Supertubes and Supercurves from M-Ribbons

We construct 1/4 BPS configurations, `M-ribbons', in M-theory on T^2, which give the supertubes and supercurves in type IIA theory upon dimensional reduction. These M-ribbons are generalized so as to be consistent with the SL(2,Z) modular transformation on T^2. In terms of the type IIB theory, the generalized M-ribbons are interpreted as an SL(2,Z) duality family of super D-helix. It is also shown that the BPS M-ribbons must be straight in one direction.Comment: 10 pages, 1 figure, references added, footnote added, BPS eq. (36) is examined without using the solution of field equations, some expressions are improve

Phase Moduli Space of Supertubes

We study possible deformations of BPS supertubes keeping their conserved charges fixed. We show that there is no flat direction to closed supertubes of circular cross section with uniform electric and magnetic fields, and also to open planar supertubes. We also find that there are continuously infinite flat deformations to supertubes of general shape under certain conditions.Comment: 12 pages, reference adde

Supertubes connecting D4 branes

We find and explore a class of dyonic instanton solutions which can be identified as the supertubes connecting two D4 branes. They correspond to a single monopole string and a pair of monopole antimonopole strings from the worldvolume view point of D4 branes.Comment: 12 pages, no figures, a reference adde

Field Theory Supertubes

Starting with intersecting M2-branes in M-theory, the IIA supertube can be found by compactification with a boost to the speed of light in the compact dimension. A similar procedure applied to Donaldson-Uhlenbeck-Yau instantons on \bC^3, viewed as intersecting membranes of 7D supersymmetric Yang-Mills (SYM) theory, yields (for finite boost) a new set of 1/4 BPS equations for 6D SYM-Higgs theory, and (for infinite boost) a generalization of the dyonic instanton equations of 5D SYM-Higgs theory, solutions of which are interpreted as Yang-Mills supertubes and realized as configurations of IIB string theory.Comment: 11 pages. Contribution to Strings '04. Revised to include minor corrections and additional reference

Tubular Solutions of Dirac-Born-Infeld Action on Dp-Brane Background

We use the Dirac-Born-Infeld action on Dp-brane background to find the tubular bound state of a D2 with $m$ D0-branes and $n$ fundamental strings. The fundamental strings may be the circular strings along the cross section of tube or the straight strings along the axial of the tube, and tube solutions are parallel to the geometry of Dp-brane background. Through the detailed analyses we show that only on the D6-brane background could we find the stable tubular solutions. These tubular configurations are prevented form collapse by the gravitational field on the curved Dp-brane background.Comment: Latex 11 pages, detail RR-field effect, delete figure 4 and associated par

Supersymmetric Brane-Antibrane Configurations

We find a class of flat supersymmetric brane-antibrane configurations. They follow from ordinary brane-antibrane systems by turning on a specific worldvolume background electric field, which corresponds to dissolved fundamental strings. We have clarified in detail how they arise and identified their constituent charges as well as the corresponding supergravity solutions. Adopting the matrix theory description, we construct the worldvolume gauge theories and prove the absence of any tachyonic degrees. We also study supersymmetric solitons of the worldvolume theories.Comment: 17 pages, a reference added, minor sign errors correcte

Universal local versus unified global scaling laws in the statistics of seismicity

The unified scaling law for earthquakes, proposed by Bak, Christensen, Danon and Scanlon, is shown to hold worldwide, as well as for areas as diverse as Japan, New Zealand, Spain or New Madrid. The scaling functions that account for the rescaled recurrence-time probability densities show a power-law behavior for long times, with a universal exponent about (minus) 2.2. Another decreasing power law governs short times, but with an exponent that may change from one area to another. This is in contrast with a spatially independent, time-homogenized version of Bak et al's procedure, which seems to present a universal scaling behavior.Comment: submitted to Per Bak's memorial issue of Physica