity dependence on density and temperature and give an interpretation of the nature of the electrical transport mechanisms in fluid oxygen at these extreme conditions.     

The role of bound states in time-dependent quantum transport

Charge transport through a nanoscale junction coupled to two macroscopic electrodes is investigated for the situation when bound states are present. We provide numerical evidence that bound states give rise to persistent, non-decaying current oscillations in the junction. We also show that the amplitude of these oscillations can exhibit a strong dependence on the history of the applied potential as well as on the initial equilibrium configuration. Our simulations allow for a quantitative investigation of several transient features. We also discuss the existence of different timescales and address their microscopic origin.     

Identification of the glueballs and the scalar meson nonet of lowest mass

We discuss the theoretical expectations and phenomenological evidence for the lightest glueballs and the members of the meson nonet with quantum numbers . We reconsider the recent evidence for candidate states with masses below 1700 MeV, but include also the results from earlier phase-shift analyses. Arguments are presented to classify the scalars and as members of the nonet, with a mixing rather similar to that of the pseudoscalars and . The S-wave states called and are considered as different signals from a single broad resonance, which we take to be the lowest-lying glueball. This state together with and with spin form the basic triplet of binary gluonic bound states. We argue that these hypotheses are consistent with what can be expected theoretically. Received: 30 November 1998 / Revised version: 17 February 1999 / Published online: 27 April 1999     

Parton evolution and saturation in deep inelastic scattering

We review the evidence for saturation seen at HERA, and we discuss a few theoretical aspects of saturation in deep inelastic electron proton scattering.Arrival of the final proofs: 21 June 2005PACS: 12.38.Bx,12.38.-t,12.38.Cy