Simulating the effect of carbon nanotube curvature on adsorption of polycyclic aromatic hydrocarbons

The results of Molecular Dynamics simulation of polycyclic aromatic hydrocarbons adsorption on single-walled (13,9) carbon nanotube are reported. We discuss the angular orientation and plausible adsorbed states of molecules. It is shown, that suggested by Gotovac et al. orientation of adsorbed molecules is correct.     

Construction of <Emphasis Type=Italic>N</Emphasis>-Body Initial Data Sets in General Relativity

Given a collection of N solutions of the (3 + 1) Einstein constraint equations which are asymptotically Euclidean and vacuum near infinity, we show how to construct a new solution of the constraints which is itself asymptotically Euclidean, and which contains specified sub-regions of each of the N given solutions. This generalizes earlier work which handled the time-symmetric case, thus providing a construction of large classes of initial data for the many body problem in general relativity.     

New classes of self-similar symmetric stable random fields

We construct two new classes of symmetric stable self-similar random fields with stationary increments, one of the moving average type, the other of the harmonizable type. The fields are defined through an integral representation whose kernel involves a norm on ⁿ . We examine how the choice of the norm affects the finite-dimensional distributions. We also study the processes which are obtained by projecting the random fields on a one-dimensional subspace. We compare these projection processes with each other and with other well-known self-similar processes and we characterize their asymptotic dependence structure.The research was done at Boston University while the first author was on leave from the Hugo Steinhaus Center, Poland. The second author was partially supported by the ONR Grant N00014-90-J-1287 at Boston University and by a grant of the United States-Israel Binational Science Foundation.     

Segre classes of a vector bundle spanned by global sections

We show that the Segre polynomial determines the minimal number of sections spanning a vector bundle spanned by global sections.The author was an NSERC Postdoctoral Fellow while preparing this paper.     

The influence of rotational depolarization on the mechanism of energy transport in two-component systems: The nature of correlations

The correlation effect in two-component systems of different viscosities was analyzed based on a concentration depolarization experiment. The inclusion of a correlation effect was found to be fully justified only in systems for which the localization time, _l, is considerably shorter than that of the rotational relaxation, _rot. On the grounds of an approximate analysis, taking into account the competition between the concentration and the rotational depolarization, it was possible to explain the concentration changes in the emission anisotropy in the systems investigated.Dedicated to Professor Czestaw Bojarski on the occasion of his 70th birthday.     

Nonlocality in (1/N)-expanded nonrenormalizable interactions

Nonrenormalizable interactions are studied on the example of the (1/N) ₆ ⁴ model with interaction via the collective = ² mode. In 4<d<6 dimensions, the model is nonrenormalizable by power counting but it does not require more subtractions than in the four-dimensional case. In six dimensions, nonrenormalizability is essential: There are two induced couplings ³ and . The ³ coupling strength can be determined from the requirement that the effective potential has a minimum at ² = = 0. The nonlocal formafactor produced by an infinite number of insertions cannot be determined uniquely, however the ambiguity concentrates in the leading order only. We construct this formfactor using the method of Efimov and Mogilevsky. The resulting theory satisfies unitarity, microcausality and correct spectral properties.     

Properties of nucleons in the relativistic quark model with strong binding

Baryons are considered as the strongly bound system of three heavy quarks. The dynamics of the model is described by the Bethe-Salpeter equation with harmonic oscillator interaction. Two different spin structures of the interaction kernels (taken from the meson case) are considered. It is found that one of them fails to reproduce the spectrum of baryons in the ground state. The second spin structure reproduces the spectrum. The model gives good results for the magnetic moments of nucleons and for the weak currents matrix element between the neutron and proton. It is also shown that the properties of quark in our model are similiar to those of the quark model for mesons and thus both these models can be treated together.     

Projective Module Description of the q-Monopole

The Dirac q-monopole connection is used to compute projector matrices of quantum Hopf line bundles for arbitrary winding number. The Chern–Connes pairing of cyclic cohomology and K-theory is computed for the winding number −1. The non-triviality of this pairing is used to conclude that the quantum principal Hopf fibration is non-cleft. Among general results, we provide a left-right symmetric characterization of the canonical strong connections on quantum principal homogeneous spaces with an injective antipode. We also provide for arbitrary strong connections on algebraic quantum principal bundles (Hopf–Galois extensions) their associated covariant derivatives on projective modules. Received: Received: 4 September 1998 / Accepted: 16 October 1998