We investigate the Penrose limit of various brane solutions including Dp-branes, NS5-branes, fundamental strings, (p, q) fivebranes and (p, q) strings. We obtain special null geodesics with the fixed radial coordinate (critical radius), along which the Penrose limit gives string theories with constant mass. We also study string theories with time-dependent mass, which arise from the Penrose lim...

The dynamics of a circular treadmilling low Reynolds number swimmer near a right-angled corner is studied in the asymptotic limit in which the radius of the treadmiller is small. The governing dynamical equations are found explicitly, correct to third order in the swimmer radius, by means of Mellin transform techniques. The existence of arc-like periodic orbits, or ‘hydrodynamic bound states’, ...

This paper uses an orthotropic shell model to investigate in detail the long axial wavelength circumferential vibration of microtubules (MTs). The deformation patterns in the vibrations were explored and their phonon dispersion relations were presented for MTs with increasing radius. It was shown that with the growth of the axial wavelength, the associated frequency of MTs would finally approac...

A neutrally buoyant particle in pipe flow is known to undergo a radial migration for finite Reynolds number flows. This effect was first observed by Segré and Silberberg (1962), who noted a radial equilibrium position at a radius r = 0.6R in a pipe of radius R, in conditions of finite but low Re. These results have been extended to show that the equilibrium position of the particles is moved to...

The residual dependence index of bivariate Gaussian distributions is determined by the correlation coefficient. This tail index is of certain statistical importance when extremes and related rare events of bivariate samples with asymptotic independent components are being modeled. In this paper we calculate the partial residual dependence indices of a multivariate elliptical random vector assum...

Among all sequences that satisfy a divide-and-conquer recurrence, the sequences that are rational with respect to a numeration system are certainly the most immediate and most essential. Nevertheless, until recently they have not been studied from the asymptotic standpoint. We show how a mechanical process permits to compute their asymptotic expansion. It is based on linear algebra, with Jordan...

Elliptic problems in a two-dimensional domain containing one or several small holes is studied asymptotically in the limit of small hole radius ". As a result of the perturbation , the asymptotic solution to this class of problems contains an innnite logarithmic expansion in powers of ?1= log ". A hybrid asymptotic-numerical technique is used to sum these innnite logarithmic expansions and obta...

The classical problem of the interaction of a non-emitting spherical body with a zero meanfree-path continuum plasma is solved numerically in the full range of physically allowed free parameters (electron Debye length to body radius ratio, ion to electron temperature ratio, and body bias), and analytically in rigorously defined asymptotic regimes (weak and strong bias, weak and strong shielding...

The classical problem of the interaction of a non-emitting spherical body with a zero meanfree-path continuum plasma is solved numerically in the full range of physically allowed free parameters (electron Debye length to body radius ratio, ion to electron temperature ratio, and body bias), and analytically in rigorously defined asymptotic regimes (weak and strong bias, weak and strong shielding...

In this paper we describe some analytical properties of the R1/m law proposed by Sersic (1968) to categorize the photometric profiles of elliptical galaxies. In particular, we present the full asymptotic expansion for the dimensionless scale factor b(m) that is introduced when referring the profile to the standard effective radius. Surprisingly, our asymptotic analysis turns out to be useful ev...