Tachyon kinks

We study Born-Infeld type tachyonic effective action of unstable D2-branewith a runaway potential and find rich structure of static regular solitonicsolutions. There exists only periodic array of tachyon kink-antikinks in puretachyonic theory, however, in the presence of electromagnetic fields, solutionsinclude periodic arrays, topological tachyon kinks, half kink, and bounces.Computed tension of each kink or single unit of the periodic array has$T_{1}=\sqrt{2}\pi T_{2}$ or that with a multiplicative factor depending onelectric field. When both electric and magnetic fields are turned on,fundamental string charge density has a confined component in addition to aconstant piece. These evidences imply that the obtained codimension-1 objectsare likely to be interpreted as D1-brane (and D1F1) or array of D1$\bar{{\rmD}}1$ (and D1F1-$\bar{{\rm D}}1$F1) as was the case without the electromagneticfields. Generalization to unstable D$p$-branes is straightforward.Comment: LaTeX, 26 pages, 9 figure