Spacetime-Filling Branes and Strings with Sixteen Supercharges

We discuss branes whose worldvolume dimension equals the target spacetime dimension, i.e. ``spacetime-filling branes''. In addition to the D9-branes, there are 9-branes in the NS-NS sectors of both the IIA and IIB strings. The worldvolume actions of these branes are constructed, via duality, from the known actions of branes with codimension larger than zero. Each of these types of branes is used in the construction of a string theory with sixteen supercharges by modding out a type II string by an appropriate discrete symmetry and adding 32 9-branes. These constructions are related by a web of dualities and each arises as a different limit of the Horava-Witten construction.Comment: 43 pages, LaTeX, 8 figures, uses html.sty, version to appear in Nucl. Phys.

Women in Early Analytic Philosophy: Volume Introduction

Editor's Introduction to the special issue including papers about Susan Stebbing, Susanne Langer and Maria Kokoszyńska

Domain Walls on the Brane

We show that all branes admit worldvolume domain wall solutions. We find one class of solutions for which the tension of the brane changes discontinuously along the domain wall. These solutions are not supersymmetric. We argue that there is another class of domain wall solutions which is supersymmetric. A particular case concerns supersymmetric domain wall solutions on IIB D-5- and NS-5-branes.Comment: 18 pages, Tex, uses phyzz

Oscillations in the bispectrum

There exist several models of inflation that produce primordial bispectra that contain a large number of oscillations. In this paper we discuss these models, and aim at finding a method of detecting such bispectra in the data. We explain how the recently proposed method of mode expansion of bispectra might be able to reconstruct these spectra from separable basis functions. Extracting these basis functions from the data might then lead to observational constraints on these models.Comment: 6 pages, 2 figures, submitted to JOP: Conference Series, PASCOS 201

Forced motion of a probe particle near the colloidal glass transition

We use confocal microscopy to study the motion of a magnetic bead in a dense colloidal suspension, near the colloidal glass transition volume fraction $\phi_g$. For dense liquid-like samples near $\phi_g$, below a threshold force the magnetic bead exhibits only localized caged motion. Above this force, the bead is pulled with a fluctuating velocity. The relationship between force and velocity becomes increasingly nonlinear as $\phi_g$ is approached. The threshold force and nonlinear drag force vary strongly with the volume fraction, while the velocity fluctuations do not change near the transition.Comment: 7 pages, 4 figures revised version, accepted for publication in Europhysics Letter

Multiple Intersections of D-branes and M-branes

We give a classification of all multiple intersections of D-branes in ten dimensions and M-branes in eleven dimensions that corresponds to threshold BPS bound states. The residual supersymmetry of these composite branes is determined. By dimensional reduction composite p-branes in lower dimensions can be constructed. We emphasize in dimensions D greater or equal than two, those solutions which involve a single scalar and depend on a single harmonic function. For these extremal branes we obtain the strength of the coupling between the scalar and the gauge field. In particular we give a D-brane and M-brane interpretation of extreme p-branes in two, three and four dimensions.Comment: 28 pages, LaTeX, 4 figures, corrections in table 1 and figure